Positive electrode material powder, method for manufacturing same, and lithium secondary battery comprising same

Abstract

The present invention provides a positive electrode material powder containing particles of a lithium nickel-based oxide represented by chemical formula 1 and having a single crystallinity of 1.85 to 3.00 as expressed by equation (1) according to the present invention. [Chemical formula 1] LiaNibCocM1 dM2 eO2 In chemical formula 1, M1 is Mn, Al, or a combination thereof, M2 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, 0.80≤a≤1.20, 0.80≤b<1, 0<c<0.45, 0<d<0.45, and 0≤e≤0.20.

Description

Cathode material powder, method for producing same, and lithium secondary battery comprising same Cross-citation with related applications This application claims the benefit of priority from Korean Patent Application No. 10-2023-0124865, dated September 19, 2023, the entire contents of which are incorporated herein by reference. Technology field The present invention relates to a cathode material powder, a method for producing the same, and a lithium secondary battery comprising the same. More specifically, the present invention relates to a cathode material powder capable of improving high-temperature characteristics, a method for producing the same, and a lithium secondary battery comprising the same. A lithium secondary battery is generally composed of a positive electrode, a negative electrode, a separator, and an electrolyte, and the positive electrode and negative electrode include an active material capable of intercalating and deintercalating lithium ions. Lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMnO2 or LiMnO4, etc.), and lithium iron phosphate compound (LiFePO4) have been used as cathode active materials for lithium secondary batteries. Among these, lithium cobalt oxide has the advantages of high operating voltage and excellent capacity characteristics, but the high price of cobalt, which is the raw material, and its supply are unstable, making it difficult to commercially apply it to large-capacity batteries. Lithium nickel oxide has poor structural stability, making it difficult to achieve sufficient cycle life characteristics. Meanwhile, lithium manganese oxide has excellent stability but has the problem of poor capacity characteristics. Therefore, lithium composite transition metal oxides containing two or more transition metals have been developed to complement the problems of lithium transition metal oxides containing only Ni, Co, or Mn. Among these, lithium nickel cobalt manganese oxide containing Ni, Co, and Mn is widely used in the field of electric vehicle batteries. Conventional lithium nickel cobalt manganese oxides are generally in the form of spherical secondary particles formed by agglomeration of tens to hundreds of primary particles. However, when lithium nickel cobalt manganese oxides formed in the form of secondary particles formed by agglomeration of many primary particles are used, there is a problem in that the primary particles are likely to break during the rolling process during the manufacture of the positive electrode, and cracks may occur inside the particles during the charge and discharge process. When the positive electrode active material particles break or crack, the contact area with the electrolyte increases, which increases gas generation and active material degradation due to side reactions with the electrolyte, and this causes problems in that the life characteristics are reduced. Meanwhile, demand for high-power, high-capacity batteries, such as those for electric vehicles, is increasing. Consequently, there's a growing trend toward increasing electrode density to achieve these higher-capacity batteries. However, while increasing electrode density improves capacity characteristics, it also increases the generation of fine particles due to particle breakage during electrode rolling. This, in turn, increases the surface area for reaction with the electrolyte, leading to electrolyte decomposition and deterioration of the active material surface structure during charge / discharge. To address the above issues, a technique has been proposed for producing single-particle cathode active materials, rather than secondary particles, by increasing the sintering temperature during the production of lithium nickel cobalt manganese oxide. Single-particle cathode active materials exhibit less side reactions with the electrolyte than conventional secondary-particle cathode active materials due to their smaller contact area with the electrolyte. Therefore, the application of single-particle cathode active materials offers the advantages of reduced gas generation and superior cycle life. However, conventional single particle type positive electrode active materials have problems such as generating a large amount of gas at high temperatures or having low life characteristics. The present invention is intended to solve the above problems, and provides a cathode material powder having excellent lifespan characteristics and low gas generation at high temperatures, a method for producing the same, and a lithium secondary battery including the same. [1] The present invention provides a cathode material powder comprising lithium nickel-based oxide particles represented by the following chemical formula 1 and having a single crystallinity of 1.85 to 3.00 represented by the following chemical formula (1). [Chemical Formula 1] Li a Ni b Co c M 1 d M 2 e O2 In the above chemical formula 1, M 1 is Mn, Al or a combination thereof, and M 2 It may be at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.80≤a≤1.20, 0.80≤b<1, 0 <c<0.45, 0<d<0.45, 0≤e≤0.20이다. Equation (1): Single crystallinity = In the above equation (1), A k is the area of ​​the kth grain measured when an electrode manufactured by applying the above cathode material powder is subjected to ion milling treatment and then the electrode cross-section is analyzed by backscatter electron diffraction (EBSD), and n is the total number of grains measured through the backscatter electron diffraction (EBSD) analysis and is 200 to 500. [2] In the present invention, in the above [1], the chemical formula 1 may be represented by the following chemical formula 1-1. [Chemical Formula 1-1] Li a1 Ni b1 Coc1 Mn d1 Al d2 M 2 e1 O2 In the above chemical formula 1-1, M 2 It may be at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.80≤a1≤1.20, 0.85≤b1<1, 0 <c1<0.45, 0<d1<0.18, 0<d2<0.15, 0≤e1≤0.20, 0<d1+d2<0.33일 수 있다. [3] In the present invention, in the above [1] or [2], the specific surface area of ​​the positive electrode powder is 0.40 m 2 / g to 0.75m 2 / g may be. [4] In at least one of the above [1] to [3], the rolling density of the cathode material powder may be 2.9 g / cc to 3.2 g / cc. [5] In at least one of the above [1] to [4], the cathode material powder may have a fine particle generation rate of 1 μm or less of 6% by volume or less when pressurized at 9 tons. [6] The present invention relates to at least one of the above [1] to [5], wherein the average particle diameter (D) of the positive electrode powder 50 ) may be 2㎛ to 5㎛. [7] In at least one of the above [1] to [6], the cathode material powder may have a single crystallinity of 2.0 to 2.5 as represented by formula (1). [8] The present invention provides a method for manufacturing a cathode material powder according to at least one of [1] to [7], comprising: (S1) a step of mixing a cathode active material precursor and a lithium source and then performing a first firing; and (S2) a step of performing a second firing on the first fired product, wherein the first firing step is performed at 850°C to 960°C for 10 to 20 hours, and the second firing step sequentially includes a first holding section maintained at 720°C to 850°C, a second holding section maintained at 900°C to 970°C, and a third holding section maintained at 720°C to 850°C, wherein the cathode active material precursor has a nickel content of 80 mol% or more among all metals excluding lithium. [9] In the present invention, in the above [8], the first firing step may be performed at 870°C to 960°C for 10 to 15 hours.

[0010] In the present invention, in the above [8] or [9], the first maintenance section and the third maintenance section may be independently maintained for 5 to 10 hours.

[0011] In at least one of the above [8] to

[0010] , the second maintenance period may be maintained for 5 to 60 minutes.

[0012] In at least one of the above [8] to

[0011] , the total firing time of the second firing step may be 10 to 15 hours.

[0013] The present invention provides a lithium secondary battery comprising a positive electrode comprising at least one positive electrode powder among the above [1] to [7]; a negative electrode; a separator; and an electrolyte. The cathode material powder according to the present invention is characterized in that it satisfies the range of 1.85 to 3.00 in terms of the degree of single crystallinity represented by Equation (1). In the case of a lithium secondary battery using the cathode material powder having a degree of single crystallinity represented by Equation (1) of less than 1.85 or greater than 3.00, the amount of gas generated during high-temperature storage is high and the high-temperature life characteristics are deteriorated. In comparison, a lithium secondary battery using a cathode material powder having a single crystallinity satisfying the range of the present invention exhibits excellent high-temperature life characteristics and high-temperature storage characteristics. Figure 1 is an SEM image of a cross-section of an electrode manufactured using a cathode material powder manufactured according to Example 1 of the present invention. Figure 2 is an SEM image of a cross-section of an electrode manufactured using a cathode material powder manufactured according to Example 2 of the present invention. Figure 3 is an SEM image of a cross-section of an electrode manufactured using the cathode material powder manufactured by Comparative Example 2 of the present invention. Figure 4 is an SEM image of a cross-section of an electrode manufactured using a cathode material powder manufactured according to Example 1 of the present invention, which is an image obtained by performing EBSD analysis. Figure 5 is an SEM image of a cross-section of an electrode manufactured using a cathode material powder manufactured according to Example 2 of the present invention, which is an image obtained by performing EBSD analysis. Figure 6 is an SEM image of a cross-section of an electrode manufactured using the cathode material powder manufactured by Comparative Example 2 of the present invention, which is an image obtained by performing EBSD analysis. 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, a "grain" is a particle unit having the same crystal orientation, and is the smallest particle unit recognized as a single lump in an Electron Backscatter Diffraction (EBSD) map image. The size of a grain can be measured by image analysis of an EBSD map. In the present invention, “single particle” means a particle composed of one nodule, and “quasi-single particle” means a composite particle composed of 30 or fewer nodules. The above "nodule" is a sub-particle unit that constitutes a single particle and a pseudo-single particle, and may be a single crystal without a crystalline grain boundary, or a polycrystal with no apparent grain boundary when observed under a magnification of 5,000 to 20,000 times using a scanning electron microscope. In the present invention, "secondary particle" refers to a particle formed by agglomeration of a plurality of primary particles, for example, tens to hundreds of primary particles. Specifically, the secondary particle may be an aggregate of 50 or more primary particles. In the present invention, “particle” is a concept including any one or all of a single particle, a pseudo-single particle, a primary particle, a nodule, and a secondary particle. In the present invention, the “specific surface area” is measured by the BET method, and specifically, can be calculated from the nitrogen gas adsorption amount at liquid nitrogen temperature (77K) using BELSORP-mini II of BEL Japan. In the present invention, "average particle diameter D 50"It refers to the particle size at 50% of the volume cumulative particle size distribution of the cathode powder, and can be measured using the laser diffraction method. For example, after dispersing the cathode powder in a dispersion medium, it can be measured by introducing it into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000), irradiating it with ultrasonic waves of about 28 kHz at an output of 60 W, obtaining a volume cumulative particle size distribution graph, and then calculating the particle size corresponding to 50% of the volume cumulative amount. The inventors of the present invention have conducted repeated research to develop a cathode material having excellent high-temperature characteristics, and as a result, have discovered that excellent high-temperature characteristics can be realized when the ratio of the sum of the squares of the grain areas to the sum of the grain areas of the cathode material powder satisfies a specific relationship, thereby completing the present invention. Hereinafter, the present invention will be described in detail. The cathode material powder according to the present invention, the method for producing the same, and the lithium secondary battery including the same comprise at least one of the following disclosed configurations, and may comprise any combination between technically possible configurations among the following configurations. cathode powder Hereinafter, the cathode material powder according to the present invention will be described. The cathode material powder according to the present invention has a single crystallinity of 1.85 to 3.00, as represented by the following formula (1). Equation (1): Single crystallinity = In the above equation (1), A k is the area of ​​the kth grain measured when analyzing the backscatter electron diffraction (EBSD) of the electrode cross-section obtained by ion milling the electrode manufactured by applying the above cathode material powder, and the unit is ㎛. 2 is the value measured. Specifically, the above Ak The value can be obtained through the software of the EBSD device. In addition, the above A k 2 A obtained by the method described above k , which means the square of the area of ​​the kth grain. Meanwhile, A is substituted into the above equation (1) k Wow A k 2 is a dimensionless number that does not include units. The above n is the total number of grains measured through the backscatter electron diffraction (EBSD) analysis, and may be 200 to 500, preferably 250 to 450, and more preferably 300 to 400. If the total number of measured grains is too small, it may not represent the grain size tendency of the entire cathode material powder, and if it is too large, the measurement accuracy may decrease. Electron Backscatter Diffraction (EBSD) analysis is a method of measuring the crystallographic phase and crystallographic orientation of a sample using the diffraction pattern, and analyzing the crystallographic information of the sample based on this. When the sample is tilted at a large angle with respect to the incident direction of the electron beam in a scanning electron microscope, the incident electron beam is scattered within the sample, resulting in a diffraction pattern appearing toward the sample surface. This is called an Electron Backscatter Diffraction Pattern (EBSP). Since the backscatter electron diffraction pattern responds to the crystal orientation of the area irradiated with the electron beam, it can be used to accurately measure the crystal orientation of a sample, and an EBSD IPF map (inverse pole figure map) can be obtained, which is divided into grains with the same crystal orientation. In addition, the IPF map can be image analyzed using the EBSD software to obtain information such as grain size, shape, and orientation. In the present invention, for EBSD analysis of positive electrode powder, an electrode for EBSD analysis is manufactured using the positive electrode powder to be analyzed, the manufactured electrode is cut by ion milling, and then an electron beam is irradiated on the cut electrode cross-section to perform EBSD analysis. Specifically, the electrode for EBSD measurement can be manufactured by mixing the positive electrode powder to be analyzed, a conductive agent, and a binder in N-methyl pyrrolidone to manufacture an electrode slurry, applying the electrode slurry onto an aluminum current collector, and then drying it. Meanwhile, a rolling process is not performed when manufacturing the electrode for EBSD analysis. This is because, if a rolling process is performed, deformation and breakage may occur in the positive electrode active material particles. Figures 4 to 6 illustrate IPF map images obtained by cutting electrodes manufactured using the positive electrode powders of Examples 1 to 2 and Comparative Example 2 described below using ion milling and then performing EBSD analysis on the cross-sections. As shown in Figures 4 to 6, images segmented by grain unit can be obtained through EBSD analysis. According to the research of the present inventors, it was found that when the degree of single crystallinity represented by the above formula (1) satisfies a specific range, the effect of simultaneously improving high-temperature storage and high-temperature life characteristics can be obtained. The degree of single crystallinity represented by the above formula (1) is 1.85 to 3.00. Preferably, it may be 1.9 to 2.8, and more preferably, it may be 2.0 to 2.5. The above formula (1) is the sum of the squares of the areas of the grains that appear during EBSD analysis divided by the sum of the areas of the grains. When the above formula (1) is less than 1.85, the reaction area of ​​the positive electrode powder that reacts with the electrolyte increases, accelerating the decomposition of the electrolyte and the deterioration of the surface structure, so there is a problem that the high-temperature storage characteristics and life characteristics are deteriorated. When the above formula (1) is more than 3.00, the movement distance for lithium ions to diffuse into the particle increases, so that the lithium mobility is deteriorated, and this causes an imbalance of lithium ions between the inside and outside of the particle during charge / discharge, so there is a problem that the high-temperature storage characteristics and life characteristics are deteriorated. Therefore, when a lithium secondary battery is manufactured by applying a positive electrode powder that satisfies the above range, it was found that both the high-temperature storage characteristics and the high-temperature life characteristics are excellent. The degree of single crystallinity expressed by the above formula (1) can be controlled by various methods, but preferably, it can be controlled by the number of moles of nickel contained in the lithium nickel-based oxide particles, the type of raw material used in the manufacture of the cathode material powder, the mixing ratio, the sintering stage, the sintering temperature, the sintering time, the sintering atmosphere, etc. Meanwhile, the cathode material powder according to the present invention includes lithium nickel-based oxide particles represented by the following [chemical formula 1]. [Chemical Formula 1] Li a Ni b Co c M 1 d M 2 e O2 In the above [chemical formula 1], M 1 is Mn, Al or a combination thereof, preferably Mn or a combination of Mn and Al, and more preferably a combination of Mn and Al. Above M 2 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, preferably at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Sr, W, and Nb, and more preferably at least one selected from the group consisting of Ti, Mg, Al, Zr, and Y. M 2 Although elements are not essential, when included in appropriate amounts, they can play a role in promoting particle growth or improving crystal structure stability during sintering. The above a represents the molar ratio of lithium in the lithium nickel-based oxide particles, and may be 0.80≤a≤1.20, 0.90≤a≤1.10, or 0.95≤a≤1.15. When the molar ratio of lithium satisfies the above range, a stable layered crystal structure can be formed. The above b represents the molar ratio of nickel among the total metal excluding lithium in the lithium nickel-based oxide particles, and may be 0.80≤b<1, 0.82≤b<1, or 0.85≤b<1. When the molar ratio of nickel satisfies the above range, the capacity characteristics are excellent, and in particular, when the nickel molar ratio is 0.80 or more, even better capacity characteristics can be realized, and when the nickel molar ratio is less than 0.80, there is a problem that it is difficult to realize the single crystallinity expressed by the above formula (1). The above c represents the molar ratio of cobalt among all metals excluding lithium in lithium nickel oxide particles, and is 0. <c<0.45, 0<c<0.40, 0<c<0.20, 또는 0<c<0.18일 수 있다. The above d is M of all metals except lithium in lithium nickel oxide particles. 1 It represents the molar ratio of elements, 0 <d<0.45, 0<d<0.40, 0<d<0.33, 0<d<0.25, 0<d<0.20, 또는 0<d<0.18일 수 있다. The above e is M of all metals except lithium in lithium nickel oxide particles. 2 It represents the molar ratio of elements, and can be 0≤e≤0.20, 0≤e≤0.15, or 0≤e≤0.10. More preferably, the above [chemical formula 1] may be represented by the following [chemical formula 1-1]. [Chemical Formula 1-1] Li a1 Ni b1 Co c1 Mn d1 Al d2 M 2 e1 O2 In the above chemical formula 1-1, M 2is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.80≤a1≤1.20, 0.80≤b1<1, 0 <c1<0.18, 0<d1<0.18, 0<d2<0.15, 0≤e1≤0.20, 0<d1+d2<0.33일 수 있으며, 바람직하게는, 0.80≤a1≤1.20, 0.82≤b1<1, 0<c1<0.15, 0<d1<0.15, 0<d2<0.10, 0≤e1≤0.10, 0<d1+d2<0.25일 수 있고, 보다 바람직하게는, 0.80≤a1≤1.20, 0.85≤b1<1, 0<c1<0.15, 0<d1<0.15, 0<d2<0.10, 0≤e1≤0.10, 0<d1+d2<0.25일 수 있다. 리튬 니켈계 산화물 입자가 상기 [화학식 1-1]의 조성을 가질 경우, 양극 활물질의 구조 안정성 및 용량 특성이 우수하게 나타난다. Meanwhile, the cathode material powder may further include a coating layer formed on the surface of the lithium nickel-based oxide particle and including at least one coating element selected from the group consisting of Al, Ti, W, B, F, P, Mg, Ni, Co, Fe, Cr, V, Cu, Ca, Zn, Zr, Nb. Mo, Sr, Sb, Bi, Si, and S. When a coating layer exists on the surface of lithium nickel-based oxide particles, contact between the electrolyte and lithium nickel-based oxide particles is suppressed by the coating layer, thereby reducing the elution of transition metals or gas generation due to side reactions with the electrolyte. Meanwhile, the lithium nickel-based oxide particles of the present invention may be single particles composed of one nodule and / or quasi-single particles which are composites of 30 or fewer, preferably 2 to 20, and more preferably 2 to 10 nodules, or may be in a form including them. Preferably, the cathode material powder according to the present invention may be composed of a combination of single particles and quasi-single particle-type cathode active material particles. When the number of nodules constituting the cathode active material particles exceeds 30, particle breakage increases during electrode manufacturing, and the occurrence of internal cracks due to volume expansion / contraction of the nodules during charge / discharge increases, which may deteriorate the effect of improving high-temperature life characteristics and high-temperature storage characteristics. Meanwhile, the specific surface area of ​​the above cathode material powder is 0.40 m 2 / g to 0.75m 2 / g may be, preferably 0.45m 2 / g to 0.70m 2 / g, more preferably 0.50m 2 / g to 0.70m 2 / g. When the above BET specific surface area range is satisfied, side reactions with the electrolyte can be appropriately reduced to reduce gas generation and improve the high-temperature life performance of the battery. Meanwhile, the rolling density of the cathode material powder may be 2.9 g / cc to 3.2 g / cc, and preferably 2.95 g / cc to 3.1 g / cc. When the rolling density of the cathode material powder is satisfied, excellent energy density can be secured, and particle breakage occurring during electrode rolling can be prevented, thereby appropriately reducing side reactions with the electrolyte, thereby improving the lifespan and stability characteristics of the battery. Meanwhile, when the positive electrode material powder is pressurized to 9 tons, the generation rate of fine particles of 1 μm or less may be 6% by volume or less, preferably, the generation rate of fine particles of 1 μm or less may be 5% by volume or less, and more preferably, the generation rate of fine particles of 1 μm or less may be 3% by volume or less. Since the surface side reaction of the positive electrode active material is mainly caused by the generation of fine particles of the positive electrode active material, if a large amount of fine particles of 1 μm or less are generated, the side reaction with the electrolyte may become severe, which may deteriorate the life characteristics and storage characteristics at high temperatures. Meanwhile, the average particle diameter (D) of the above cathode material powder 50 ) may be 2 ㎛ to 5 ㎛, preferably 2.5 ㎛ to 4.5 ㎛, more preferably 3 ㎛ to 4 ㎛, and even more preferably 3.3 ㎛ to 3.7 ㎛. The average particle diameter (D of the positive electrode powder 50 ) is the particle size when the volume accumulation amount is 50% as shown in the volume accumulation particle size distribution measured using the laser diffraction method of the positive electrode powder. At this time, the average particle diameter (D) of the positive electrode powder 50 ) If the above range is satisfied, the initial capacity and output characteristics of the battery may be excellent. Method for manufacturing cathode material powder Next, a method for manufacturing a cathode material powder according to the present invention will be described. A method for manufacturing a cathode material powder according to the present invention comprises: (S1) a step of first firing a cathode active material precursor and a lithium source after mixing them; and (S2) a step of second firing the first fired sintered product, wherein the first firing step is performed at 850°C to 960°C for 10 to 20 hours, and the second firing step sequentially includes a first holding section maintained at 720°C to 850°C, a second holding section maintained at 900°C to 970°C, and a third holding section maintained at 720°C to 850°C, wherein the cathode active material precursor has a nickel content of 80 mol% or more among all metals excluding lithium. The cathode material powder according to the present invention described above can be manufactured by appropriately controlling the type of raw material, mixing ratio, firing stage, firing temperature, firing atmosphere, etc. Hereinafter, each step of the present invention will be described in detail. ((S1) step) This is a first firing step after mixing a positive electrode active material precursor and a lithium source, and the first firing step is performed at 850°C to 960°C for 10 to 20 hours. The above-described positive electrode active material precursor is a transition metal precursor having a nickel content of 80 mol% or more among the total metals excluding lithium. Preferably, the nickel content of the total metals excluding lithium may be 82 mol% or more, and more preferably, the nickel content of the total metals excluding lithium may be 85 mol% or more. When the nickel content of the total metals excluding lithium in the positive electrode active material precursor is less than 80 mol%, a high amount of heat is required to secure crystallinity as the nickel content decreases or the content of other elements increases, and therefore, a high firing temperature is essential to increase the degree of single crystallinity. Therefore, when the nickel content of the total metals excluding lithium in the positive electrode active material precursor is less than 80 mol%, it is difficult to control the degree of single crystallinity represented by the above-described formula (1) within the aforementioned range in the firing temperature range according to the present invention, and even if the first firing step and the second firing step according to the present invention are performed to manufacture positive electrode material powder, there is a problem that it is difficult to implement excellent high-temperature storage characteristics and lifespan characteristics. In addition, the above-described positive electrode active material precursor may be purchased and used as a commercially available precursor such as nickel-cobalt-manganese hydroxide or nickel-cobalt-manganese aluminum hydroxide, or may be manufactured according to a precursor manufacturing method known in the art such as a co-precipitation method. For example, after preparing a transition metal-containing solution containing cations of nickel (Ni), cobalt (Co), and manganese (Mn), an ammonium cation-containing complex forming agent and a basic aqueous solution are added to the transition metal-containing solution to cause a coprecipitation reaction, thereby preparing a positive electrode active material precursor. If necessary, the transition metal-containing solution may further contain cations of aluminum (Al). The above transition metal-containing solution may include a nickel-containing raw material, a cobalt-containing raw material, a manganese-containing raw material, and may further include an aluminum-containing raw material as needed. The nickel-containing raw material may be, for example, a nickel-containing acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide or oxyhydroxide, and specifically, may be, but is not limited to, Ni(OH)2, NiO, NiOOH, NiCO3ㆍ2Ni(OH)2ㆍ4H2O, NiC2O2ㆍ2H2O, Ni(NO3)2ㆍ6H2O, NiSO4, NiSO4ㆍ6H2O, a fatty acid nickel salt, a nickel halide or a combination thereof. The cobalt-containing raw material may be a cobalt-containing acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide or oxyhydroxide, and specifically, may be, but is not limited to, Co(OH)2, CoOOH, Co(OCOCH3)2ㆍ4H2O, Co(NO3)2ㆍ6H2O, CoSO4, Co(SO4)2ㆍ7H2O or a combination thereof. The manganese-containing raw material may be, for example, a manganese-containing acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide, oxyhydroxide or a combination thereof, and specifically, may be, but is not limited to, manganese oxides such as Mn2O3, MnO2, Mn3O4; manganese salts such as MnCO3, Mn(NO3)2, MnSO4, manganese acetate, manganese dicarboxylic acid salts, manganese citrate, manganese fatty acid salts; manganese oxyhydroxide, manganese chloride or a combination thereof. The aluminum-containing raw material may be, but is not limited to, Al2O3, Al(OH)3, Al(NO3)3, Al2(SO4)3, (HO)2AlCH3CO2, HOAl(CH3CO2)2, Al(CH3CO2)3, aluminum halides, or combinations thereof. The transition metal-containing solution may be prepared by adding a nickel-containing raw material, a cobalt-containing raw material, a manganese-containing raw material, and an aluminum-containing raw material to a solvent, specifically, water, or a mixed solvent of an organic solvent (e.g., alcohol, etc.) that can be uniformly mixed with water, or may be prepared by mixing an aqueous solution of a nickel-containing raw material, an aqueous solution of a cobalt-containing raw material, and a manganese-containing raw material. The ammonium cation-containing complex forming agent may be, but is not limited to, NH4OH, (NH4)2SO4, NH4NO3, NH4Cl, CH3COONH4, NH4CO3, or a combination thereof. Meanwhile, the ammonium cation-containing complex forming agent may be used in the form of an aqueous solution, and in this case, the solvent may be water, or a mixture of water and an organic solvent (specifically, alcohol, etc.) that can be uniformly mixed with water. The basic compound may be a hydroxide of an alkali metal or alkaline earth metal, such as NaOH, KOH, or Ca(OH)2, a hydrate thereof, or a combination thereof. The basic compound may also be used in the form of an aqueous solution, in which case the solvent may be water, or a mixture of water and an organic solvent that is uniformly miscible with water (specifically, alcohol, etc.). The basic compound is added to adjust the pH of the reaction solution, and can be added in an amount such that the pH of the metal solution becomes 8 to 12. The co-precipitation reaction can be carried out in an inert atmosphere such as nitrogen or argon, at a temperature range of 35°C to 80°C. By the process described above, positive electrode active material precursor particles of nickel-cobalt-manganese hydroxide or nickel-cobalt-manganese-aluminum hydroxide are produced and precipitated in the reaction solution. By controlling the concentrations of the nickel-containing raw material, the cobalt-containing raw material, the manganese-containing raw material, and the aluminum-containing raw material, a positive electrode active material precursor having a nickel (Ni) content of 55 mol% or more based on the total metal content can be produced. The precipitated positive electrode active material precursor particles can be separated and dried according to a conventional method to produce a positive electrode active material precursor. The lithium raw material may include lithium-containing sulfate, nitrate, acetate, carbonate, oxalate, citrate, halide, hydroxide, or oxyhydroxide, and is not particularly limited as long as it can be dissolved in water. Specifically, the lithium raw material may be Li2CO3, LiNO3, LiNO2, LiOH, LiOHㆍH2O, LiH, LiF, LiCl, LiBr, LiI, CH3COOLi, Li2O, Li2SO4, CH3COOLi, or Li3C6H5O7, and any one of these or a mixture of two or more thereof may be used. The above mixing can be achieved through solid-state mixing or liquid-state mixing. When mixing the components through solid-state mixing, the firing process can be performed without a separate drying process. When mixing the components through liquid-state mixing, the mixed components are spray-dried before the firing process. Additionally, doping raw materials can be additionally mixed as needed. As the above doping raw material, an oxide, hydroxide, sulfide, oxyhydroxide, halide or mixture thereof containing one or more elements selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo may be used. The above first firing step can be carried out in an air or oxygen atmosphere. The above first firing step can be performed at a temperature of 850°C to 960°C, preferably 860°C to 960°C, and more preferably 870°C to 960°C. By performing the firing in the above temperature range, a cathode material powder having improved crystallinity and structural stability can be manufactured, and the area of ​​grains measured in the cross-section of an electrode manufactured by applying the cathode material powder can be adjusted to an appropriate value to have an appropriate single crystallinity. In addition, the first firing step may be performed for 10 to 20 hours, preferably 10 to 18 hours, and more preferably 10 to 15 hours. If the firing time is less than 10 hours, the crystallinity is poor, resulting in a decrease in structural stability, and particle growth is insufficient, resulting in a low degree of single crystallinity. In addition, if the firing time exceeds 20 hours, the battery output characteristics are deteriorated due to over-firing. ((S2) step) A step of secondarily firing the first fired product is included, and the second firing step sequentially includes a first holding section maintained at 720°C to 850°C, a second holding section maintained at 900°C to 970°C, and a third holding section maintained at 720°C to 850°C. The firing may be performed in an air or oxygen atmosphere. The above-described second sintering step can appropriately control the degree of single crystallinity of the cathode material powder by including a second holding section maintained at a higher temperature than the first holding section and the third holding section. Specifically, by including a second holding section in which heat treatment is performed for a short time at a higher temperature than the first holding section and the third holding section, the degree of single crystallinity of particles whose particle growth is uneven due to insufficient heat amount can be increased, thereby manufacturing cathode material powder having an appropriate degree of single crystallinity. In addition, if the first to third holding sections are included during the first sintering step rather than the second sintering step, it may be difficult to obtain an appropriate degree of single crystallinity. The temperatures of the first and third maintenance sections may each independently be 720°C to 850°C, preferably 730°C to 840°C, and more preferably 750°C to 830°C, and the temperatures of the first and third maintenance sections may be the same. When the above ranges are satisfied, the surface structure stability is excellent, so that the high-temperature lifespan and high-temperature storage performance can be improved, and particle agglomeration is reduced, so that the capacity characteristics, output characteristics, and high-temperature lifespan characteristics of the battery can be improved. The temperature of the second maintenance section may be 900°C to 970°C, preferably 910°C to 960°C, and more preferably 920°C to 950°C. When the above range is satisfied, particles can be grown with sufficient heat, so that uneven particle growth due to low heat can be improved, thereby improving the high-temperature life characteristics and high-temperature storage characteristics of the battery. The above first maintenance period may be maintained for 5 to 10 hours, preferably 6 to 10 hours, and more preferably 7 to 9 hours. When the above range is satisfied, particles can be aggregated in an appropriate number, thereby satisfying the desired single crystallinity range. The second holding period may be maintained for 5 to 60 minutes, preferably 10 to 50 minutes, and more preferably 10 to 40 minutes. When the above range is satisfied, non-uniform grain growth can be improved, thereby satisfying an appropriate single crystallinity range. The above third maintenance period may be maintained for 5 to 10 hours, preferably 6 to 10 hours, and more preferably 7 to 9 hours. When the above range is satisfied, the particles can be aggregated into an appropriate number, thereby satisfying the desired single crystallinity range. The total firing time of the above secondary firing step may be 10 to 15 hours, preferably 10 to 14 hours, and more preferably 10 to 13 hours. When the above range is satisfied, the surface structure is sufficiently stabilized, thereby improving the surface structure durability, and the particles do not excessively aggregate with each other, thereby improving the electrochemical characteristics of the battery. If necessary, the fired product that has completed the second firing step and the coating raw material can be mixed and heat-treated to form a coating layer. The above coating layer can be formed using a method known in the art, for example, a wet coating method, a dry coating method, a plasma coating method, or ALD (Atomic Layer Deposition). The above wet coating method can be performed, for example, by adding an appropriate solvent such as ethanol, water, methanol, acetone, etc. to the fired product and the coating raw material that have completed the second firing step, and then mixing them until the solvent disappears. The above dry coating method is a method of mixing a lithium composite transition metal oxide and a coating raw material in a solid state without a solvent, and for example, a grinder mixing method or a mechanofusion method can be used. The above coating raw material may be an oxide, hydroxide, oxyhydroxide, carbonate, sulfate, halide, sulfide, acetate, carboxylate or a combination thereof containing one or more elements selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Zr, Sr, W, Ta, Nb, and Mo. anode Next, the anode according to the present invention will be described. The positive electrode according to the present invention comprises a positive electrode active material layer comprising the positive electrode material powder according to the present invention. Specifically, the positive electrode comprises a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, and comprising the positive electrode material powder. Since the positive electrode material powder has been described above, a description thereof will be omitted, and components other than the positive electrode material powder will be described below. In the above positive electrode, 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 ㎛, 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, it may be used in various forms such as a film, sheet, foil, net, porous body, foam, or non-woven fabric. In addition, the positive electrode active material layer may include a conductive material and a binder together with the positive electrode material powder described above. 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 particular limitation. 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, thermal black, carbon fiber, and carbon nanotube; metal powder or metal fiber such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and 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 typically be included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the positive electrode active material layer. The above binder serves to improve adhesion between positive electrode active material particles and adhesion between the positive electrode active material and the positive electrode 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, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer rubber (EPDM rubber), sulfonated-EPDM, styrene butadiene rubber (SBR), fluororubber, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof. The above binder may be included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the positive electrode active material layer. The above positive electrode can be manufactured according to a conventional positive electrode manufacturing method. For example, the positive electrode can be manufactured by mixing a positive electrode material, a binder, and / or a conductive material in a solvent to manufacture a positive electrode slurry, applying the positive electrode slurry onto a positive electrode current collector, and then 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. Alternatively, the positive electrode may be manufactured by casting the positive electrode slurry onto a separate support, then peeling the film from the support and laminating the resulting film onto a positive electrode current collector. lithium secondary battery Next, a lithium secondary battery according to the present invention will be described. The lithium secondary battery of the present invention includes the positive electrode according to the present invention, and more specifically, includes the positive electrode including the positive electrode material powder according to the present invention. Specifically, the lithium secondary battery may include the positive electrode, the negative electrode, the separator, and the electrolyte, and more specifically, the lithium secondary battery includes the positive electrode, the negative electrode positioned opposite the positive electrode, the separator interposed between the positive electrode and the negative electrode, and the electrolyte, and the positive electrode is as described above. 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. (cathode) 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), metal oxides capable of doping and dedoping lithium, such as SnO2, vanadium oxide, and lithium vanadium oxide; or composites containing the above metal 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 active material. In addition, both low-crystalline carbon and high-crystalline carbon may be used as the carbon material. Representative examples of low-crystalline carbon include soft carbon and hard carbon, and representative examples of high-crystalline carbon include amorphous, plate-like, flaky, spherical or fibrous natural or artificial graphite, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, mesophase pitches, and high-temperature calcined carbon such as petroleum or coal tar pitch derived cokes. 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 particular limitation. 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, thermal black, carbon fiber, and carbon nanotube; metal powder or metal fiber such as copper, nickel, aluminum, and silver; conductive whiskers such as zinc oxide and 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 typically be included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the negative electrode active material layer. The above binder serves to improve adhesion between negative electrode active material particles and adhesion between the negative electrode active material and the negative electrode 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, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer rubber (EPDM rubber), sulfonated-EPDM, styrene-butadiene rubber (SBR), fluororubber, or various copolymers thereof, and one of these may be used alone or a mixture of two or more thereof may be used. The above binder may be included in an amount of 1 to 30 wt%, preferably 1 to 20 wt%, and more preferably 1 to 10 wt%, based on the total weight of the negative electrode active material layer. The above-described negative electrode active material layer may be manufactured by, for example, applying a negative electrode slurry containing a negative electrode active material and optionally a binder and a conductive material onto a negative electrode current collector and drying it, or by casting the negative electrode slurry onto a separate support and then laminating the resulting film onto a negative electrode current collector by peeling it off from the support. (Separator) 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 retention 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 may be used to secure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure. (electrolyte) 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. The organic solvent may be used without any particular limitation as long as it can serve as a medium through which ions involved in the electrochemical reaction of the battery can move. Specifically, the organic solvent may include 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), methylethylcarbonate (MEC), ethylmethylcarbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); alcohol solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (wherein R is a C2 to C20 linear, branched, or cyclic hydrocarbon group, and may include a double-bonded aromatic ring or an ether bond); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane; or sulfolanes can be used. Among these, a carbonate solvent is preferable, and a mixture of a cyclic carbonate (e.g., ethylene carbonate or propylene carbonate, etc.) having high ionic conductivity and high dielectric constant that can improve the charge / discharge performance of the battery and a linear carbonate compound having low viscosity (e.g., ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate, etc.) is more preferable. 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. The concentration of the lithium salt is preferably within the range of 0.1 to 5.0 M, preferably 0.1 to 3.0 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 additives for the purpose of improving the life characteristics of the battery, suppressing battery capacity decrease, and improving the discharge capacity of the battery. For example, the additives may include haloalkylene carbonate compounds such as difluoroethylene carbonate, pyridine, triethylphosphite, triethanolamine, cyclic ethers, ethylene diamine, n-glyme, hexamethylphosphoric 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, either singly or in mixtures, but are not limited thereto. The additives may be included in an amount of 0.1 to 10 wt%, preferably 0.1 to 5 wt%, based on the total weight of the electrolyte. As described above, a lithium secondary battery including a cathode material powder according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate, 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. Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. Example 1 Nickel-cobalt-manganese-aluminum hydroxide powder having a molar ratio of Ni:Co:Mn:Al of 85:7:6:2 and lithium hydroxide were mixed so that the molar ratio of transition metal (Ni+Co+Mn+Al):Li was 1:1.04, and then a first calcination step was performed by calcining at 950°C for 12 hours. After that, a second firing step was performed sequentially to manufacture a cathode powder by performing a first holding section in which the first fired product was maintained at 820°C for 5 hours, a second holding section in which the product was maintained at 950°C for 10 minutes, and a third holding section in which the product was maintained at 820°C for 5 hours. Example 2 A cathode material powder was manufactured in the same manner as in Example 1, except that the first firing step was performed at 870°C for 12 hours, the first holding section was performed at 805°C for 5 hours, the second holding section was performed at 950°C for 10 minutes, and the third holding section was performed at 805°C for 5 hours in sequence. Comparative Example 1 A nickel-cobalt-manganese-aluminum hydroxide powder having a molar ratio of Ni:Co:Mn:Al of 85:7:6:2 and lithium hydroxide were mixed so that the molar ratio of transition metal (Ni+Co+Mn+Al):Li was 1:1.04, and then a first calcination step of calcining at 830°C for 22 hours was performed to manufacture a cathode material powder. Comparative Example 2 A cathode material powder was manufactured in the same manner as in Comparative Example 1, except that a first firing step of firing at 950°C for 20 hours was performed. Comparative Example 3 Nickel-cobalt-manganese-aluminum hydroxide powder having a molar ratio of Ni:Co:Mn:Al of 85:7:6:2 and lithium hydroxide were mixed so that the molar ratio of transition metal (Ni+Co+Mn+Al):Li was 1:1.04, and then a first calcination step of calcining at 950°C for 8 hours was performed, followed by calcination at 800°C for 8 hours to manufacture cathode material powder. Comparative Example 4 A cathode material powder was manufactured in the same manner as in Comparative Example 3, except that a first firing step of firing at 965°C for 10 hours was performed, followed by firing at 860°C for 10 hours. Comparative Example 5 Nickel-cobalt-manganese-aluminum hydroxide powder having a molar ratio of Ni:Co:Mn:Al of 85:7:6:2 and lithium hydroxide having a molar ratio of transition metal (Ni+Co+Mn+Al):Li of 1:1.04 were mixed, and then calcined at 920°C for 8 hours, 950°C for 10 minutes, and 920°C for 8 hours to manufacture cathode powder. Comparative Example 6 A cathode material powder was manufactured in the same manner as in Example 1, except that the first firing step was performed at 950°C for 12 hours, the first holding section was performed at 820°C for 5 hours, the second holding section was performed at 990°C for 5 minutes, and the third holding section was performed at 820°C for 5 hours in sequence. Comparative Example 7 A cathode material powder was manufactured in the same manner as in Example 1, except that the first firing step was performed at 950°C for 12 hours, the first holding section was performed at 820°C for 5 hours, the second holding section was performed at 890°C for 20 minutes, and the third holding section was performed at 820°C for 5 hours in sequence. Comparative Example 8 A cathode material powder was manufactured in the same manner as in Example 1, except that nickel-cobalt-manganese-aluminum hydroxide powder having a molar ratio of Ni:Co:Mn:Al of 75:5:18:2 and lithium hydroxide were mixed so that the molar ratio of transition metal (Ni+Co+Mn+Al):Li was 1:1.04. The manufacturing methods of Examples 1 to 2 and Comparative Examples 1 to 8 are summarized and shown in Table 1 below. Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Firing Recurrence 2 times 2 times 1 time 1 time 2 times 2 times 1 time 2 times 2 times Firing Temperature and Time1st 950℃ / 12h870℃ / 12h830℃ / 22h950℃ / 20h950℃ / 8h965℃ / 10h920℃ / 8h950℃ / 12h950℃ / 12h950℃ / 12h950℃ / 10min920℃ / 8h2nd 820℃ / 5h805℃ / 5h--80 0℃ / 8h860℃ / 10h-820℃ / 5h820℃ / 5h820℃ / 5h950℃ / 10min950℃ / 10min990℃ / 5min890℃ / 20min950℃ / 10min820℃ / 5h805℃ / 5h820℃ / 5h820℃ / 5h820℃ / 5h Experimental Example 1: Measurement of average particle diameter, BET specific surface area, particle breakage, and rolling density. (Average particle diameter (D 50 ) measurement) After dispersing 0.03 g of each cathode material powder manufactured in Examples 1 to 2 and Comparative Examples 1 to 8 in a dispersion medium, it was introduced into a laser diffraction particle size measuring device (Microtrac MT 3000) and irradiated with ultrasonic waves of about 28 kHz at an output of 60 W to determine the average particle diameter (D) of each cathode material powder. 50 ) was measured. The measurement results are shown in Table 2 below. (BET surface area measurement) In addition, 3 g of the cathode material powder manufactured according to Examples 1 to 2 and Comparative Examples 1 to 8 was collected and measured using the BET method using BELSORP-mini II, and the measurement results are shown in Table 2 below. (Particle breakage measurement) In addition, 5 g of the cathode material powders manufactured according to Examples 1 to 2 and Comparative Examples 1 to 8 were placed in a cylindrical metal mold with a diameter of 4 cm, pressed with a pressure of 9 tons, and the volume cumulative particle size distribution (PSD) was measured to determine the rate of generation of fine particles with a particle size of 1 μm or less. The rate of generation of fine particles with a particle size of 1 μm or less was converted to volume% with respect to the total volume of the cathode material powder and is shown in Table 2. (Rolling density measurement) In addition, the rolling density was measured using HANTECH HLP-AC12-T. Specifically, 5 g of the cathode material powders manufactured according to Examples 1 to 2 and Comparative Examples 1 to 8 were placed in a cylindrical metal mold with a diameter of 4 cm, pressed under a pressure of 2 tons, and the height of the pressed mold was measured using a vernier caliper to obtain the rolling density, which is shown in Table 2. Experimental Example 2: EBSD Analysis and Single Crystallinity Measurement An electrode slurry was prepared by mixing the positive electrode powders manufactured in Examples 1 to 2 and Comparative Examples 1 to 8, carbon black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder in a weight ratio of 95:2.5:2.5 in N-methylpyrrolidone (NMP). The electrode slurry was applied to one surface of an aluminum current collector and then dried at 130°C to prepare an electrode for EBSD analysis. Rolling was not performed during the manufacture of the positive electrode. The anode was cross-sectioned using an ion milling device (HITACHI IM-500, accelerating voltage 6 kV), and an SEM image was obtained using a FE-SEM (JEOL JSM7900F) equipped with a backscatter electron diffraction pattern analyzer (EBSD), and an EBSD analysis was performed using the SEM image. The EBSD analysis was performed at an accelerating voltage of 15 kV, a WD of 15 mm, and a scale with a total number of grains of approximately 400+ / -10. The area of ​​each grain observed in each anode cross-section was measured through EBSD analysis, and the degree of single crystallinity was calculated by substituting it into Equation (1). The measurement results are shown in Table 2 below. In addition, FIGS. 1 to 3 show SEM images of electrode cross-sections manufactured using the positive electrode powders of Examples 1 to 2 and Comparative Example 2, and FIGS. 4 to 6 show EBSD analysis images of electrode cross-sections manufactured using the positive electrode powders of Examples 1 to 2 and Comparative Example 2. Nickel molar ratio particle form D among all metals except lithium in oxide 50 (㎛) specific surface area (m 2 / g) Particle Breakage (vol%) Rolled Density (g / cc) Single Crystallinity Example 10.85 Single particle or pseudo-single particle 3.5 10.5 3 1.6 5 3.0 5 2.4 5 Example 20.85 Single particle or pseudo-single particle 3.5 6 0.6 8 2.8 8 2.9 8 2.0 4 Comparative Example 10.85 2 Single particle 3.4 5 1.1 2 12.1 3 2.6 3 Comparative Example 20.85 Single particle or pseudo-single particle 3.5 4 0.7 7 2 7 2.8 4 1.6 7 Comparative Example 30.85 Single particle or pseudo-single particle 3.2 4 0.7 4 0.3 6 2.8 8 1.7 8 Comparative Example 40.85 Single particle or Pseudo-single particle 4.0 10.4 5 0.12 3.1 13.21 Comparative example 50.85 Single particle or pseudo-single particle 3.4 7 0.8 0 7.6 12.7 9 1.62 Comparative example 60.85 Single particle or pseudo-single particle 4.0 5 0.4 7 0.11 3.13 3.24 Comparative example 70.85 Single particle or pseudo-single particle 3.2 8 0.7 16.5 5 2.9 2 1.81 Comparative example 80.75 Single particle or pseudo-single particle 2.8 1.0 15.8 2.4 5 1.1 As can be confirmed in Table 2 above, in the case of Examples 1 to 2, it can be seen that the single crystallinity range described above is satisfied compared to Comparative Examples 1 to 8. <Lithium secondary battery manufacturing> The cathode material powders manufactured in Examples 1 to 2 and Comparative Examples 1 to 8, respectively, carbon black as a conductive material, and polyvinylidene fluoride (PVDF) as a binder were mixed in a weight ratio of 95:2.5:2.5 in N-methyl-2-pyrrolidone (NMP) to manufacture a cathode slurry. The cathode slurry was applied to one surface of an aluminum current collector, dried at 130°C, and then rolled to manufacture a cathode. A negative electrode slurry was prepared by mixing artificial graphite as a negative active material, carbon black as a conductive material, and SBR-CMC as a binder in a weight ratio of 95:3.5:1.5, and the slurry was applied to one side of a copper current collector, dried at 100°C, and then rolled to produce a negative electrode. An electrode assembly was manufactured by interposing a separator between the positive and negative electrodes, and then positioning it inside a battery case, and then injecting an electrolyte into the case to manufacture a lithium secondary battery. The electrolyte was an electrolyte in which 1 M LiPF6 was dissolved in a mixed organic solvent of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a volume ratio of 1:2. Experimental Example 3: Evaluation of High-Temperature Storage Characteristics Each of the lithium secondary batteries manufactured above was charged in CC-CV mode at 0.5C until the voltage reached 4.2 V, and then the secondary batteries were disassembled to separate the positive electrodes. Then, the positive electrodes and 200 μL of electrolyte were placed in a pouch-type battery case and sealed to manufacture cells. The cells were stored at 65°C for 8 weeks, and the cell volume change (ΔCell volume, unit: ΔmL) before and after high-temperature storage was measured. The cell volume change was measured by placing the cell in water and measuring the volume change of the water. The measurement results are shown in Table 3. Experimental Example 4: Evaluation of High-Temperature Lifetime Characteristics For each lithium secondary battery manufactured above, 100 charge-discharge cycles were performed, in which one cycle was defined as charging to 4.2 V at 1 C in CC-CV mode at 45°C and discharging to 2.5 V at a constant current of 2 C, and then the capacity retention rate was measured to evaluate the high-temperature life characteristics. The measurement results are shown in Table 3. Cell volume change (ΔmL) after 8 weeks of high temperature storage Capacity retention rate (%) Example 10.2597.8 Example 20.3995.4 Comparative example 10.7888.1 Comparative example 20.4892.6 Comparative example 30.4393.5 Comparative example 40.2290.3 Comparative example 50.5191.3 Comparative example 60.2188.8 Comparative example 70.4193.9 Comparative example 80.9784.2 Through the above Table 3, it can be confirmed that the batteries using the cathode powders of Examples 1 to 2, in which the single crystallinity of Equation (1) satisfies the scope of the present invention, have superior high-temperature life characteristics and high-temperature storage characteristics compared to the batteries using the cathode powders of Comparative Examples 1 to 8.

Claims

1. Containing lithium nickel oxide particles represented by the following chemical formula 1, A cathode material powder having a single crystallinity of 1.85 to 3.00, represented by the following formula (1): [Chemical Formula 1] Li a Ni b Co c M 1 d M 2 e O2 In the above chemical formula 1, M 1 is Mn, Al or a combination thereof, and M 2 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.80≤a≤1.20, 0.80≤b<1, 0 <c<0.45, 0<d<0.45, 0≤e≤0.20이다: Equation (1): Single crystallinity = In the above equation (1), A k is the area of ​​the kth grain measured when an electrode manufactured by applying the above cathode material powder is subjected to ion milling treatment and then the electrode cross-section is analyzed by backscatter electron diffraction (EBSD), and n is the total number of grains measured through the backscatter electron diffraction (EBSD) analysis and is 200 to 500.

2. In paragraph 1, The above chemical formula 1 is a cathode material powder represented by the following chemical formula 1-1: [Chemical Formula 1-1] Li a1 Ni b1 Co c1 Mr d1 Al d2 M 2 e1 O2 In the above chemical formula 1-1, M 2 is at least one selected from the group consisting of Ti, Mg, Al, Zr, Y, Ba, Ca, Sr, W, Ta, Nb, and Mo, and 0.85≤a1≤1.20, 0.80≤b1<1, 0 <c1<0.18, 0<d1<0.18, 0<d2<0.15, 0≤e1≤0.20, 0<d1+d2<0.33이다.

3. In paragraph 1, The specific surface area of ​​the above cathode powder is 0.40 m 2 / g to 0.75m 2 / g of cathode material powder.

4. In paragraph 1, The above cathode material powder has a rolling density of 2.9 g / cc to 3.2 g / cc.

5. In paragraph 1, A cathode material powder having a particle size generation rate of 1㎛ or less of 6% by volume or less when the cathode material powder is pressurized to 9 tons.

6. In paragraph 1, The average particle diameter (D) of the above cathode material powder 50 ) A cathode material powder having a size of 2㎛ to 5㎛.

7. In paragraph 1, The above cathode material powder is a cathode material powder having a single crystallinity of 2.0 to 2.5, as represented by Equation (1). 8.(S1) A step of mixing a positive electrode active material precursor and a lithium source and then performing a first calcination; and (S2) comprising a step of secondarily firing the first fired product, The above first firing step is performed at 850°C to 960°C for 10 to 20 hours, The above second firing step sequentially includes a first holding section maintained at 720°C to 850°C, a second holding section maintained at 900°C to 970°C, and a third holding section maintained at 720°C to 850°C. A method for manufacturing the positive electrode powder of claim 1, wherein the positive electrode active material precursor has a nickel content of 80 mol% or more among all metals excluding lithium.

9. In paragraph 8, A method for manufacturing the cathode material powder of claim 1, wherein the first firing step is performed at 870°C to 960°C for 10 to 15 hours.

10. In paragraph 8, A method for manufacturing the positive electrode powder of claim 1, wherein the first maintenance section and the third maintenance section are each independently maintained for 5 to 10 hours.

11. In paragraph 8, A method for manufacturing the positive electrode powder of claim 1, wherein the second maintenance section is maintained for 5 to 60 minutes.

12. In paragraph 8, A method for manufacturing the cathode material powder of claim 1, wherein the total firing time of the second firing step is 10 to 15 hours.

13. A cathode comprising the cathode material powder of claim 1; cathode; membrane; and A lithium secondary battery comprising an electrolyte.

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