Positive electrode and lithium secondary battery comprising same

Abstract

The present invention relates to a positive electrode and a lithium secondary battery comprising same, the positive electrode: comprising a positive electrode material comprising a lithium nickel-based oxide which is in the form of a single particle and comprises Y and Zr; and having a preferred orientation index according to expression 1 of 1.2 to 1.8.

Description

Anode and lithium secondary battery containing the same This application claims the benefit of priority to Korean Patent Application No. 10-2023-0156383, filed November 13, 2023, and Korean Patent Application No. 10-2024-0160276, filed November 12, 2024, the entire contents of which are incorporated herein by reference. The present invention relates to a cathode including a single particle type cathode material and having a controlled preferential orientation index, and a lithium secondary battery including the cathode. Lithium secondary batteries are 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 intercalation and deintercalation of lithium ions. Among these, lithium nickel oxides containing two or more transition metals have been developed to complement the problems of lithium nickel oxides containing only Ni, Co, or Mn as cathode materials, and among these, lithium nickel cobalt manganese oxides containing Ni, Co, and Mn are widely used in the field of electric vehicle batteries. Conventional lithium nickel cobalt manganese oxides are usually in the form of spherical secondary particles in which tens to hundreds of primary particles are aggregated. However, when lithium nickel cobalt manganese oxides in the form of secondary particles in which many primary particles are aggregated are applied, there is a problem in that the primary particles are likely to fall off during the rolling process during the manufacture of the positive electrode, and cracks occur inside the particles during the charge and discharge process. When the positive electrode material is broken or cracked, the contact area with the electrolyte increases, which increases gas generation and positive electrode material deterioration due to side reactions with the electrolyte, and this reduces the life characteristics. In order to solve the above problems, a technology has been proposed to manufacture a cathode material in the form of a single particle rather than a secondary particle by increasing the sintering temperature during the manufacture of lithium nickel cobalt manganese oxide. A cathode material in the form of a single particle has a smaller contact area with the electrolyte than a conventional cathode material in the form of a secondary particle, so it has less side reactions with the electrolyte, and has excellent particle strength, so it has the advantage of less particle breakage during electrode manufacture. Therefore, when a cathode material in the form of a single particle is applied, the high-temperature performance of the battery can be improved. However, a conventional cathode material in the form of a single particle has high resistance, so when it is applied, there is a limitation that the output characteristics are reduced. The present invention provides a cathode having a controlled preferred orientation by including a cathode material having a controlled particle shape and doping element, thereby simultaneously improving the high-temperature life and output characteristics of a lithium secondary battery. [1] The present invention provides a cathode including a cathode material including a single-particle lithium nickel-based oxide including Y and Zr, and having a preferred orientation index of 1.2 or more and 1.8 or less according to the following formula 1. [Formula 1] In the above equation 1, I(003) / I(104) is the ratio of the peak intensity I(003) of the (003) plane to the peak intensity I(104) of the (104) plane obtained by XRD analysis of the above cathode material. I'(003) / I'(104) is the ratio of the peak intensity I'(003) of the (003) plane to the peak intensity I'(104) of the (104) plane obtained by XRD analysis of the above anode. [2] The present invention provides a cathode having a single particle magnetization degree of 2.0 or more and 4.5 or less according to the following formula 2 of the cathode material in the above [1]. [Formula 2] In the above equation 2, R i is the radius of the i-th grain measured when the electrode manufactured by applying the above cathode material is subjected to ion milling treatment and then analyzed by backscatter electron diffraction (EBSD). Although it is a value measured in μm, the value substituted into Equation 2 is a unitless number that does not include a unit. n is the total number of grains measured through the above EBSD analysis, which is 350 to 450. [3] The present invention, in the above [1] or [2], D of the positive electrode material 50 This provides a cathode having a diameter of 1.0 μm to 6.0 μm. [4] The present invention provides a positive electrode, wherein Y is included in an amount of 200 ppm to 800 ppm based on the total weight of the lithium nickel-based oxide, in at least one of the above [1] to [3]. [5] The present invention provides a positive electrode, wherein, in at least one of the above [1] to [4], the Zr is contained in an amount of 1,000 ppm to 3,000 ppm based on the total weight of the lithium nickel-based oxide. [6] The present invention provides a positive electrode, wherein the lithium nickel-based oxide has a composition represented by the following chemical formula 1, in at least one of the above [1] to [5]. [Chemical Formula 1] Li a Ni 1-x-y Co x M1 y M2 w O 2 In the above chemical formula 1, 1.0≤a≤1.5, 0≤x≤0.2, 0≤y≤0.2, 0 <w≤0.1, 0<x+y≤0.2이고, M1 is at least one selected from the group consisting of Mn and Al, M2 is two or more elements selected from the group consisting of Y, Zr, Ba, Ca, Ti, Mg, Ta, Nb, and Mo, but Y and Zr are necessarily included. [7] The present invention provides an anode in which I(003) / I(104) of the formula 1 is 1.0 to 1.6 in at least one of the above [1] to [6]. [8] The present invention provides an anode in which I'(003) / I'(104) of the formula 1 is 1.2 to 2.9 in at least one of the above [1] to [7]. [9] The present invention provides a positive electrode, wherein in at least one of the above [1] to [8], the positive electrode comprises a positive electrode current collector; and a positive electrode mixture layer provided on the positive electrode current collector and including the positive electrode material, wherein the positive electrode mixture layer has a porosity of 10% to 32%.

[0010] The present invention provides a lithium secondary battery comprising at least one of the positive electrodes [1] to [9]; a negative electrode including a negative electrode active material; a separator interposed between the positive electrode and the negative electrode; and an electrolyte. According to one embodiment of the present invention, a cathode includes a single particle-type lithium nickel-based oxide having superior particle strength compared to secondary particles as a cathode material, and therefore can withstand strong rolling conditions during the manufacturing process, and thus has the advantage of superior energy density per unit volume. In addition, since the amount of fine particles generated due to particle breakage of the positive electrode material is small, a battery using the positive electrode has an excellent lifespan at high temperatures. In addition, the cathode material has a high nickel content, so it has excellent capacity and can reduce the amount of cobalt used, so it is advantageous in terms of material supply and price. In addition, since the cathode material has a high degree of single particle magnetization and a controlled preferential orientation, an electrode including the cathode material exhibits high ionic conductivity, which can contribute to improving the output characteristics of a battery. Figure 1 is a diagram showing an SEM image of the cathode material powder manufactured in Example 1. Figure 2 is a diagram showing an SEM image of the cathode material powder manufactured in Example 2. Figure 3 is a diagram showing an SEM image of the cathode material powder manufactured in Comparative Example 1. Figure 4 is a diagram showing an SEM image of the cathode material powder manufactured in Comparative Example 2. Figure 5 is a diagram showing an SEM image of the cathode material powder manufactured in Comparative Example 3. Figure 6 is a diagram showing an SEM image of the cathode material powder manufactured in Comparative Example 4. Figure 7 is a diagram showing an SEM image of the cathode material powder manufactured in Comparative Example 5. Figure 8 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Example 1. Figure 9 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Example 2. Figure 10 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Comparative Example 1. Figure 11 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Comparative Example 2. Figure 12 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Comparative Example 3. Figure 13 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Comparative Example 4. Figure 14 is a diagram showing an EBSD map of a cross-section of an electrode manufactured using the cathode material powder of Comparative Example 5. Hereinafter, the present invention will be described in more detail to help understand the present invention. In the present invention, “single particle type” means a particle composed of 30 or fewer nodules, and is a concept that includes a single particle composed of one nodule and a pseudo-single particle that is a composite of 2 to 30 nodules. The above "nodule" is a sub-particle unit that constitutes a single particle and a quasi-single particle, and may be a single crystal without a crystalline grain boundary, or a polycrystal that has no apparent grain boundary when observed under a field of view of 5,000 to 20,000 times using a scanning electron microscope. In the present invention, "secondary particle" means 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 agglomerate of more than 30 primary particles. In the present invention, “particle” is a concept including any one or all of a single particle, a quasi-single particle, a primary particle, a nodule, and a secondary particle. In the present invention, "D 50 " refers to the particle size corresponding to 50% of the volume accumulation in the volume accumulation particle size distribution of the corresponding particle powder, and can be measured using the laser diffraction method. For example, after dispersing the cathode material powder in a dispersion medium, it can be measured by introducing it into a commercially available laser diffraction particle size measuring device (e.g., S-3500 from Microtrac), irradiating it with ultrasonic waves of about 28 kHz with an output of 60 W, obtaining a volume accumulation particle size distribution graph, and then finding the particle size at the point where the volume accumulation amount is 50% in the obtained volume accumulation particle size distribution graph. 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 a backscatter electron diffraction (EBSD) map image. The size of the grain can be measured by image analysis of the EBSD map. In the present invention, "X-ray diffraction analysis (XRD)" was performed by irradiating a measurement target sample with X-rays and analyzing a diffraction grating. Specifically, the measurement target sample was fixed to a holder, and then X-ray diffraction analysis was performed under the conditions of FDS 0.5°, 2θ = 10° to 90°, step size 0.014 degree, and total scan time of approximately 40 minutes using a Bruker D8 Endeavor (light source: Cu Kα, λ = 1.54Å) equipped with a LynxEye XE-T position sensitive detector. For the measured data, Rietveld refinement was performed considering the charge at each site (metal ions at the transition metal site are +3, Ni ions at the Li site are +2) and cation mixing. Instrumental broadening was considered using the Fundamental Parameter Approach (FPA) implemented in the Bruker TOPAS program, and the entire peaks of the measurement range were used for fitting. Peak shape was fitted using only Lorentzian contribution as FP (First Principle) among the peak types available in TOPAS, and strain was not considered. The cathode according to the present invention comprises a cathode material including a single particle lithium nickel-based oxide containing Y and Zr, and has a preferred orientation index according to the following equation 1 of 1.2 or more and 1.8 or less. [Formula 1] In the above equation 1, I(003) / I(104) is the ratio of the peak intensity I(003) of the (003) plane to the peak intensity I(104) of the (104) plane obtained by XRD analysis of the above cathode material. I'(003) / I'(104) is the ratio of the peak intensity I'(003) of the (003) plane to the peak intensity I'(104) of the (104) plane obtained by XRD analysis of the above anode. Since single-particle high-nickel cathode materials generally have high orientation, when producing an electrode using them, there is a limitation that the ionic conductivity, which is an indicator of output characteristics, decreases because the particles within the electrode are preferentially oriented in the same direction. However, as described above, when the cathode material contains Y (yttrium) and Zr (zirconium) as doping elements and the preferential orientation index of the cathode is adjusted within the above numerical range, this can be improved. Specifically, when a lithium nickel-based oxide containing Zr is used as a cathode material, the particle size can be increased at the same sintering temperature, and thus the crystallinity and single particle degree of the cathode material are improved, which can contribute to improving the high-temperature life of the battery. However, a cathode material with high crystallinity and single particle size increases the preferential orientation of the cathode, which means that the particles within the cathode are preferentially arranged in the same direction, which causes a decrease in the output of the battery. Herein, the inventors of the present invention doped Y together with Zr, and confirmed that this allows for appropriate control of the preferred orientation of the cathode without impairing the crystallinity and single-particle morphology of the cathode material. Y doping contributes to increasing the sphericity of the cathode material, and a cathode material with a high sphericity can lower the preferred orientation of the cathode. Specifically, when the crystallinity and single-particle morphology are high, growth in a specific direction is prominent, and particles that have grown a lot in a specific direction become oriented when subjected to force in a situation such as electrode rolling. At this time, when the sphericity is high, the particles maintain a shape close to a sphere, so that orientation in the same direction can be prevented to some extent. Therefore, the anode including such a cathode material can have the preferred orientation index, which is an index reflecting both the crystallinity of the cathode material and the preferred orientation of the cathode, adjusted to be 1.2 or more and 1.8 or less. That is, a battery including the above positive electrode can exhibit excellent output characteristics as well as life characteristics at high temperatures. Below, each component of the present invention is described in more detail. Bipolar material First, the cathode material includes a single-particle lithium nickel oxide. Specifically, the single particle magnetization degree of the above cathode material according to the following Equation 2 may be 2.0 or more and 4.5 or less. [Formula 2] In the above equation 2, R i is the radius of the i-th grain measured when the electrode manufactured by applying the above cathode material is subjected to ion milling treatment and then analyzed by backscatter electron diffraction (EBSD). Although it is a value measured in μm, the value substituted into Equation 2 is a unitless number that does not include a unit. n is the total number of grains measured through the above EBSD analysis, which is 350 to 450. Since the above cathode material includes lithium nickel-based oxide particles in the form of single particles or pseudo-single particles, it has a smaller contact area with the electrolyte than conventional lithium nickel-based oxides in the form of secondary particles, so there is less side reaction with the electrolyte, and since the particle strength is excellent, there is an advantage of less particle breakage during rolling during the cathode manufacturing process. More specifically, the cathode material may have a single particle magnetization degree of 2.5 or more, 2.8 or more, or 3.0 or more according to Equation 2 below. A higher single particle magnetization degree means that there are many particles with a small number of grains, that is, particles in the form of single particles, in the cathode material, so that there is an effect of improving high-temperature performance. However, if it exceeds 4.5, the resistance may become excessively high, which may deteriorate the output and capacity characteristics, and therefore, it may be 4.5 or less, 4.0 or less, or 3.7 or less. Meanwhile, R of the above formula 1 i The grain radius corresponding to may be 0.4 ㎛ to 2.5 ㎛, specifically 0.4 ㎛ to 2.0 ㎛, and more specifically 0.4 ㎛ to 1.0 ㎛, and the average grain diameter of the positive electrode material measured through EBSD may be 0.5 ㎛ to 4.0 ㎛, preferably 0.8 ㎛ to 2.0 ㎛, and more preferably 0.8 ㎛ to 1.8 ㎛. When the average grain diameter of the positive electrode material satisfies the above range, the rock salt phase in the lithium nickel-based oxide is reduced, so that the resistance characteristics are more excellent. In addition, D of the above cathode material 50 The diameter may be 1.0 ㎛ to 6.0 ㎛, preferably 1.0 ㎛ to 5.0 ㎛, and more preferably 2.0 ㎛ to 4.0 ㎛. For high temperature life and reduction of gas generation, D 50 It is desirable that this is 1.0㎛ or more, but D 50Considering that this small size is advantageous in terms of reducing orientation and increasing output, it is desirable to have a size of 6.0㎛ or less. Meanwhile, the lithium nickel-based oxide contains Y and Zr as doping elements. By including Y as a doping element, the effect of lowering the preferred orientation of the positive electrode can be obtained, and by including Zr, the effect of increasing the single-particle magnetization degree of the positive electrode material can be obtained. Specifically, the Y may be included in an amount of 200 ppm or more, 300 ppm or more, or 400 ppm or more based on the total weight of the lithium nickel-based oxide, and in this case, it is preferable in that the degree of sphericity can be improved and the degree of preferential orientation can be lowered. However, considering the capacity characteristics of the positive electrode material, it is preferable that it does not exceed 800 ppm. In addition, the Zr may be included in an amount of 1,000 ppm or more, 1,200 ppm or more, or 1,500 ppm or more based on the total weight of the lithium nickel-based oxide, in which case it is preferable in terms of improving the degree of single particle magnetization and controlling the degree of preferential orientation not to become too low. However, considering the capacity characteristics of the cathode material and the decrease in ion conductivity due to the high degree of preferential orientation, it is preferable that it does not exceed 3,000 ppm. Meanwhile, I(003) / I(104) of the above formula 1 may be 1.0 to 1.6, preferably 1.1 to 1.6, and more preferably 1.2 to 1.6. The I(003) / I(104) of the above formula 1 can represent the crystallinity characteristics of the positive electrode material layered structure. That is, the larger the I(003) / I(104) value, the better the layered structure grew and the less the cation mixing phenomenon between lithium ions and nickel ions. Therefore, it is preferable that the I(003) / I(104) value of the formula 1 is within the above range, in that it indicates that the layered structure grew well in the form of a single crystal. Meanwhile, according to one embodiment of the present invention, the content of nickel among the metals other than lithium in the lithium nickel-based oxide may be 70 mol% or more, preferably 80 mol% or more, more preferably 90 mol% or more, but may be 99 mol% or less. In this case, there is an advantage of being able to implement a high capacity. In addition, the lithium nickel-based oxide may have a composition represented by the following chemical formula 1. [Chemical Formula 1] Li a Ni 1-x-y Co x M1 y M2 w O 2 In the above chemical formula 1, 1.0≤a≤1.5, 0≤x≤0.2, 0≤y≤0.2, 0 <w≤0.1, 0<x+y≤0.2이고, M1 is at least one selected from the group consisting of Mn and Al, M2 is two or more elements selected from the group consisting of Y, Zr, Ba, Ca, Ti, Mg, Ta, Nb, and Mo, but Y and Zr are necessarily included. The above a represents the molar ratio of lithium in the lithium nickel-based oxide, and may be 0≤a≤0.20, or 0≤a≤0.10. When the molar ratio of lithium satisfies the above range, the crystal structure can be formed stably. The above 1-xy represents the molar ratio of nickel among the total metal excluding lithium in the lithium nickel-based oxide, and may be 0.80≤1-xy<1, 0.90≤1-xy<1, or 0.92≤1-xy<1. When the molar ratio of nickel satisfies the above range, high energy density is exhibited, enabling high capacity implementation. The above x represents the molar ratio of cobalt among the total metals excluding lithium in the lithium nickel-based oxide, and is 0. <x≤0.12, 0<x≤0.06, 또는 0<x≤0.05일 수 있다. 코발트의 몰비가 상기 범위를 만족할 때, 양호한 저항 특성 및 출력 특성을 구현할 수 있다. The above y represents the molar ratio of M1 among the total metals excluding lithium in the lithium nickel oxide, and is 0. <y≤0.08, 0<y≤0.04, 또는 0<y≤0.03일 수 있다. 망간의 몰비가 상기 범위를 만족할 때, 양극재의 구조 안정성이 우수하게 나타난다. The above w represents the molar ratio of M2 among the total metals excluding lithium in the lithium nickel oxide, and the above d is 0. <w≤0.08, 0<w≤0.05, 또는 0<w≤0.03일 수 있다. Meanwhile, the lithium nickel-based oxide can be manufactured by mixing a precursor and a lithium raw material and then calcining. At this time, the precursor can be purchased and used as a commercially available precursor, or can be manufactured according to a precursor manufacturing method known in the art. For example, the precursor can be manufactured by introducing a transition metal aqueous solution, an ammonium cation complex forming agent, and a basic compound into a reactor and performing a co-precipitation reaction while stirring. The above transition metal aqueous solution can be prepared by dissolving a transition metal-containing raw material in a solvent such as water, and for example, it can be prepared by dissolving a nickel-containing raw material, a cobalt-containing raw material, a manganese-containing raw material, an aluminum-containing raw material, a yttrium-containing raw material, a zirconium-containing raw material, etc. in water. Meanwhile, the above transition metal-containing raw material may be an acetate, carbonate, nitrate, sulfate, halite, sulfide or oxide of the transition metal. Specifically, the nickel-containing raw material is, for example, NiO, NiCO. 3·2Ni(OH) 2 ·4H 2 O, NiC 2 O 2 ·2H 2 O, Ni(NO 3 ) 2 ·6H 2 O, NiSO 4 , NiSO 4 ·6H 2 O, nickel halide or a combination thereof. The above cobalt-containing raw material is, for example, CoSO 4, Co(OCOCH 3 ) 2 ㆍ4H 2 O, Co(NO 3 ) 2 ㆍ6H 2 O, CoSO 4 ㆍ7H 2 O or a combination of these. The above manganese-containing raw material is, for example, Mn 2 O 3 , MnO 2 , Mn 3 O 4 , MnCO 3 , Mn(NO 3 ) 2 , MnSO 4 ㆍH 2 O, manganese acetate, manganese halide, or a combination thereof. The above aluminum-containing raw material is, for example, Al 2 O 3 , Al(OH) 3 , Al(NO 3 ) 3 , Al 2 (SO 4 ) 3 , (HO) 2 AlCH 3 CO 2 , HOAl(CH 3 CO 2 ) 2 , Al(CH 3 CO 2 ) 3, aluminum halides or combinations thereof. The above yttrium-containing raw material is, for example, Y 2 O 3 , Y(NO 3 ) 3 ㆍ6H 2 O, YCl 3 ㆍ6H 2 O or a combination of these. The above zirconium-containing raw material is, for example, ZrO 2 , ZrCl 4 , Zr(OH) 4 , Zr(SO 4 ) 2 ㆍ4H2O, Zr(OC 4 H 9 ) 4 Or it could be a combination of these. However, in the case of the raw materials containing the above aluminum, yttrium and zirconium, they may be added together with the lithium raw material in the calcination step described later without being added to the transition metal aqueous solution. At this time, the input amount of each of the above transition metal-containing raw materials can be determined by considering the molar ratio of the transition metal in the cathode material to be ultimately produced. Meanwhile, the ammonium cation complex forming agent is NH 4 OH, (NH 4 ) 2 SO 4 , NH 4 NO 3 , NH 4 Cl, CH 3 COONH 4 and (NH 4 ) 2 CO 3 It may include one or more compounds selected from the group consisting of, and may be introduced into the reactor in the form of a solution in which the compound is dissolved in a solvent. At this time, as the solvent, water or a mixture of water and an organic solvent (specifically, alcohol, etc.) that can be uniformly mixed with water may be used. The above basic compounds are NaOH, KOH and Ca(OH) 2 It may be one or more compounds selected from the group consisting of, and may be introduced into the reactor in the form of a solution in which the compound is dissolved in a solvent. 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. As described above, when a transition metal aqueous solution, an ammonium cation complex forming agent, and a basic compound are placed in a reactor and stirred, the transition metals in the transition metal aqueous solution coprecipitate, generating precursor particles in the form of transition metal hydroxide. At this time, the above transition metal aqueous solution, ammonium cation complex forming agent, and basic compound are added in an amount such that the pH of the reaction solution becomes within the desired range. When the precursor particles are formed in the above manner, the precursor is obtained by separating it from the reaction solution. For example, the precursor can be obtained by filtering the reaction solution to separate the precursor from the reaction solution, and then washing and drying the separated precursor. At this time, processes such as pulverization and / or classification can be performed as needed. Next, the precursor and lithium raw material are mixed and then calcined to produce a lithium nickel-based oxide. At this time, raw materials containing Al and M2 metals may be mixed and calcined together as needed. As the above lithium raw material, lithium-containing sulfate, nitrate, acetate, carbonate, oxalate, citrate, halide, hydroxide or oxyhydroxide can be used, for example, Li 2 CO 3 , LiNO 3 , LiNO 2 , LiOH, LiOHㆍH 2 O, LiH, LiF, LiCl, LiBr, LiI, CH 3 COOLi, Li 2 O, Li 2 SO 4, CH 3 COOLi, Li 3 C 6 H 5 O 7 Or mixtures of these may be used. Meanwhile, the lithium raw material and the precursor may be mixed so that the molar ratio of Li: total metal in the precursor is 1:1 to 1.2:1, preferably 1:1 to 1.1:1. When the mixing ratio of the lithium raw material and the metal in the precursor satisfies the above range, the layered crystal structure of the lithium nickel-based oxide is well developed, so that a cathode material having excellent capacity characteristics and structural stability can be manufactured. Meanwhile, the sintering is performed at a temperature capable of forming single particles or quasi-single particles. In order to form single particles or quasi-single particles, the sintering should be performed at a higher temperature than that in the conventional secondary particle-type lithium nickel-based oxide production, for example, when the precursor composition is the same, the sintering should be performed at a temperature that is about 30°C to 100°C higher than that in the conventional secondary particle-type lithium nickel-based oxide production. The sintering temperature for forming single particles or quasi-single particles may vary depending on the metal composition in the precursor, for example, when forming a High-Ni NCM-based oxide having a Ni content of 80 mol% or more into single particles or quasi-single particles, the sintering temperature may be 800°C to 950°C, preferably 800°C to 900°C. When the sintering temperature satisfies the above range, a cathode material in the form of single particles or quasi-single particles having excellent electrochemical properties can be produced. When the sintering temperature is lower than 800℃, a cathode material in the form of secondary particles is produced, and when it exceeds 950℃, excessive sintering occurs and the layered crystal structure is not properly formed, which may deteriorate the electrochemical characteristics. In addition, the firing can be performed for 5 to 35 hours under an oxygen atmosphere. In the present specification, the oxygen atmosphere means an atmosphere including an air atmosphere and containing oxygen sufficient for firing. In particular, it is preferable to perform the firing in an atmosphere having a higher oxygen partial pressure than an air atmosphere. In addition, when manufacturing the lithium nickel-based oxide of the present invention, it is preferable not to perform the washing process after the calcination. In the past, when manufacturing High-Ni NCM-based oxides, it was common to perform a washing process after the calcination in order to reduce the lithium byproduct content. However, when performing a washing process when manufacturing the single-particle lithium nickel-based oxide of the present invention, it was found that the surface properties of the lithium nickel-based oxide deteriorated during the washing process, thereby increasing the resistance. Therefore, when manufacturing the lithium nickel-based oxide of the present invention, it is preferable not to perform washing, but to consume the residual lithium on the surface of the lithium nickel-based oxide through the coating layer formation process. When manufacturing the lithium nickel-based oxide without washing in this way, the increase in resistance due to surface defects can be suppressed. anode Next, the anode according to the present invention will be described. The positive electrode according to the present invention comprises the positive electrode material described above, and may have a preferred orientation index of 1.2 or more and 1.8 or less, preferably 1.6 or less, and more preferably 1.3 or less according to the above formula 1. As described above, when the preferred orientation index is 1.8 or less, it may contribute to improving the output of the battery. However, considering that the positive electrode material is a single particle type, it is 1.2 or more. Meanwhile, I'(003) / I'(104) of the above formula 1 may be 1.2 to 2.9, preferably 1.2 to 2.6, and more preferably 1.2 to 1.55. I'(003) / I'(104) of the above formula 1 may represent the preferred orientation of the positive electrode. That is, a larger I'(003) / I'(104) value indicates a higher preferred orientation, and a smaller I'(003) / I'(104) value indicates a lower preferred orientation. Considering that a positive electrode including a single-particle type positive electrode material basically has a large preferred orientation as described above, it is preferable that the I'(003) / I'(104) value of the formula 1 is within the above range. Specifically, the positive electrode includes a positive electrode current collector; and a positive electrode composite layer provided on the positive electrode current collector and including the positive electrode material. Since the positive electrode material has been described above, a description of the positive electrode material powder will be omitted, and below, components other than the positive electrode material will be described. In the above positive electrode, the positive electrode 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, sintered carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used. In addition, the positive electrode collector may typically have a thickness of 3 to 500 ㎛, and fine unevenness may be formed on the surface of the positive electrode collector to increase the adhesive strength of the positive electrode material powder. For example, it may 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. Additionally, the above-described positive electrode composite layer may include a conductive material and a binder together with the positive electrode material described above. Meanwhile, the porosity of the above-mentioned anode composite layer may be 10% to 32%, preferably 14% to 28%. When the porosity is low, a conductive path is appropriately formed, which has the advantage of low resistance and high capacity implementation, but low porosity may result in increased preferential orientation, which in turn lowers the output characteristics. Therefore, it is preferable that the porosity of the composite layer is within the above-mentioned range. Here, porosity refers to the value calculated by Equation 3 below. [Formula 3] Porosity of the positive electrode composite layer (%) = ((true density of positive electrode material - electrode density) / true density of positive electrode material) × 100 In the above equation 3, the electrode density is a value calculated by the following equation 4. [Formula 4] Electrode density = (weight of positive electrode - weight of positive electrode current collector) / (a ​​× b × c) In the above equation 4, a, b, and c are the width, length, and height measured after separating the positive electrode current collector from the positive electrode, respectively. Meanwhile, the cathode material may be typically included in an amount of 80 wt% to 99 wt%, preferably 90 wt% to 98 wt%, and more preferably 95 wt% to 97 wt%, based on the total weight of the cathode composite layer. The conductive material is used to provide conductivity to the electrode, and can be used without special restrictions as long as it does not cause a chemical change in the battery to be formed and has electronic conductivity. Specific 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 summer black; carbon-based materials such as carbon fibers and carbon nanotubes; metal powders or metal fibers 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 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 0.5 wt% to 20 wt%, preferably 1 wt% to 10 wt%, and more preferably 1 wt% to 5 wt%, relative to the total weight of the positive electrode mixture layer. The above binder serves to improve the adhesion between the positive electrode particles and the adhesive strength between the positive electrode 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 may be used. The above binder may be included in an amount of 0.5 wt% to 20 wt%, preferably 1 wt% to 10 wt%, and more preferably 1 wt% to 5 wt%, based on the total weight of the positive electrode composite 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 positive electrode material powder, a binder, and / or a conductive material in a solvent to manufacture 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, and may include 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 cathode powder, 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 during subsequent coating for manufacturing the cathode. Alternatively, the positive electrode may be manufactured by casting the positive electrode slurry onto a separate support, peeling the resulting 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 above lithium secondary battery specifically includes a cathode, an anode including an anode active material, and a separator and an electrolyte interposed between the cathode and the anode. Since the cathode is the same as described above, a detailed description is omitted, and only the remaining components are specifically described below. In addition, the lithium secondary battery may optionally further include a battery container that accommodates 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 composite layer provided on the negative electrode current collector. The above negative electrode current collector is not particularly limited as long as it has high conductivity without causing a chemical change 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., an 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, and a non-woven fabric. The above negative electrode composite layer optionally includes a binder and a conductive material together with a negative electrode active material. As the negative electrode active material, a compound capable of reversible intercalation and deintercalation of lithium can 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), SnO 2 , a metal oxide capable of doping and dedoping lithium, such as vanadium oxide, lithium vanadium oxide; or a composite including the above metal compound and a carbonaceous material, such as a Si-C composite or a Sn-C composite, and any one or a mixture of two or more of these may be used. In one embodiment of the present invention, the negative electrode active material may be graphite, the Si-containing material, or a mixture thereof, and specifically, may be graphite, and more specifically, may be a mixture of artificial graphite and natural graphite. In addition, a metallic lithium thin film may be used as the negative electrode active material. The 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 mixture 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 to 10 wt% based on the total weight of the negative electrode composite layer. Examples of such binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, styrene-butadiene rubber, nitrile-butadiene rubber, fluororubber, various copolymers thereof, and the like. The conductive agent is a component for further improving the conductivity of the negative electrode active material, and can be added in an amount of 10 wt% or less, preferably 5 wt% or less, based on the total weight of the negative electrode composite layer. The conductive agent is not particularly limited as long as it has conductivity and does not induce a chemical change in the battery, and for example, graphite such as natural graphite or artificial graphite; carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; conductive fibers such as carbon fiber or metal fiber; fluorinated carbon; metal powder such as aluminum or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; conductive materials such as polyphenylene derivatives, etc. can be used. The above negative electrode composite layer can be manufactured by applying and drying a negative electrode composite 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 negative electrode composite on a separate support and then laminating the resulting film on a negative electrode current collector by peeling it off from the support. 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 that is commonly used as a separator in a lithium secondary battery can be used without special restrictions, and in particular, one that has 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 can be used. In addition, a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc. can also be used. In addition, a coated separator containing a ceramic component or a polymer material to secure heat resistance or mechanical strength can be used, and can optionally be used in a single-layer or multi-layer structure. In addition, the electrolyte used in the present invention may include, but is not limited to, an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel-type polymer electrolyte, a solid inorganic electrolyte, a molten inorganic electrolyte, etc. that can be used in the manufacture of a lithium secondary battery. Specifically, the electrolyte may include an organic solvent and a lithium salt. As the organic solvent, any solvent that can act 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 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; Examples of solvents that can be used include 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 represents 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; and sulfolanes. 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 low-viscosity linear carbonate compound (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 capable of providing lithium ions used in lithium secondary batteries. Specifically, the anion of the above lithium salt is F - , Cl - , Br - , I - , NO 3 - , N(CN) 2 - , BF 4 - , CF 3 CF 2 SO 3 - , (CF 3 SO 2 ) 2 N - , (FSO 2 ) 2 N - , CF 3 CF 2 (CF 3 ) 2 CO - , (CF 3 SO 2 ) 2 CH - , (SF 5 ) 3 C - , (CF 3 SO 2 ) 3 C - , CF 3 (CF 2 ) 7 SO 3 - , CF 3 CO 2 - , CH 3 CO 2 - , SCN - And (CF 3 CF 2 SO 2 ) 2 N - At least one selected from the group consisting of, and the lithium salt is LiPF 6 , LiClO 4, LiAsF 6 , LiBF 4 , LiSbF 6 , LiAlO 2 , LiAlCl 4 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN(C 2 F 5 SO 3 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , LiCl, LiI, or LiB(C 2 O 4 ) 2 The above lithium salt concentration is preferably used within the range of 0.1 to 4.0 M. When the concentration of the lithium salt is within the above range, the electrolyte has appropriate conductivity and viscosity, so that it can exhibit excellent electrolyte performance, and lithium ions can move effectively. In addition to the electrolyte components, the electrolyte may further contain one or more additives, such as, for example, haloalkylene carbonate compounds such as difluoroethylene carbonate, pyridine, triethyl phosphite, triethanolamine, cyclic ethers, ethylene diamine, n-glyme, hexaphosphate triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N,N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxy ethanol, 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. In this case, the additives may be contained in an amount of 0.1 wt% to 5 wt% with respect to the total weight of the electrolyte. There is no particular limitation on the external shape of the lithium secondary battery of the present invention, but it may be in the shape of a cylinder, a square, a pouch, or a coin using a can. As described above, since a lithium secondary battery including a cathode material powder according to the present invention stably exhibits high-temperature performance, it can be used not only in battery cells used as power sources for small devices such as mobile phones, laptop computers, and digital cameras, but can also be suitably used as a unit battery of a battery module for medium- to large-sized devices including a plurality of battery cells. Examples of the above medium and large devices include, but are not limited to, power tools, electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and power storage systems. 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. Hereinafter, embodiments of the present invention will be described in detail so that a person skilled in the art can easily implement the present invention. [Example: Production of cathode material powder] Example 1. D 50 =3.4㎛ and Ni 0.955 Co 0.030 Mn 0.010 Al 0.005 (OH) 2 A precursor having a composition represented by LiOH, Y 2 O 3 and ZrO 2 was added to a Henschel mixer (700 L) and mixed at a central speed of 400 rpm for 20 minutes. At this time, LiOH was added in an amount such that the molar ratio of Li:(Ni+Co+Mn+Al) was 1.05:1, and Y 2 O 3 and ZrO 2Y and Zr were added in amounts such that the weights of Y and Zr were 500 ppm and 2,000 ppm, respectively, relative to the total weight of the lithium nickel oxide finally obtained. The mixed powder was placed in an alumina crucible measuring 330 mm × 330 mm, and oxygen (O 2 ) cathode powder was prepared by calcining at a temperature of 830℃ for 12 hours under an atmosphere. Example 2. Y 2 O 3 and ZrO 2 A cathode material powder was manufactured in the same manner as in Example 1, except that Y and Zr were added in amounts such that the weights of Y and Zr were 400 ppm and 1,500 ppm, respectively, relative to the total weight of the lithium nickel-based oxide finally obtained. Comparative example 1. Y 2 O 3 and ZrO 2 Li[Ni] was prepared in the same manner as in Example 1 except that no 0.955 Co 0.030 Mn 0.010 Al 0.005 ]O 2 A cathode powder having the composition of was manufactured. Comparative example 2. ZrO 2 A cathode powder was prepared in the same manner as in Example 1, except that no addition was made. Comparative example 3. Y 2 O 3 A cathode powder was prepared in the same manner as in Example 1, except that no addition was made. Comparative example 4. Y 2 O 3 and ZrO 2A cathode material powder was manufactured in the same manner as in Example 1, except that the weights of Y and Zr were added in amounts such that they were 1,000 ppm and 3,000 ppm, respectively, relative to the total weight of the lithium nickel-based oxide finally obtained. Comparative Example 5. Y 2 O 3 and ZrO 2 A cathode material powder was manufactured in the same manner as in Example 1, except that the weights of Y and Zr were added in amounts such that they were 1,000 ppm and 4,000 ppm, respectively, relative to the total weight of the lithium nickel-based oxide finally obtained. [Experimental example] Experimental Example 1. Evaluation of the characteristics of the cathode material (1) Check doping content The contents of Y and Zr in each of the cathode material powders manufactured in the above examples and comparative examples were measured using an inductively coupled plasma optical emission spectrometer (ICP-OES; Optima 7300DV, PerkinElmer), and the contents of Y and Zr relative to the total weight and total mole number of the lithium nickel-based oxide were calculated. Using these contents and the doping yield, the composition ratio of each element in the lithium nickel-based oxide was reverse-calculated, and is listed in Table 1 below. (2) D 50 and SEM observation After dispersing 0.1 g of each cathode powder manufactured in the above examples and comparative examples in a dispersion medium, it was introduced into a laser diffraction particle size measuring device (S-3500 from Microtrac) and irradiated with ultrasonic waves of about 28 kHz at an output of 60 W to measure the D of each cathode powder. 50 was measured. The measurement results are shown in Table 1 below. In addition, using a scanning electron microscope, SEM images of each of the cathode material powders manufactured in Examples 1 and 2 and Comparative Examples 1 to 5 were obtained, and these images are attached to FIGS. 1 to 7. (3) Measurement of single particle magnetization Each of the cathode material powders manufactured in the above examples and comparative examples, carbon black, and PVDF binder were mixed in a weight ratio of 95:2:3 in N-methylpyrrolidone to manufacture an electrode slurry. The electrode slurry was applied to one surface of an aluminum current collector, and then dried at 130°C to manufacture an electrode for EBSD analysis. Rolling was not performed. The electrode was cross-sectioned using an ion milling device (HITACHI IM-5000, acceleration voltage 6 kV), and EBSD analysis was performed on the electrode cross-section using FE-SEM (JEOL JSM7900F) equipped with a backscatter electron diffraction pattern analyzer (EBSD). The EBSD analysis was performed under the conditions of an acceleration voltage of 15 kV, a WD of 15 mm, and a scale where the total number of grains was approximately 400+ / -10. The diameter of each grain observed in each electrode cross-section was measured through EBSD analysis, and the half of the maximum diameter of the measured grain was calculated as the grain radius, and the arithmetic mean of the diameters of the measured grains was calculated as the average grain diameter. In addition, the diameter of the grain and the D measured in (1) above were calculated. 50 The single particle magnetization degree was calculated by substituting it into the above equation [Equation 2]. The measurement results are shown in Table 1 below. Additionally, FIGS. 8 to 14 show EBSD maps of cross-sections of electrodes manufactured using the cathode material powders of Examples 1 and 2 and Comparative Examples 1 to 5, respectively. Doping element content (ppm)Doping element content (mol%)NCMA composition ratio (mol%)Cathode powder D 50[㎛]Average grain diameter[㎛]Single particle magnetization degree of formula 2YZrYZrNiCoMnAlExample 15002,0000.05000.210095.25172.99220.99740.49873.841.623.4Example 24001,5000.04000.160095.30902.99400.99800.49903.721.593.34Comparative Example 1----95.53.01.00.53.551.101.6Comparative Example 2500-0.0500-95.452252.998500.999500.499753.681.221.8Comparative Example 3-2,000-0.210095.299452.993700.997900.498954.021.543.2Comparative Example 41,0003,0000.10000.320095.09892.98740.99580.49794.081.743.63Comparative Example 51,0004,0000.10000.430094.993852.98410.99470.497354.141.823.9 Experimental Example 2. Measurement of the Preferred Orientation Index of the Anode (1) X-ray diffraction analysis of cathode powder Each of the cathode material powders manufactured in the above examples and comparative examples was placed in a holder inside an XRD measuring device (Bruker D8 Endeavor), and the surface was leveled using a slide glass so that the sample height was the same as the edge of the holder, and X-ray diffraction analysis was performed under the conditions described above. However, since pressure is applied to the powder during the process of leveling the surface, which may cause a preferred orientation, a back loading holder was used to analyze the sample on the opposite side to which pressure was applied to prevent this. The measured peak intensities of the (104) plane and (003) plane are shown in Table 2 below. (2) X-ray diffraction analysis of the anode Each of the cathode material powders manufactured in the above examples and comparative examples, carbon black, and PVDF binder were mixed in a weight ratio of 95:2:3 in N-methylpyrrolidone to manufacture a cathode slurry. The cathode slurry was applied to one surface of a 15 ㎛ thick aluminum current collector to form a cathode mixture layer, and then dried at 130°C and rolled under the condition that the porosity of the cathode mixture layer became 24% to manufacture a cathode. The manufactured anode was cut to the size of the sample holder to make a specimen, which was then firmly attached to a glass plate using double-sided tape so that it would not float, and then fixed to a PMMA holder in an XRD measuring device (Bruker D8 Endeavor) using rubber clay, and X-ray diffraction analysis was performed under the conditions described above. The measured peak intensities of the (104) plane and (003) plane and the preferred orientation index according to [Equation 1] reflecting the peak intensities were calculated and shown in Table 2 below. I(003) / I(104)I'(003) / I'(104)Preferred orientation index of equation 1Example 11.201.51.25Example 21.191.441.21Comparative example 11.211.5971.32Comparative example 21.221.6471.35Comparative example 31.212.6742.21Comparative example 41.291.411.09Comparative example 51.432.831.98 Experimental Example 3. Monocell Performance Evaluation (1) Manufacturing of monocell A cathode to which the cathode material powder of the above examples and comparative examples was applied was manufactured using the same method as (2) of the above experimental example 2. Meanwhile, a mixture of natural graphite and artificial graphite as negative active materials in a weight ratio of 50:50, SBR and CMC as binders, and Super C as a conductive agent were mixed in a weight ratio of 95.6:1.1:2.3:1.0 in water as a solvent to prepare a negative electrode slurry having a solid content of 60 wt%. The negative electrode slurry was applied to both sides of a 10 ㎛ thick copper current collector, dried at 130°C, and then rolled between two rolling rolls to prepare a negative electrode. An electrode assembly was manufactured by interposing a 15 μm thick porous polyethylene separator between the manufactured positive and negative electrodes, and then inserted into a pouch-type battery case and an electrolyte was injected to manufacture a monocell. At this time, 1 M LiPF was added to an organic solvent mixed with ethylene carbonate (EC): ethyl methyl carbonate (EMC) in a volume ratio of 1:2 as the electrolyte. 6 A solution containing dissolved was used. (2) High temperature life evaluation For each monocell manufactured in (1) above, an activation (formation) process was performed, and then the cell was charged under constant current-constant voltage conditions at 0.5 C (reference capacity 1.0 C = 200 mAh / g) at 45°C using a PNE-0506 charger / discharger (manufacturer: PNE Solution Co., Ltd.), and discharged at a constant current of 1.0 C to 2.5 V. This charge / discharge process was considered as one cycle, and the initial discharge capacity was measured after one cycle, and then the discharge capacity was measured while repeating the same charge / discharge process for 300 cycles. Based on this, the capacity retention rate compared to the initial discharge capacity was calculated, and is shown in Table 3. (3) Rate capability evaluation For each monocell manufactured in (1) above, an activation (formation) process was performed, and then the cell was charged under constant current-constant voltage conditions at 45°C at 0.5C (reference capacity 1.0C = 200mAh / g) to 4.25 V using a PNE-0506 charger / discharger (manufacturer: PNE Solution Co., Ltd.), and discharged at a constant current of 0.1C to 2.5 V. After that, the cell was charged under the same conditions, the discharge rate was changed to 2.0C, and the discharge capacity was measured. The rate characteristics obtained by measuring the discharge capacity at 2.0C compared to 0.1C are shown in Table 3 below. Rate characteristics [%] Capacity retention [%] Example 191.892.5 Example 292.292.3 Comparative example 192.181.5 Comparative example 291.982.6 Comparative example 385.891.4 Comparative example 488.390.2 Comparative example 587.593.1 Through Table 3, it can be confirmed that the cells including the positive electrodes of Examples 1 and 2, which include positive electrode materials doped with Y and Zr and have a preferred orientation index of 1.2 to 1.8, have excellent rate characteristics and capacity retention ratio. On the other hand, in the case of the positive electrodes including the positive electrode materials of Comparative Example 1, which do not include both Y and Zr, and Comparative Example 2, which dope only with Y, the effect of improving the capacity retention ratio of the cell is significantly reduced compared to Examples 1 and 2, even when the preferred orientation index is in the range of 1.2 to 1.8. In addition, it can be confirmed that the cell including the positive electrode of Comparative Example 3 having a priority orientation index exceeding 1.8 has significantly lower rate characteristics compared to Examples 1 and 2. In addition, even if the cathode material doped with Y and Zr is included, in the case of a cathode having a preferred orientation index of less than 1.2, such as in Comparative Example 4, the effect of improving the rate characteristics and capacity retention of the cell is greatly reduced compared to Examples 1 and 2, and in the case of a cathode having a preferred orientation index of more than 1.8, such as in Comparative Example 5, the effect of improving the rate characteristics of the cell is greatly reduced compared to Examples 1 and 2.

Claims

1. A cathode material comprising a single particle lithium nickel oxide containing Y and Zr, An anode having a preferred orientation index of 1.2 or more and 1.8 or less according to the following equation: [Formula 1] In the above equation 1, I(003) / I(104) is the ratio of the peak intensity I(003) of the (003) plane to the peak intensity I(104) of the (104) plane obtained by XRD analysis of the above cathode material. I'(003) / I'(104) is the ratio of the peak intensity I'(003) of the (003) plane to the peak intensity I'(104) of the (104) plane obtained by XRD analysis of the above anode.

2. In claim 1, A cathode having a single particle magnetization degree of 2.0 or more and 4.5 or less according to the following formula 2 of the cathode material: [Formula 2] In the above equation 2, R i is the radius of the i-th grain measured when the electrode manufactured by applying the above cathode material is subjected to ion milling treatment and then analyzed by backscatter electron diffraction (EBSD). Although it is a value measured in μm, the value substituted into Equation 2 is a unitless number that does not include a unit. n is the total number of grains measured through the above EBSD analysis, which is 350 to 450.

3. In claim 1, D of the above cathode material 50 This positive electrode is 1.0㎛ to 6.0㎛.

4. In claim 1, A cathode, wherein the above Y is contained in an amount of 200 ppm to 800 ppm based on the total weight of the lithium nickel-based oxide.

5. In claim 1, A cathode, wherein the Zr is contained in an amount of 1,000 ppm to 3,000 ppm based on the total weight of the lithium nickel-based oxide.

6. In claim 1, The above lithium nickel-based oxide has a composition of the following chemical formula 1, the positive electrode: [Chemical Formula 1] Li a Ni 1-x-y Co x M1 y M2 w O 2 In the above chemical formula 1, 1.0≤a≤1.5, 0≤x≤0.2, 0≤y≤0.2, 0 <w≤0.1, 0<x+y≤0.2이고, M1 is at least one selected from the group consisting of Mn and Al, M2 is two or more elements selected from the group consisting of Y, Zr, Ba, Ca, Ti, Mg, Ta, Nb, and Mo, but Y and Zr are necessarily included.

7. In claim 1, An anode having I(003) / I(104) of the above formula 1 of 1.0 to 1.

6.

8. In claim 1, An anode having I'(003) / I'(104) of the above formula 1 of 1.2 to 2.

9.

9. In claim 1, The above positive electrode comprises a positive electrode current collector; and a positive electrode composite layer provided on the positive electrode current collector and including the positive electrode material, An anode having a porosity of the above-mentioned anode composite layer of 10% to 32%.

10. A lithium secondary battery comprising a positive electrode according to claim 1; a negative electrode including a negative electrode active material; a separator interposed between the positive electrode and the negative electrode; and an electrolyte.

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