Precursor for cathode active material, cathode active material, method for manufacturing precursor for cathode active material, cathode, and lithium secondary battery

Abstract

The present invention relates to a precursor for a cathode active material, the precursor comprising a nickel-based hydroxide containing 60 mol% or more of nickel relative to the total metal, wherein the ratio of the grain size of the (101) plane (unit: nm) to the amount (unit: mol%) of Ni relative to the total metal is 1.5-2.0 nm / mol%.

Description

Precursor for positive electrode active material, positive electrode active material, method for manufacturing a precursor for a positive electrode active material, positive electrode and lithium secondary battery

[0001] Cross-citation with related applications

[0002] The present application claims the benefit of priority based on Korean Patent Application No. 10-2025-0027118 filed on February 28, 2025 and Korean Patent Application No. 10-2026-0037046 filed on February 27, 2026, and all contents disclosed in said Korean patent application documents are incorporated into this specification.

[0003] Technology field

[0004] The present invention relates to a precursor for a positive electrode active material, a positive electrode active material, a method for manufacturing a precursor for a positive electrode active material, a positive electrode, and a lithium secondary battery.

[0005]

[0006] Lithium-ion secondary batteries are widely used in various fields, such as portable electronic devices, electric vehicles, and energy storage systems (ESS), due to their high energy density and excellent cycle characteristics. To improve the performance of these lithium-ion secondary batteries, various compositions have been studied as cathode active materials. For example, high-nickel cathode active materials with a high nickel (Ni) content are attracting attention as cathode materials for next-generation batteries because they enable the realization of high capacity and high energy density.

[0007] However, high-nickel cathode active materials still require improvement in terms of structural and chemical stability.

[0008]

[0009] The present invention provides a precursor for a positive electrode active material, a positive electrode active material, a method for manufacturing a precursor for a positive electrode active material, a positive electrode, and a lithium secondary battery, wherein the resistance and lifespan characteristics are improved by reducing electrolyte side reactions while having excellent capacity characteristics.

[0010]

[0011] [1] The present invention provides a precursor for an anode active material comprising a nickel-based hydroxide containing 60 mol% or more of nickel in the total metal, and having a ratio of (101) plane direction grain size (unit: nm) to the content of Ni in the total metal (unit: mol%) of 1.5 nm / mol% to 2.0 nm / mol%.

[0012] [2] The present invention is a precursor for an anode active material, wherein, in [1] above, the nickel-based hydroxide is represented by the following chemical formula 1.

[0013] [Chemical Formula 1]

[0014] Ni x0 Co y0 M 1 z0 M 2 w0 (OH)2

[0015] In the above chemical formula 1,

[0016] 0.60≤x0<1.0, 0 <y0≤0.3, 0<z0≤0.3, 0≤w0≤0.1이고, M 1 is Mn, Al, or a combination thereof, and M 2 It is one or more doping elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo.

[0017] [3] The present invention, in [1] or [2] above, has an average particle size D 50 This provides a precursor for a positive electrode active material having a thickness of 10.0㎛ to 15.0㎛.

[0018] [4] The present invention provides a precursor for an anode active material, wherein, in at least one of [1] to [3], the nickel content of the total metal is 70 mol% to 80 mol%.

[0019] [5] The present invention provides a precursor for an anode active material, wherein, in at least one of [1] to [4], the (101) plane direction grain size is 100 nm to 200 nm.

[0020] [6] The present invention provides a precursor for a positive electrode active material, wherein the I(001) / I(100) value measured by XRD is 3.0 to 4.0 in at least one of [1] to [5].

[0021] [7] The present invention provides a positive electrode active material comprising a lithium nickel-based oxide containing 60 mol% or more of nickel among all metals excluding lithium, and having a ratio of average grain size (unit: nm) to the content of Ni (unit: mol%) among all metals excluding lithium to 1.9 nm / mol% to 3.0 nm / mol%.

[0022] [8] The present invention provides a positive active material, wherein the positive active material of [7] comprises secondary particles.

[0023] [9] The present invention, in [7] or [8] above, has an average particle size D 50 This provides a positive electrode active material having a thickness of 10.0㎛ or more and 15.0㎛ or less.

[0024]

[0010] The present invention provides a positive electrode active material, wherein, in at least one of [7] to [9], the average grain size is 500 nm to 800 nm.

[0025]

[0011] The present invention provides a positive electrode active material in which, in at least one of [7] to

[0010] , the I(003) / I(104) value measured by XRD is 1.0 to 2.0.

[0026]

[0012] The present invention provides a positive electrode comprising a positive electrode active material according to any one of [7] to

[0011] .

[0027]

[0013] The present invention provides a lithium secondary battery comprising: a positive electrode according to

[0012] ; a negative electrode disposed opposite to the positive electrode; and an electrolyte.

[0028]

[0014] The present invention provides a method for manufacturing a positive electrode active material comprising the step of mixing and calcining a lithium raw material with a precursor for a positive electrode active material containing 60 mol% or more of nickel in the total metal, wherein the ratio of (101) plane grain size (unit: nm) to the content of Ni in the total metal (unit: mol%) is 1.5 nm / mol% to 2.0 nm / mol%.

[0029]

[0015] The present invention provides a method for manufacturing an anode active material, wherein, in

[0014] the calcination is performed at a temperature of 600°C to 900°C.

[0030]

[0016] The present invention provides a method for manufacturing a positive electrode active material, wherein the precursor for the positive electrode active material according to

[0014] is manufactured through: (1) a nucleation step of forming a nucleus for the positive electrode active material by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound to obtain a reaction solution; and (2) a particle growth step of growing a precursor particle for the positive electrode active material by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound while supplying them to the reaction solution in which the nucleus for the positive electrode active material is formed.

[0031]

[0017] The present invention provides a method for manufacturing an anode active material, wherein, in

[0016] , step (1) is performed in a first reactor, and step (2) is performed after moving the reaction solution in which the precursor nucleus for the anode active material is formed from the first reactor to a second reactor.

[0032]

[0033] The precursor for a positive electrode active material according to the present invention comprises a nickel-based hydroxide containing 60 mol% or more of nickel among the total metals, and the ratio of the (101) plane crystal size (unit: nm) to the content of Ni among the total metals (unit: mol%) satisfies a specific range. The present invention enables the realization of high capacity by ensuring that the nickel-based hydroxide contains 60 mol% or more of nickel among the total metals. Furthermore, the present invention designs the (101) plane crystal size to an optimal range according to the nickel content in the precursor for a positive electrode active material before calcination, so that even without increasing the calcination temperature, the average crystal size relative to the nickel content of the positive electrode active material can be controlled to a range that ensures structural stability and lithium ion diffusion, thereby suppressing the formation of surface rock salt phases and improving the structural stability of the positive electrode active material.

[0034] In addition, the positive electrode active material according to the present invention contains 60 mol% or more of nickel among the total metals excluding lithium, and the average grain size relative to the nickel content among the total metals excluding lithium satisfies a specific range. Accordingly, the formation of surface rock salt phases is suppressed and crystallinity can be excellent, so the structural stability of the positive electrode active material and the diffusivity of lithium ions can be excellent.

[0035] The positive electrode and lithium secondary battery according to the present invention, by including the positive electrode active material according to the present invention, can have excellent capacity characteristics and excellent high-temperature life characteristics, and can also improve the problem of increased battery resistance.

[0036]

[0037] The following drawings attached to this specification illustrate embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0038] FIG. 1 is a flowchart illustrating a method for manufacturing a positive electrode active material according to one embodiment of the present invention.

[0039] FIG. 2 is a flowchart illustrating a method for manufacturing a precursor for a positive electrode active material according to one embodiment of the present invention.

[0040] In the attached drawings, elements of known technology that are useful or essential in commercially viable embodiments may often not be depicted so as not to interfere with the spirit of the various embodiments of the present invention.

[0041]

[0042] Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0043] The terms used in this specification are used merely to describe exemplary embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0044] In this specification, terms such as “comprising,” “having,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0045] In the present invention, "single-particle type particle" refers to a particle composed of 30 or fewer sub-particles. The sub-particle unit constituting the single-particle type particle shall be referred to as a "nodule." The single-particle type particle includes a single particle composed of one nodule and a pseudo-single particle which is a complex of 30 or fewer nodules.

[0046] The above “nodule” refers to a sub-particle unit body constituting a single particle and a pseudo-single particle, and the nodule may be a single crystal lacking crystalline grain boundaries, or a polycrystalline material in which grain boundaries are not apparent when observed at a field of view of 5,000 to 20,000 times using a scanning electron microscope (SEM).

[0047] In the present invention, "secondary particle" refers to a particle formed by the aggregation of more than 30 sub-particles. In order to distinguish it from the sub-particles constituting the single-particle type particle, each lower particle unit constituting the secondary particle is called a "primary particle."

[0048] The expression “particle” used in the present invention may include any one or all of a single particle, a pseudo-single particle, a primary particle, a nodule, and a secondary particle.

[0049] In the present invention, "average particle size D 50"This refers to the particle size corresponding to 50% of the volume-based particle size distribution of the powder to be measured, and can be measured using the laser diffraction method. For example, the powder to be measured can be measured by dispersing it in a dispersion medium, introducing it into a commercially available laser diffraction particle size measuring device (e.g., Microtrac MT 3000), irradiating it with ultrasound of about 28 kHz at an output of 60 W, obtaining a volume-based particle size distribution graph, and then determining the particle size corresponding to 50% of the volume-based particle size.

[0050] In the present invention, “crystallite” refers to a distinct region in which atoms form a lattice structure of a certain orientation, and means a particle unit having substantially the same crystal orientation.

[0051] In the present invention, “average grain size” refers to the overall average value of all grain sizes measured by X-ray diffraction analysis (XRD), and can be obtained through the Rietveld method using XRD data. For example, the “average grain size” can be obtained by placing a sample in the recessed groove in the center of a general powder holder, smoothing the surface of the sample using a slide glass while simultaneously making the height equal to the edge of the holder, and then measuring the XRD data using an X-ray diffraction analyzer (Bruker, D8 Endeavor) (light source: Cu Kα, λ=1.54Å, 2θ=10°~80°, Step size=0.02°, total scan time: 120min) and analyzing the XRD data through the Fundamental Parameter Approach embedded in Bruker’s TOPAS program based on the Rietveld method.

[0052] In the present invention, “(101) plane direction grain size” refers to the average value of the (101) plane direction grain size measured by X-ray diffraction analysis (XRD), and can be obtained through the Rietveld method using XRD data. For example, the “(101) plane direction grain size” can be obtained by placing a sample in the recessed groove in the center of a general powder holder, smoothing the surface of the sample using a slide glass while simultaneously making the height equal to the edge of the holder, and then measuring the XRD data using an X-ray diffraction analyzer (Bruker, D8 Endeavor) (light source: Cu Kα, λ=1.54Å, 2θ=10°~80°, Step size=0.02°, total scan time: 120 min) and analyzing the XRD data through the Fundamental Parameter Approach embedded in Bruker’s TOPAS program based on the Rietveld method.

[0053] In the present invention, the “I(001) / I(100) value” refers to the ratio of the peak intensity I(001) of the (001) plane to the peak intensity I(100) of the (100) plane obtained by X-ray diffraction analysis (XRD) of the target material. For example, the “I(001) / I(100) value” can be measured by fixing the target sample to a holder, obtaining XRD data measured using an X-ray diffraction analyzer (Bruker, D8 Endeavor) (light source: Cu Kα, λ=1.54Å, 2θ=10°~80°, Step size=0.02°, total scan time: 120min), and fitting using only the Lorenzian contribution as the FP (First Principle) among the peak types available in TOPAS using all peaks of the measurement range. At this time, strain is not considered.

[0054] In the present invention, the “I(003) / I(104) value” refers to the ratio of the peak intensity I(003) of the (003) plane to the peak intensity I(104) of the (104) plane obtained by X-ray diffraction analysis (XRD) of the target material. For example, the “I(003) / I(104) value” can be measured by fixing the target sample to a holder, obtaining XRD data measured using an X-ray diffraction analyzer (Bruker, D8 Endeavor) (light source: Cu Kα, λ=1.54Å, 2θ=10°~80°, Step size=0.02°, total scan time: 120min), and fitting using only the Lorenzian contribution as the FP (First Principle) among the peak types available in TOPAS using all peaks of the measurement range. At this time, strain is not considered.

[0055]

[0056] Recently, as the demand for improved capacity characteristics of secondary batteries has increased, attempts are being made to increase the nickel content in cathode active materials. However, while capacity increases as the nickel content in the cathode active material rises, there is a problem of structural instability due to factors such as the incorporation of nickel and lithium ions or structural transitions at high voltages.

[0057] Furthermore, side reactions with the electrolyte are accelerated, and by-products generated at the interface between the electrode and the electrolyte cause an increase in interfacial resistance. This leads to a deterioration in the battery's resistance characteristics and a degradation in lifespan characteristics during long-term charge-discharge cycles. Therefore, there is a need to develop cathode active materials that possess excellent capacity characteristics, improved structural stability, and the ability to reduce electrolyte side reactions.

[0058]

[0059] The present invention, taking this into consideration, provides a configuration that secures the stability of the internal structure of the positive electrode active material itself. For example, since the degree of structural instability varies depending on the nickel content, the present invention provides a configuration that optimizes the internal structure of the positive electrode active material according to the nickel content. In addition, the grain size of the positive electrode active material is closely related to the degree of formation of grain boundaries where structural defects are likely to occur, and this can affect the degree of internal cracking within the crystal, thereby acting as a factor that determines the structural stability of the positive electrode active material.

[0060] Accordingly, the present invention can provide the effect of improving high-temperature life characteristics and resistance characteristics by optimizing the grain size according to the nickel content in the positive electrode active material, thereby ensuring the structural stability of the positive electrode active material even when the nickel content increases.

[0061] In addition, the present invention can manufacture a positive electrode active material by controlling the physical properties of the precursor itself for the positive electrode active material.

[0062]

[0063] A precursor for a positive electrode active material, a positive electrode, a lithium secondary battery, and / or a method for manufacturing a precursor for a positive electrode active material according to the present invention comprises at least one of the configurations disclosed below, and may comprise any combination of technically feasible configurations among the configurations below.

[0064]

[0065] Precursor for positive electrode active material

[0066] The precursor for a positive electrode active material according to the present invention comprises a nickel-based hydroxide containing about 60 mol% or more of nickel among the total metals. For example, the precursor for a positive electrode active material may comprise a nickel-based hydroxide containing 60 mol% or more, 65 mol% or more, 70 mol% or more, less than 100 mol%, 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, 75 mol% or less, 72 mol% or less, or 70 mol% or less of nickel among the total metals. Alternatively, the precursor for a positive electrode active material may comprise a nickel-based hydroxide containing 60 mol% or more, 65 mol% or more, 70 mol% or more, 70 mol% to 90 mol%, 70 mol% to 80 mol%, or 70 mol% to 75 mol% of nickel among the total metals. When the above ranges are satisfied, a positive electrode active material with high energy density can be manufactured, and the capacity characteristics of the battery can be excellent.

[0067]

[0068] The above nickel-based hydroxide can be represented by the following chemical formula 1.

[0069] [Chemical Formula 1]

[0070] Ni x0 Co y0 M 1 z0 M 2 w0 (OH)2

[0071] In the above chemical formula 1, M 1 can be Mn, Al, or a combination thereof. The above M 1 If included, the structural stability of nickel-based hydroxides can be improved.

[0072] In the above chemical formula 1, M 2... may be one or more doping elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo, or may be one or more doping elements selected from the group consisting of W, Y, Ba, Ca, Ti, Mg, Ta, and Nb. 2 It may be optionally included in or not included in the nickel-based hydroxide represented by the above chemical formula 1, and if included, it may play a role in facilitating calcination or improving structural stability.

[0073] In the above chemical formula 1, x0 represents the molar ratio of nickel among the total metals in the nickel-based hydroxide particles, and may be 0.60≤x0<1.0, 0.65≤x0<1.0, 0.70≤x0<1.0, 0.70≤x0≤0.90, 0.70≤x0≤0.80, or 0.70≤x0≤0.75. When the above range is satisfied, the capacity characteristics of the manufactured cathode active material are excellent, and structural stability can be secured.

[0074] In the above Chemical Formula 1, y0 represents the molar ratio of cobalt among the total metals in the nickel-based hydroxide particles, where 0 <y0≤0.3, 0<y0≤0.2, 0<y0≤0.15, 또는 0<y0≤0.1일 수 있다. 상기 범위를 만족하는 경우, 비용적인 이점을 가지면서, 출력 특성이 개선될 수 있다.

[0075] In the above Chemical Formula 1, z0 is M of the total metal in the nickel-based hydroxide particles. 1 It refers to the molar ratio of, 0 <z0≤0.3, 0<z0≤0.25, 또는 0<z0≤0.2일 수 있다. 상기 범위를 만족하는 경우, 상기 화학식 1로 표시되는 양극 활물질용 전구체를 이용하여 제조된 양극 활물질의 구조적 안정성이 개선될 수 있다.

[0076] In the above Chemical Formula 1, w0 is M of the total metal in the nickel-based hydroxide particles 2 It refers to the molar ratio, which may be 0≤w0≤0.1, 0≤w0≤0.08, 0≤w0≤0.05, or 0≤w0≤0.01. When the above range is satisfied, it can play a role in promoting particle growth during calcination of the positive active material prepared using the precursor for the positive active material represented by Chemical Formula 1, or improving crystal structure stability.

[0077]

[0078] The above precursor for the positive electrode active material may include a nickel-based hydroxide comprising nickel, cobalt, and manganese. For example, the above precursor for the positive electrode active material may include a nickel-based hydroxide represented by the following chemical formula 1-1. When the nickel-based hydroxide includes manganese, structural stability may be improved as the manganese contributes to maintaining the layered structure of the nickel-based hydroxide.

[0079] [Chemical Formula 1-1]

[0080] Ni x1 Co y1 Mn z1 M 2 w1 (OH)2

[0081] In the above chemical formula 1-1, M 2 ... may be one or more doping elements selected from the group consisting of Al, W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo, or may be one or more doping elements selected from the group consisting of Al, W, Y, Ba, Ca, Ti, Mg, Ta, and Nb. 2 It may be optionally included in or not included in the nickel-based hydroxide represented by the above chemical formula 1-1, and if included, it may play a role in facilitating calcination or improving structural stability.

[0082] In the above chemical formula 1-1, x1 represents the molar ratio of nickel among the total metals in the nickel-based hydroxide particles, and may be 0.60≤x1<1.0, 0.65≤x1<1.0, 0.70≤x1<1.0, 0.70≤x1≤0.90, 0.70≤x1≤0.80, or 0.70≤x1≤0.75. When the above range is satisfied, the capacity characteristics of the cathode active material prepared using the nickel-based hydroxide represented by the above chemical formula 1-1 may be excellent.

[0083] In the above chemical formula 1-1, y1 represents the molar ratio of cobalt among the total metals in the nickel-based hydroxide particles, where 0 <y1≤0.3, 0<y1≤0.2, 0<y1≤0.15, 또는 0<y1≤0.1일 수 있다. 상기 범위를 만족하는 경우, 비용적인 이점을 가지면서, 출력 특성이 개선될 수 있다.

[0084] In the above Chemical Formula 1-1, z1 represents the molar ratio of manganese among the total metals in the nickel-based hydroxide particles, where 0 <z1≤0.3, 0<z1≤0.25, 또는 0<z1≤0.2일 수 있다. 상기 범위를 만족하는 경우, 상기 화학식 1-1으로 표시되는 니켈계 수산화물을 이용하여 제조된 양극 활물질의 구조적 안정성이 개선될 수 있다.

[0085] In the above chemical formula 1-1, w1 is M of the total metal in the nickel-based hydroxide particle. 2 It refers to the molar ratio of 0≤w1≤0.1, 0≤w1≤0.08, 0≤w1≤0.05, or 0≤w1≤0.01. When the above range is satisfied, the structural stability of the cathode active material prepared using the nickel-based hydroxide represented by Chemical Formula 1-1 can be improved.

[0086]

[0087] The above precursor for the positive electrode active material has a ratio of (101) plane direction grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal to 1.5 nm / mol% to 2.0 nm / mol%.

[0088] The present invention aims to achieve excellent structural stability and improve high-temperature lifespan and resistance characteristics by providing an anode active material with an optimized average grain size according to nickel content. The present invention relates to the oxygen release and Ni during the manufacture of a high-concentration nickel anode active material. 2+ The calcination temperature can be precisely controlled to suppress the formation of surface rock salt phases due to increased ions. For example, by maintaining relatively low calcination temperature conditions, chemical degradation can be suppressed, while simultaneously optimizing the physical properties of the precursor itself for the cathode active material to induce smooth grain growth.

[0089] The present invention enables the production of an anode active material having an optimal average grain size according to nickel content even at a relatively low calcination temperature by controlling the characteristics of the precursor itself rather than the calcination temperature.

[0090] For example, according to one embodiment of the present invention, the (101) plane direction grain size of the precursor for the positive active material satisfies a specific range depending on the nickel content. The (101) plane in the precursor for the positive active material corresponds to the (104) plane in the positive active material, where the (104) plane corresponds to a plane in which the lithium layer and the metal layer are projected in a mixture, representing the arrangement state of the transition metal sublattice structure and reflecting the crystallinity of the positive active material. Furthermore, among the major crystal planes of the positive active material, the (104) plane is associated with the formation of long-range order of the transition metal sublattice and grows diffusion-dominantly, so its growth may be relatively more restricted at a relatively low calcination temperature. Accordingly, when calcined at a relatively low temperature, the (101) plane direction grain size of the precursor for the positive active material may have a greater influence on controlling the average grain size according to the nickel content of the positive active material.

[0091] Accordingly, by designing a precursor for a positive electrode active material such that the ratio of the (101) plane direction grain size according to the nickel content satisfies the above range, the present invention enables the production of a positive electrode active material in which the average grain size according to the nickel content satisfies a specific range without increasing the calcination temperature, and further enables the production of a positive electrode active material with excellent structural stability due to excellent crystallinity. As a result, the resistance characteristics and high-temperature life characteristics of the battery can be excellent.

[0092] For example, the ratio of the (101) plane direction grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal may be 1.5 nm / mol% or more, 1.55 nm / mol% or more, 1.6 nm / mol% or more, 1.65 nm / mol% or more, 1.7 nm / mol% or more, 1.75 nm / mol% or more, 1.8 nm / mol% or more, 2.0 nm / mol% or less, 1.97 nm / mol% or less, 1.95 nm / mol% or less, 1.91 nm / mol% or less, 1.9 nm / mol% or less, 1.85 nm / mol% or less, or 1.8 nm / mol% or less. Alternatively, the ratio of the (101) plane direction grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal may be about 1.5 nm / mol% to 2.0 nm / mol%, 1.6 nm / mol% to 1.97 nm / mol%, 1.7 nm / mol% to 1.95 nm / mol%, or 1.8 nm / mol% to 1.91 nm / mol% in the precursor for the positive electrode active material.

[0093] If the crystal grain size in the (101) plane direction relative to the nickel content in the precursor for the positive active material is excessively large, the crystal structure may collapse and a rock-salt phase may be formed. Alternatively, if the crystal grain size in the (101) plane direction relative to the nickel content in the precursor for the positive active material is excessively small, sufficient crystallinity cannot be secured in the positive active material being manufactured, which may result in problems such as reduced capacity development, reduced structural stability, and reduced resistance characteristics. Therefore, if the crystal grain size in the (101) plane direction relative to the nickel content in the precursor for the positive active material satisfies the above range, the formation of a surface rock-salt phase is suppressed and excellent crystallinity may be achieved. In addition, when manufacturing a positive active material containing a high amount of nickel (e.g., 60 mol% or more, or 65 mol% or more, or 70 mol% to 80 mol%), it may be easy to manufacture a positive active material having an optimal average crystal grain size according to the nickel content without raising the calcination temperature due to rock-salt phase formation, oxygen desorption, etc. Accordingly, the structural and electrochemical stability of the positive electrode active material can be excellent, and the resistance characteristics can be excellent, and the capacity characteristics, high-temperature life characteristics, and output characteristics of the battery can be excellent.

[0094]

[0095] The content of Ni among the total metals above may be 60 mol% or more, 65 mol% or more, 70 mol% or more, 70 mol% to 90 mol%, 70 mol% to 80 mol%, or 70 mol% to 75 mol%. When the above range is satisfied, the manufactured cathode active material can have excellent energy density and structural stability can be ensured.

[0096] The above (101) plane direction crystal grain size may be 100 nm to 200 nm, 110 nm to 140 nm, or 120 nm to 130 nm. When the above range is satisfied, the crystal structure of the manufactured cathode active material becomes more stable, and high capacity characteristics can be achieved.

[0097]

[0098] The above precursor for the positive electrode active material may have an I(001) / I(100) value measured by XRD of 3.0 to 4.0, 3.2 to 3.90, 3.35 to 3.80, 3.36 to 3.70, 3.37 to 3.60, 3.38 to 3.50, or 3.39 to 3.45. When the above range is satisfied, the crystal orientation of the precursor for the positive electrode active material is secured at a certain level or higher, so that the structural stability may be excellent. Accordingly, the crystallinity of the manufactured positive electrode active material is controlled, so that a layered structure is well formed and the mixing of cations between lithium ions and nickel ions is low, thereby improving the structural stability of the positive electrode active material, and the resistance may be reduced and the lifespan characteristics may be excellent.

[0099]

[0100] The above precursor for the positive electrode active material has an average particle size D 50 This may be 10.0㎛ to 15.0㎛, 11.0㎛ to 14.0㎛, 11.5㎛ to 13.5㎛, or 12.0㎛ to 13.0㎛. When the above range is satisfied, the size of the manufactured positive electrode active material is appropriate, so particle breakage during electrode rolling can be reduced. Accordingly, cracks in the electrode can be prevented, thereby suppressing an increase in resistance or a decrease in lifespan.

[0101]

[0102] positive active material

[0103] The positive electrode active material according to the present invention comprises a lithium nickel-based oxide containing 60 mol% or more of nickel among the total metals excluding lithium. For example, the positive electrode active material according to the present invention may comprise a lithium nickel-based oxide containing 60 mol% or more, 65 mol% or more, 70 mol% or more, 70 mol% to 90 mol%, 70 mol% to 80 mol%, or 70 mol% to 75 mol% of nickel among the total metals excluding lithium. In this case, the energy density of the positive electrode active material may be excellent, and the capacity characteristics may be excellent.

[0104]

[0105] The above lithium nickel-based oxide can be represented by the following chemical formula 2.

[0106] [Chemical Formula 2]

[0107] Li 1+a1 [Ni x2 Co y2 M 3 z2 M 4 w2 ]O2

[0108] In the above chemical formula 2, M 3 can be Mn, Al, or a combination thereof. The above M 3 If included, the structural stability of the lithium nickel-based oxide can be improved.

[0109] In the above chemical formula 2, M 4 ... may be one or more doping elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo, or may be one or more doping elements selected from the group consisting of W, Y, Ba, Ca, Ti, Mg, Ta, and Nb. 4 It may be optionally included in or not included in the lithium nickel-based oxide represented by the above chemical formula 2, and if included, it may play a role in facilitating calcination or improving structural stability.

[0110] In the above chemical formula 2, 1+a1 may represent the molar ratio of lithium (Li) in the lithium nickel-based oxide, and may be 0.5≤1+a1≤1.5, 0.8≤1+a1≤1.5, 1.0≤1+a1≤1.5, 1.0≤1+a1≤1.2, 1.0≤1+a1≤1.1, or 1.0≤1+a1≤1.05. When the above range is satisfied, the positive electrode active material can form a stable layered crystal structure.

[0111] In the above chemical formula 2, x2 represents the molar ratio of nickel among the total metals excluding lithium in the lithium nickel-based oxide particles, and may be 0.60≤x2<1.0, 0.65≤x2<1.0, 0.70≤x2<1.0, 0.70≤x2≤0.90, 0.70≤x2≤0.80, or 0.70≤x2≤0.75. When the above range is satisfied, the capacity characteristics of the positive electrode active material may be excellent.

[0112] In the above Chemical Formula 2, y2 represents the molar ratio of cobalt among the total metals excluding lithium in the lithium nickel-based oxide particles, where 0 <y2≤0.3, 0<y2≤0.2, 0<y2≤0.15, 또는 0<y2≤0.1일 수 있다. 상기 범위를 만족하는 경우, 비용적인 이점을 가지면서, 출력 특성이 개선될 수 있다.

[0113] In the above chemical formula 2, z2 is M among the total metals excluding lithium in the lithium nickel-based oxide particles. 3 It refers to the molar ratio of, 0 <z2≤0.3, 0<z2≤0.25, 또는 0<z2≤0.2일 수 있다. 상기 범위를 만족하는 경우, 양극 활물질의 구조적 안정성이 개선될 수 있다.

[0114] In the above chemical formula 2, w2 is M among the total metals excluding lithium in the lithium nickel-based oxide particles. 4 It refers to the molar ratio of 0≤w2≤0.1, 0≤w2≤0.08, 0≤w2≤0.05, or 0≤w2≤0.01. When the above range is satisfied, it can play a role in promoting particle growth during calcination of the anode active material or improving crystal structure stability.

[0115]

[0116] The above-mentioned positive electrode active material may include a lithium nickel-based oxide containing nickel, cobalt, and manganese. For example, the above-mentioned positive electrode active material may include a lithium nickel-based oxide represented by the following chemical formula 2-1. When the above-mentioned lithium nickel-based oxide includes manganese, structural stability may be improved as the manganese contributes to maintaining the layered structure of the lithium nickel-based oxide.

[0117] [Chemical Formula 2-1]

[0118] Li 1+a2 [Ni x3 Co y3 Mn z3 M 4 w3 ]O2

[0119] In the above chemical formula 2-1, M 4 ... may be one or more doping elements selected from the group consisting of Al, W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo, or may be one or more doping elements selected from the group consisting of Al, W, Y, Ba, Ca, Ti, Mg, Ta, and Nb. 4 It may be optionally included in or not included in the lithium nickel-based oxide represented by the above chemical formula 2-1, and if included, it may play a role in facilitating sintering or improving structural stability.

[0120] In the above chemical formula 2-1, 1+a2 may represent the molar ratio of lithium (Li) in the lithium nickel-based oxide, and may be 0.5≤1+a2≤1.5, 1.0≤1+a2≤1.5, 1.0≤1+a2≤1.2, 1.0≤1+a2≤1.1, or 1.0≤1+a2≤0.05. When the above range is satisfied, the positive electrode active material can form a stable layered crystal structure.

[0121] In the above chemical formula 2-1, x3 represents the molar ratio of nickel among the total metals excluding lithium in the lithium nickel-based oxide particles, and may be 0.60≤x3<1.0, 0.65≤x3<1.0, 0.70≤x3<1.0, 0.70≤x3≤0.90, 0.70≤x3≤0.80, or 0.70≤x3≤0.75. When the above range is satisfied, the capacity characteristics of the positive electrode active material may be excellent.

[0122] In the above Chemical Formula 2-1, y3 represents the molar ratio of cobalt among the total metals excluding lithium in the lithium nickel-based oxide particles, where 0 <y3≤0.3, 0<y3≤0.2, 0<y3≤0.15, 또는 0<y3≤0.1일 수 있다. 상기 범위를 만족하는 경우, 비용적인 이점을 가지면서, 출력 특성이 개선될 수 있다.

[0123] In the above Chemical Formula 2-1, z3 represents the molar ratio of manganese among the total metals excluding lithium in the lithium nickel-based oxide particles, where 0 <z3≤0.3, 0<z3≤0.25, 또는 0<z3≤0.2일 수 있다. 상기 범위를 만족하는 경우, 양극 활물질의 구조적 안정성이 개선될 수 있다.

[0124] In the above chemical formula 2-1, w3 is M among the total metals excluding lithium in the lithium nickel-based oxide particles. 4 It refers to the molar ratio of 0≤w3≤0.1, 0≤w3≤0.08, 0≤w3≤0.05, or 0≤w3≤0.01. If the above range is satisfied, the structural stability of the positive electrode active material can be improved.

[0125]

[0126] The positive electrode active material according to the present invention has a ratio of average grain size (unit: nm) to the content of Ni (unit: mol%) among all metals excluding lithium to 1.9 nm / mol% to 3.0 nm / mol%.

[0127] As the nickel content in the cathode active material increases, the structural stability of the cathode active material may deteriorate. For example, this structural instability is primarily caused by the incorporation of nickel and lithium ions or structural transitions at high voltages due to the increased nickel content. Since the nickel content affects the internal structure of the cathode active material, it is necessary to optimally design the internal structure of the cathode active material according to the nickel content to improve structural stability in cathode active materials containing high nickel content.

[0128] Grain size is one of the factors determining the degree of grain boundary formation in cathode active materials. Since grain boundaries contain numerous structural defects, facilitate cation mixing, and easily serve as sites for oxygen desorption and crack initiation, they affect the structural stability of the cathode active material. Furthermore, the degree of stress relaxation during charging and discharging can vary depending on the grain size of the cathode active material, and it can also influence the diffusivity of lithium ions.

[0129] Therefore, by optimally designing the average grain size as an internal structure of the positive electrode active material according to the nickel content, the structural stability of the positive electrode active material and resistance characteristics can be improved.

[0130]

[0131] For example, the ratio of the average grain size (unit: nm) to the content of Ni (unit: mol%) among all metals excluding lithium may be 1.9 nm / mol% or more, 2.0 nm / mol% or more, 2.1 nm / mol% or more, 2.2 nm / mol% or more, 2.3 nm / mol% or more, 2.4 nm / mol% or more, 2.5 nm / mol% or more, 2.6 nm / mol% or more, 2.7 nm / mol% or more, 2.8 nm / mol% or more, 2.9 nm / mol% or more, 3.0 nm / mol% or less, 2.99 nm / mol% or less, 2.98 nm / mol% or less, or 2.97 nm / mol% or less. Alternatively, the ratio of the average grain size (unit: nm) to the content of Ni (unit: mol%) among the total metals excluding lithium may be 1.9 nm / mol% to 3.0 nm / mol%, 2.5 to 2.99 nm / mol%, or 2.9 to 2.98 nm / mol%. If the average grain size is excessively large compared to the nickel content in the cathode active material, cracks may occur within the grains during charging and discharging, which may lead to problems such as structural collapse and the formation of rock salt phases, and may increase resistance. In addition, if the average grain size is excessively small compared to the nickel content in the cathode active material, the crystallinity of the cathode active material is low, which may lead to problems such as reduced capacity development and structural stability.

[0132] Therefore, when the above range is satisfied, the cathode active material may have excellent crystallinity, excellent lithium ion diffusivity, and excellent resistance characteristics, capacity characteristics, and structural stability. Accordingly, the manufactured lithium secondary battery has the advantage of having excellent output characteristics and lifespan characteristics, as well as excellent capacity characteristics. Since the structural instability caused by nickel is more severe in cathode active materials in which the nickel content among the total metals excluding lithium is 60 mol% or more, 65 mol% or more, or 70 mol% to 80 mol%, the effect of improving resistance characteristics, capacity characteristics, and structural stability can be further maximized when the ratio of the average grain size (unit: nm) to the content of Ni among the total metals excluding lithium (unit: mol%) satisfies the above range.

[0133] The content of Ni among the total metals excluding the lithium mentioned above may be 60 mol% or more, 65 mol% or more, 70 mol% or more, 70 mol% to 90 mol%, 70 mol% to 80 mol%, or 70 mol% to 75 mol%. When the above range is satisfied, the cathode active material may have excellent energy density and improve structural stability.

[0134] The above average grain size may be 500 nm to 800 nm, 520 nm to 780 nm, 550 nm to 750 nm, or 600 nm to 700 nm. When the above range is satisfied, the crystal structure of the cathode active material becomes more stabilized, and high capacity characteristics can be achieved.

[0135] The above positive active material may have an I(003) / I(104) value measured by XRD of 1.0 to 2.0, 1.0 to 1.5, 1.0 to 1.3, 1.0 to 1.2, 1.1 to 1.2, or 1.182 to 1.19. When the above range is satisfied, the layered structure of the positive active material is stably formed, and the crystallinity of the positive active material can be secured above a certain level. Accordingly, the mixing of cations between lithium ions and nickel ions is low, resulting in excellent structural stability, reduced resistance, and excellent lifespan characteristics.

[0136]

[0137] The above positive active material has an average particle size D 50 This can be 10.0㎛ to 15.0㎛, 10.5㎛ to 14.0㎛, 11.0㎛ to 13.0㎛, or 11.2㎛ to 12.0㎛. When the above range is satisfied, the crystal structure of the positive active material can be stable and side reactions with the electrolyte can be minimized.

[0138]

[0139] The above positive active material may include secondary particles. In this case, it may have the effect of having excellent resistance, charge / discharge efficiency, and capacity characteristics.

[0140]

[0141] The above-mentioned positive electrode active material may comprise a calcined mixture of the aforementioned precursor for the positive electrode active material and a lithium raw material. The above-mentioned positive electrode active material may be manufactured by mixing the aforementioned precursor for the positive electrode active material and a lithium raw material and calcining them. Since the method of manufacturing the positive electrode active material is the same as described below, a detailed explanation is omitted.

[0142]

[0143] Method for manufacturing positive electrode active material

[0144] Referring to FIG. 1, the method for manufacturing a positive electrode active material according to the present invention comprises the step (100) of mixing a precursor for a positive electrode active material containing a nickel-based hydroxide containing 60 mol% or more of nickel among the total metals and a lithium raw material, and calcining to manufacture a positive electrode active material.

[0145]

[0146] The precursor for the positive electrode active material comprises a nickel-based hydroxide containing 60 mol% or more of nickel among the total metals. For example, the precursor for the positive electrode active material may comprise a nickel-based hydroxide containing 60 mol% or more, 65 mol% or more, 70 mol% or more, less than 100 mol%, 95 mol% or less, 90 mol% or less, 85 mol% or less, 80 mol% or less, 75 mol% or less, 72 mol% or less, or 70 mol% or less of nickel among the total metals. Alternatively, the precursor for the positive electrode active material may comprise a nickel-based hydroxide containing 60 mol% or more, 65 mol% or more, 70 mol% or more, 70 mol% to 90 mol%, 70 mol% to 80 mol%, or 70 mol% to 75 mol% of nickel among the total metals. Accordingly, the capacity characteristics of the positive electrode active material can be improved.

[0147] The above precursor for the positive electrode active material has a ratio of (101) plane grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal to 1.5 nm / mol% to 2.0 nm / mol%. When manufacturing a positive electrode active material using the above precursor for the positive electrode active material, the (101) plane grain size is controlled to a specific range in the pre-calcination stage, so that the ratio of the average grain size to the nickel content satisfies a specific range even without relatively increasing the calcination temperature. Even if the positive electrode active material has a nickel content of 60 mol% or more in the total metal excluding lithium, the rock salt phase formed on the surface is reduced and it can be manufactured to be structurally stable.

[0148]

[0149] Since the characteristics of the above-mentioned precursor for the positive electrode active material are the same as those previously described, a detailed explanation is omitted.

[0150]

[0151] The above-mentioned precursor for the cathode active material may be manufactured according to the following manufacturing method. When the precursor for the cathode active material is manufactured according to the following manufacturing method, the ratio of the (101) plane grain size (unit: nm) to the content of Ni in the total metal (unit: mol%) can be controlled within a specific range. Since the temperature of the reaction solution, the supply rate of the transition metal aqueous solution, and the pH of the reaction solution during the nucleation stage of the manufacturing method for the cathode active material, and the supply rate of the transition metal aqueous solution, the pH of the reaction solution, and the reaction time during the particle growth stage significantly affect the growth rate and internal structure of the precursor for the cathode active material, they can act as major factors in controlling the ratio of the (101) plane grain size (unit: nm) to the content of Ni in the total metal (unit: mol%).

[0152]

[0153] Referring to FIG. 2, the method for manufacturing a precursor for a positive electrode active material comprises: (1) a nucleation step (210) of forming a nucleus for a positive electrode active material by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound; and (2) a particle growth step (220) of growing a precursor particle for a positive electrode active material by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound while supplying them to the reaction solution in which the nucleus for a positive electrode active material is formed.

[0154]

[0155] (Nucleation stage)

[0156] First, a reaction solution containing a precursor nucleus for an anode active material can be formed by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound. For example, a reaction solution containing a precursor nucleus for an anode active material can be formed by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound while supplying them to a first reactor.

[0157] The first reactor mentioned above may be a batch reactor. This is because it is difficult to control the particle size of the precursor particles when manufacturing the precursor using a Continuous Stirred-Tank Reactor (CSTR).

[0158] The first reactor may include a reaction mother liquor. For example, before supplying the reaction raw materials, such as an aqueous solution of a transition metal, an ammonium cation complex forming agent, and a basic compound, the ammonium cation complex forming agent, the basic compound, and water may be first introduced into the first reactor to form a reaction mother liquor.

[0159] The ammonium cation complex forming agent may be at least one selected from the group consisting of NH4OH, (NH4)2SO4, NH4NO3, NH4Cl, CH3COONH4, and NH4CO3, and may be introduced into a reactor in the form of a solution in which the compound is dissolved in a solvent. At this time, the solvent may be water, or a mixture of water and an organic solvent that is uniformly miscible with water (e.g., alcohol).

[0160] The above basic compound may be at least one selected from the group consisting of NaOH, KOH, and Ca(OH)2, and may be introduced into the reactor in the form of a solution in which the compound is dissolved in a solvent. In this case, water or a mixture of water and an organic solvent that is uniformly miscible with water (e.g., alcohol) may be used as the solvent.

[0161] The above reaction mother liquor can be formed such that its pH is approximately 9.5 to 12.0, 10.0 to 11.8, or 10.0 to 11.5. When the pH of the reaction mother liquor satisfies the above range, nucleation can be carried out smoothly.

[0162] After forming a reaction mother liquor by introducing an ammonium cation complex forming agent, a basic compound, and water into a first reactor, oxygen in the reaction mother liquor can be removed by purging with nitrogen gas.

[0163]

[0164] Next, an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound are supplied to the first reactor, and a co-precipitation reaction is carried out while stirring to prepare a reaction solution in which precursor seeds are formed.

[0165] When a transition metal aqueous solution, an ammonium cation complex forming agent, and a basic compound are supplied to a first reactor containing a reaction mother liquor and stirred, a co-precipitation reaction proceeds, generating precursor nuclei in the form of primary particles, and as the nuclei in the form of primary particles aggregate, seed nuclei in the form of secondary particles are formed.

[0166] In the above nucleation step, the transition metal aqueous solution may be supplied at a flow rate of 0.1 L / h to 2 L / h, 0.2 L / h to 0.8 L / h, 0.3 L / h to 0.6 L / h, or 0.4 L / h to 0.5 L / h. The above flow rate may be the average flow rate value during the co-precipitation reaction. If the above range is satisfied, nuclei with an appropriate density gradient can be formed, and accordingly, it can contribute to controlling the crystal grain size in the (101) plane direction of the precursor for the anode active material.

[0167] In the above nucleation step, the ammonium cation complex forming agent may be supplied at a flow rate of 0.01 L / h to 1.50 L / h, 0.02 L / h to 1.20 L / h, 0.03 L / h to 1.00 L / h, or 0.05 L / h to 0.5 L / h. When the above ranges are satisfied, nuclei are formed smoothly, the growth rate of the nuclei can be maintained, and the degree of sphericity can be improved.

[0168] In the above nucleation step, the basic compound may be supplied at a flow rate of 0.5 L / h to 2.5 L / h, 1.0 L / h to 2.0 L / h, or 1.2 L / h to 1.8 L / h. If the above ranges are satisfied, the pH of the reaction solution can be maintained within an appropriate range.

[0169] The above transition metal aqueous solution is nickel, cobalt, and M 1 Element (M above) 1 It may include manganese, aluminum, or a combination thereof, nickel raw material, cobalt raw material and M 1 It can be formed by mixing raw materials with water.

[0170] The above nickel raw material may be Ni(OH)2, NiO, NiOOH, NiCO3·2Ni(OH)2·4H2O, NiC2O2·2H2O, Ni(NO3)2·6H2O, NiSO4, NiSO4·6H2O, nickel salts of fatty acids, or nickel halides, and any one or more of these may be used.

[0171] The above cobalt raw material may be Co(OH)2, CoOOH, Co(OCOCH3)2ㆍ4H2O, Co(NO3)2ㆍ6H2O, or Co(SO4)2ㆍ7H2O, etc., and any one or more of these may be used.

[0172] The above M 1In the case of manganese, the manganese raw material may be manganese oxides such as Mn2O3, MnO2, and Mn3O4; manganese salts such as MnCO3, Mn(NO3)2, MnSO4, manganese acetate, manganese dicarboxylate, manganese citrate, and manganese fatty acid salts; oxyhydroxide, or manganese chloride, and any one or more of these may be used.

[0173] The above M 1 In the case of aluminum, it may be an acetate, sulfate, sulfide, hydroxide, oxide, or oxyhydroxide containing the aluminum, and any one or more of these may be used.

[0174]

[0175] The above transition metal aqueous solution may contain a nickel raw material such that the nickel content is 60 mol% or more, 65 mol% or more, 70 mol% or more, 70 mol% to 90 mol%, 70 mol% to 80 mol%, or 70 mol% to 75 mol% with respect to the total molar amount of the transition metal. When the nickel content in the transition metal aqueous solution is 60 mol% or more, the capacity characteristics can be further improved.

[0176] The content of the transition metal included in the transition metal aqueous solution supplied in the above nucleation step may be 1.5 mol / L to 2.5 mol / L, or 1.8 mol / L to 2.3 mol / L.

[0177] If necessary, the above transition metal aqueous solution may further include doping elements in addition to nickel, cobalt, and manganese. In this case, the doping element may include at least one selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo. When the above positive active material further includes doping elements, the effect of improving lifespan characteristics, discharge characteristics, and / or stability can be achieved.

[0178] If the above transition metal aqueous solution further includes the above doping element, the raw material containing the above doping element may be optionally added during the preparation of the above transition metal aqueous solution.

[0179] As the raw material containing the doping element, at least one selected from the group consisting of acetates, sulfates, sulfides, hydroxides, oxides, or oxyhydroxides containing the doping element may be used.

[0180]

[0181] The above nucleation step may be performed for 2 to 20 hours, 3 to 15 hours, or 4 to 10 hours. If the nucleation time is too short, sufficient nuclei are not generated, which may reduce productivity and result in a non-uniform particle size distribution of the precursor particles. Additionally, if the nucleation time is too long, the reaction time required to grow the precursor particles to the desired particle size may become too long, which may reduce productivity and result in a non-uniform particle size distribution as some particles grow during the nucleation process.

[0182] In addition, the pH of the reaction solution in the nucleation step may be 9.0 to 12.0, 9.2 to 11.0, 9.5 to 10.5, 9.7 to 10.3, or 9.9 to 10.1. When the above range is satisfied, the internal structure of the nucleus of the precursor for the positive active material is controlled, which can contribute to controlling the (101) plane crystal grain size of the precursor for the positive active material. In addition, the process of forming nuclei of the positive active material precursors within the reaction solution and the nuclei aggregating to form larger nuclei can be carried out smoothly. The pH of the reaction solution can be controlled by controlling the amount of basic compound added using a pH sensor, etc.

[0183] In the above nucleation step, the temperature of the reaction solution may be 40°C to 80°C, 45°C to 80°C, 50°C to 78°C, 60°C to 75°C, or 65°C to 70°C. When the temperature of the reaction solution satisfies the above range, the nucleation of the precursor for the positive active material can be facilitated, and as the internal structure of the nucleus of the precursor for the positive active material is controlled, it can contribute to controlling the crystal grain size in the (101) plane direction of the precursor for the positive active material.

[0184]

[0185] When the reaction is completed after sufficient nuclei of the precursor for the positive electrode active material are formed in the above nucleation step, the reaction solution can be transferred from the first reactor to the second reactor. When the reaction solution is transferred from the first reactor to the second reactor to perform the particle growth step described later, the flow rate of the transition metal aqueous solution can be easily controlled, thereby reducing the particle growth rate of the precursor. Accordingly, the ratio of the (101) plane crystal size (unit: nm) to the content of Ni (unit: mol%) among the total metals in the manufactured precursor for the positive electrode active material can be appropriately controlled.

[0186]

[0187] (Particle growth stage)

[0188] When nuclei are sufficiently formed through the above process, precursor particles for the positive active material can be grown by co-precipitating a reaction solution in which the precursor nuclei for the positive active material are formed, while supplying an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound. For example, after moving the reaction solution from the first reactor to the second reactor, precursor particles for the positive active material can be grown by co-precipitating a reaction solution in the second reactor in which the precursor nuclei for the positive active material are formed, while supplying an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound.

[0189]

[0190] The supply rate of the ammonium cation complex forming agent may be 0.1 L / h to 0.5 L / h, 0.1 L / h to 0.3 L / h, or 0.1 L / h to 0.2 L / h. When the above range is satisfied, the crystal growth rate of the precursor can be controlled to an appropriate range, and accordingly, it can contribute to the production of a precursor for a positive electrode active material in which the ratio of the (101) plane grain size (unit: nm) to the content of Ni in the total metal (unit: mol%) satisfies a specific range.

[0191] The supply rate of the above transition metal aqueous solution may be 0.1 L / h to 2.0 L / h, 0.1 L / h to 1.5 L / h, 0.2 L / h to 1.2 L / h, 0.3 L / h to 1.0 L / h, or 0.5 L / h to 0.7 L / h. When the above range is satisfied, the crystal growth rate of the precursor can be controlled to an appropriate range, and accordingly, this can contribute to the production of a precursor for a positive electrode active material in which the ratio of the (101) plane grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal satisfies a specific range.

[0192]

[0193] The transition metal aqueous solution, ammonium cation complex forming agent, and basic compound introduced during the particle growth stage are the same as those used during the nucleation stage.

[0194]

[0195] In the particle growth step, before supplying the transition metal aqueous solution, ammonium cation complex forming agent, and basic compound to the reaction solution, the reaction solution may be purged with an inert gas, such as nitrogen (N2), to remove dissolved oxygen and create a non-oxidizing atmosphere inside the reactor.

[0196] The above inert gas may be supplied to the reactor at a rate of 100 L / h to 500 L / h, 200 L / h to 400 L / h, or 250 L / h to 350 L / h. If the above range is satisfied, the crystallinity of the precursor for the cathode active material can be improved.

[0197]

[0198] The above particle growth step can be performed in a nitrogen atmosphere. Accordingly, the crystallinity of the precursor can be appropriately controlled.

[0199] The pH at which the co-precipitation reaction occurs during the particle growth step is 9.5 to 10.3, 9.7 to 10.27, 9.9 to 10.25, or 10.1 to 10.2. When the pH of the reaction solution satisfies the above range, the crystal growth rate of the precursor can be controlled to an appropriate range, and accordingly, a precursor for a positive electrode active material can be manufactured in which the ratio of the (101) plane crystal size (unit: nm) to the content of Ni in the total metal (unit: mol%) satisfies a specific range. The pH of the reaction solution can be controlled by controlling the amount of basic compound added using a pH sensor, etc.

[0200] During the co-precipitation reaction in the particle growth step, the stirring speed may be 200 rpm to 400 rpm, 220 rpm to 380 rpm, 250 rpm to 350 rpm, or 280 rpm to 320 rpm. If the above range is satisfied, the crystal growth rate of the precursor can be controlled to an appropriate range, and accordingly, this can contribute to the production of a precursor for a positive electrode active material in which the ratio of the (101) plane crystal size (unit: nm) to the content of Ni in the total metal (unit: mol%) satisfies a specific range.

[0201] In the particle growth step above, the co-precipitation reaction can be carried out at a temperature of 40°C to 80°C, 45°C to 80°C, or 45°C to 75°C. If the temperature of the co-precipitation reaction satisfies the above range, particle growth can be carried out smoothly.

[0202] In the particle growth step above, the reaction for growing precursor particles for the positive electrode active material may be carried out for 7 to 100 hours, 8 to 90 hours, 10 to 80 hours, 30 to 70 hours, 40 to 50 hours, or 43 to 46 hours. When the above range is satisfied, precursor particles for the positive electrode active material can be obtained by growing the precursor particles for the positive electrode active material to an appropriate size, while controlling the ratio of the (101) plane crystal size (unit: nm) to the content of Ni in the total metal (unit: mol%) to the desired range.

[0203]

[0204] When the precursor particles for the positive electrode active material have grown sufficiently through the above process, the precursor particles can be separated from the reaction solution, washed, and dried to obtain the precursor particles for the positive electrode active material.

[0205] The above drying can be performed at 80°C to 200°C, 100°C to 180°C, or 120°C to 160°C.

[0206] The above drying may be performed for 50 hours or less, 30 hours or less, or 10 to 15 hours or less.

[0207]

[0208] The above sintering may be obtained by a sintering method known in the art, and the method is not particularly limited.

[0209] The above lithium raw materials may include lithium-containing carbonates (e.g., lithium carbonate, etc.), hydrates (e.g., lithium hydroxide hydrate (LiOH·H2O), etc.), hydroxides (e.g., lithium hydroxide, etc.), nitrates (e.g., lithium nitrate (LiNO3), etc.), chlorides (e.g., lithium chloride (LiCl), etc.), and one of these alone or a mixture of two or more may be used.

[0210] The mixing of the precursor particles for the positive electrode active material and the lithium raw material can be carried out by solid-state mixing such as jet milling. The mixing ratio of the precursor particles for the positive electrode active material and the lithium raw material can be determined within a range that satisfies the mole fraction of each component in the positive electrode active material finally manufactured. For example, the precursor particles for the positive electrode active material and the lithium raw material may be mixed such that the lithium element in the precursor particles for the positive electrode active material and the lithium raw material is in a molar ratio of 1:1.0 to 1:1.5 or 1:1.0 to 1:1.3.

[0211] Although not essential, in addition to the precursor for the cathode active material and the lithium raw material, raw materials for doping some of the transition metals and / or oxygen of the cathode active material may be additionally included in the above mixture. For example, the raw material containing the doping element described above may be additionally mixed in the above mixture.

[0212] The above calcination can be performed at a temperature of 600°C to 900°C, 700°C to 880°C, or 800°C to 860°C. When calcined within the above temperature range, the calcination temperature is not excessively high, thereby suppressing the formation of rock salt phases on the surface of the positive electrode active material or the occurrence of oxygen desorption. The method for manufacturing a positive electrode active material according to the present invention manufactures a positive electrode active material by calcining a precursor for a positive electrode active material in which the ratio of the (101) plane direction grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal is 1.5 nm / mol% to 2.0 nm / mol%. Therefore, even when calcined within the above temperature range, a positive electrode active material having sufficient structural stability can be manufactured.

[0213] The above calcination can be performed for 5 to 20 hours, 7 to 15 hours, or 8 to 12 hours. When calcined within the above time range, the calcination is performed within an appropriate time, allowing the positive active material to grow sufficiently and the layered structure to be formed smoothly.

[0214]

[0215] The positive active material manufactured accordingly is the same as previously described, so a detailed explanation is omitted.

[0216]

[0217] anode

[0218] The anode according to the present invention comprises the aforementioned anode active material. For example, the anode may comprise an anode active material layer comprising the aforementioned anode active material, or may comprise an anode current collector; and an anode active material layer located on the anode current collector and comprising the aforementioned anode active material.

[0219]

[0220] Hereinafter, each component of the anode according to the present invention will be described.

[0221]

[0222] (1) Positive current collector

[0223] Various positive current collectors used in the relevant technical field may be used as the positive current collector. For example, the positive current collector may be stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface treated with carbon, nickel, titanium, silver, etc. The positive current collector may typically have a thickness of 3 μm to 500 μm, and fine irregularities may be formed on the surface of the positive current collector to increase the adhesion of the positive active material. The positive current collector may be used in various forms, such as a film, sheet, foil, net, porous body, foam, nonwoven fabric, etc.

[0224]

[0225] (2) Positive active material layer

[0226] The positive active material layer may be located on the positive current collector, for example, on one or both sides of the positive current collector. The positive active material layer may be a single layer or a multilayer structure of two or more layers.

[0227] The above positive active material layer may include a positive active material, a positive conductive material, and a positive binder.

[0228] Since the above-mentioned positive active material is identical to the positive active material according to the present invention described above, the characteristics of the above-mentioned positive active material are identical to those described above.

[0229]

[0230] The above positive active material may be included in an amount of 90% to 99% by weight, 92% to 98% by weight, or 94% to 98% by weight based on the total weight of the positive active material layer. If the above range is satisfied, the energy density and capacity characteristics of the lithium secondary battery to which the positive material is applied can be improved.

[0231] The above-mentioned positive electrode conductive material is used to impart conductivity to the electrode, and in the battery being constructed, it may be used without special limitations as long as it possesses electronic conductivity without causing chemical changes. 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, carbon nanotube; metal powder or metal fiber such as copper, nickel, aluminum, or silver; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and one of these alone or a mixture of two or more may be used. The above-mentioned positive electrode conductive material may typically be included in an amount of 0.1% to 10% by weight, 0.5% to 8% by weight, or 1% to 4% by weight based on the total weight of the positive electrode active material layer.

[0232] The above-mentioned anode binder serves to improve adhesion between anode active material particles and adhesion between the anode active material and the anode current collector, and is, for example, a fluoropolymer-based binder comprising polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); a rubber-based binder comprising styrene butadiene rubber (SBR), acrylonitrile-butadiene rubber, or styrene-isoprene rubber; a cellulose-based binder comprising carboxyl methyl cellulose (CMC), starch, hydroxypropyl cellulose, or regenerated cellulose; a polyalcohol-based binder comprising polyvinyl alcohol; a polyolefin-based binder comprising polyethylene or polypropylene; a polyimide-based binder; or a polyester-based binder. Examples include silane-based binders, and one of these alone or a mixture of two or more may be used. The anode binder may be included in an amount of 0.1% to 10% by weight, 0.5% to 10% by weight, or 1% to 4% by weight based on the total weight of the anode active material layer.

[0233]

[0234] The anode may be manufactured by methods known in the art. For example, the anode may be manufactured by mixing an anode active material, an anode binder, and an anode conductive material in a solvent to prepare an anode slurry, applying the anode slurry onto an anode current collector, and then drying and rolling, or by casting the anode slurry onto a separate support and then laminating the film obtained by peeling it off from the support onto an anode current collector. In this case, the solvent for the anode slurry may be any anode slurry solvents generally used in the art, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, or a mixture thereof, but is not limited thereto. The solvent may be used in an amount that dissolves or disperses the anode active material, the anode conductive material, and the anode binder, and has a viscosity such that the anode slurry can be uniformly coated.

[0235]

[0236] lithium secondary battery

[0237] A lithium secondary battery according to the present invention is described. The lithium secondary battery according to the present invention comprises a positive electrode according to the present invention; a negative electrode disposed opposite to the positive electrode; and an electrolyte. Optionally, the lithium secondary battery according to the present invention may further comprise a separator interposed between the positive electrode and the negative electrode.

[0238] Since the anode above is the same as described above, the remaining components excluding the anode will be described below.

[0239]

[0240] (1) Cathode

[0241] In a lithium secondary battery according to the present invention, the negative electrode comprises a negative electrode active material layer including a negative electrode active material, and, for example, may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0242]

[0243] The above-mentioned negative 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., and aluminum-cadmium alloy may be used. In addition, the above-mentioned negative current collector may typically have a thickness of 3 μm to 500 μm, and, similar to the positive current collector, fine irregularities may be formed on the surface of the current collector to strengthen the bonding strength of the negative active material. For example, it may be used in various forms such as a film, sheet, foil, net, porous body, foam, nonwoven fabric, etc.

[0244]

[0245] The above negative electrode active material layer may be located on the negative electrode current collector, for example, on one or both sides of the negative electrode current collector. The above negative electrode active material layer may have a single-layer structure or a multi-layer structure of two or more layers.

[0246] When the negative electrode active material layer is a multilayer structure composed of two or more layers, the types and / or contents of the negative electrode active material, negative electrode binder, and / or negative electrode conductive material in each layer may differ from one another. By forming the negative electrode active material layer into a multilayer structure and varying the composition of each layer, the performance characteristics of the battery, such as rapid charging performance and output characteristics, can be appropriately controlled.

[0247] As the above-mentioned negative electrode active material, a compound capable of reversible intercalation and deintercalation of lithium may be used. For example, 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 alloys, Sn alloys, or Al alloys; SiO β Examples include metal oxides capable of doping and dedoping lithium, such as (0 < β < 2), SnO2, vanadium oxide, and lithium vanadium oxide; or composites comprising the metal compound and carbonaceous material, such as Si-C composites or Sn-C composites, and any one or more of these may be used.

[0248] The above carbonaceous materials may include both low-crystallinity carbon and high-crystallinity carbon. Low-crystallinity carbon may include soft carbon and hard carbon, while high-crystallinity carbon may include amorphous, plate-like, flake-like, spherical, or fibrous natural or artificial graphite, Kish graphite, pyrolytic carbon, mesophase pitch-based carbon fiber, meso-carbon microbeads, mesophase pitches, and high-temperature calcined carbon such as petroleum or coal tar pitch-derived cokes.

[0249] Alternatively, the cathode active material may be a carbon-based cathode active material, wherein the carbon-based cathode active material may include, for example, natural graphite, artificial graphite, graphitized carbon fiber, amorphous carbon, soft carbon, hard carbon, or a combination thereof. Alternatively, the carbon-based cathode active material may include natural graphite and artificial graphite.

[0250] The above carbon-based negative electrode active material may have an average particle size D50 of 2㎛ to 30㎛, or about 5㎛ to 30㎛.

[0251] The above-mentioned negative electrode active material may be included in an amount of 80% to 98% by weight, 90% to 98% by weight, or 93% to 98% by weight based on the total weight of the negative electrode active material layer. When the content of the negative electrode active material satisfies the above range, excellent energy density can be achieved.

[0252]

[0253] The above cathode active material layer may further include a cathode conductive material and / or a cathode binder together with the cathode active material.

[0254] The cathode conductive material is used to impart conductivity to the cathode, and in the battery being constructed, it can be used without special restrictions as long as it has electronic conductivity without causing chemical changes. Examples include carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, carbon fiber, carbon nanotube; metal powders or metal fibers such as copper, nickel, aluminum, silver; conductive whiskers such as zinc oxide, potassium titanate; conductive metal oxides such as titanium oxide; or conductive polymers such as polyphenylene derivatives, and one of these alone or a mixture of two or more of them may be used.

[0255] The above-mentioned cathode conductive material may typically be included in an amount of 0.1% to 10% by weight, 0.1% to 8% by weight, or 0.1% to 5% by weight based on the total weight of the cathode active material layer.

[0256] The above-mentioned cathode binder serves to improve adhesion between cathode active material particles and adhesion between the cathode active material and the cathode current collector. Examples include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, 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 alone or a mixture of two or more may be used.

[0257] The above-mentioned cathode binder may be included in an amount of 0.1% to 10% by weight, 0.5% to 10% by weight, or 1% to 8% by weight based on the total weight of the cathode active material layer.

[0258]

[0259] The above cathode may be manufactured by methods known in the art. For example, the cathode may be manufactured by mixing a cathode active material, a cathode binder, and / or a cathode conductive material in a solvent to prepare a cathode slurry, applying the cathode slurry onto a cathode current collector, and then drying and rolling, or by casting the cathode slurry onto a separate support and then laminating the film obtained by peeling it off from the support onto a cathode current collector.

[0260] Meanwhile, solvents commonly used in the relevant technical field may be used as the solvent for the cathode slurry, for example, dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, water, or mixtures thereof, but are not limited thereto. The solvent may be used in an amount that dissolves or disperses the cathode active material, cathode conductive material, and cathode binder, and has a viscosity such that the cathode slurry can be uniformly coated.

[0261]

[0262] (2) Electrolyte

[0263] The electrolyte according to the present invention may include a lithium salt and an organic solvent.

[0264] The above lithium salt can be used without special restrictions as long as it is a compound capable of providing lithium ions used in lithium secondary batteries. For example, the above lithium salt may be LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAlO4, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2, LiCl, LiI, or LiB(C2O4)2. The concentration of the above lithium salt is preferably used within the range of about 0.1M to 5.0M or 0.1M to 3.0M. When the concentration of the lithium salt falls within the above range, the electrolyte has appropriate conductivity and viscosity, so it can exhibit excellent electrolyte performance and lithium ions can move effectively.

[0265]

[0266] The above organic solvent may include at least one of a cyclic carbonate-based organic solvent, a linear carbonate-based organic solvent, a linear ester-based organic solvent, and a cyclic ester-based organic solvent.

[0267] The above-mentioned cyclic carbonate-based organic solvent is a high-viscosity organic solvent that has a high dielectric constant and can effectively dissociate lithium salts in the electrolyte, and for example, it may be a non-fluorinated saturated cyclic carbonate-based organic solvent. The above-mentioned cyclic carbonate-based organic solvent may include at least one organic solvent selected from the group consisting of ethylene carbonate (EC), fluoroethylene carbonate (FEC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, and vinylene carbonate, and for example, it may include at least one selected from the group consisting of ethylene carbonate (EC) and fluoroethylene carbonate (FEC), or it may include ethylene carbonate (EC).

[0268] In addition, the linear carbonate-based organic solvent may be an organic solvent having low viscosity and low dielectric constant, for example, a non-fluorinated linear carbonate. The linear carbonate-based solvent may include at least one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethylmethyl carbonate (EMC), methylpropyl carbonate, and ethylpropyl carbonate, or may include at least one selected from the group consisting of ethylmethyl carbonate (EMC) and diethyl carbonate (DEC), or may include ethylmethyl carbonate (EMC).

[0269] The above linear ester-based organic solvent may include, for example, at least one organic solvent selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, and butyl propionate.

[0270] The above-mentioned cyclic ester-based organic solvent may include at least one organic solvent selected from the group consisting of butyrolactone, valerolactone, and caprolactone.

[0271] Alternatively, the electrolyte according to the present invention may include ethylene carbonate and dimethyl carbonate as organic solvents.

[0272]

[0273] Meanwhile, in addition to the electrolyte components, the above electrolyte may additionally include other additives for the purpose of improving the lifespan characteristics of the battery, suppressing the reduction of battery capacity, and improving the discharge capacity of the battery.

[0274] The above additive may include, for example, at least one additive selected from the group consisting of non-fluorinated unsaturated cyclic carbonate compounds, halogen-substituted carbonate compounds, sulfone compounds, sulfate compounds, borate compounds, nitrile compounds, benzene compounds, amine compounds, silane compounds, and lithium salt compounds different from the lithium salt included in the electrolyte.

[0275] For example, the above additive is vinylene carbonate (VC), vinylethylene carbonate, fluoroethylene carbonate (FEC), 1,3-propane sulfone (PS), 1,4-butane sulfone, ethene sulfone, 1,3-propene sulfone (PRS), 1,4-butene sulfone, 1-methyl-1,3-propene sulfone, ethylene sulfate (ESA), trimethylene sulfate (TMS), methyl trimethylene sulfate (MTMS), tetraphenyl borate, lithium oxalyl difluoroborate, succinonitrile, adiponitrile, acetonitrile, propionitrile, butyronitrile, valeronitrile, caprylonitrile, heptanitrile, cyclopentane carbonitrile, cyclohexane carbonitrile, Examples include one or more compounds selected from the group consisting of 2-fluorobenzonitrile, 4-fluorobenzonitrile, difluorobenzonitrile, trifluorobenzonitrile, phenylacetonitrile, 2-fluorophenylacetonitrile, 4-fluorophenylacetonitrile, fluorobenzene, triethanolamine, ethylenediamine, tetravinylsilane, LiN(SO2F)2 (Lithium bis(fluorosulfonyl)imide, LiFSI), LiN(SO2CF3)2 (lithium bis(trifluoromethane sulfonyl)imide, LiTFSI), LiPO2F2, LiODFB, LiBOB (lithium bis-oxalate toborate (LiB(C2O4)2)) and LiBF4.

[0276] The above additives may be included in an amount of 0.01% to 20% by weight based on the total weight of the electrolyte, or in an amount of 0.05% to 5.0% by weight. When the above range is satisfied, the low-temperature output of the battery, high-temperature storage characteristics, and high-temperature life characteristics can be improved, side reactions in the electrolyte can be reduced, and the presence of the additives as unreacted substances can be suppressed.

[0277]

[0278] (3) Separator

[0279] The above separator physically separates the negative electrode and the positive electrode and provides a pathway for the movement of lithium ions; any separator typically used in lithium secondary batteries can be used without any special restrictions. In this case, the separator may be interposed between the positive electrode and the negative electrode.

[0280] As the above separator, a porous polymer film made of a polyolefin-based 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, such as a nonwoven fabric made of high-melting-point glass fibers or polyethylene terephthalate fibers, may be used. Furthermore, a coated separator containing a ceramic component or a polymer material may be used to ensure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure.

[0281]

[0282] The lithium secondary battery according to the present invention as described above can be usefully applied to portable devices such as mobile phones, laptop computers, and digital cameras, as well as electric vehicles such as hybrid electric vehicles (HEVs). Since the lithium secondary battery according to the present invention exhibits excellent thermal stability and can realize excellent capacity characteristics, it can be usefully utilized in the field of electric vehicles.

[0283] According to another embodiment of the present invention, a battery module comprising a lithium secondary battery according to the present invention as a unit cell and a battery pack comprising the same are provided.

[0284] The above battery module or battery pack can be used as a power source for one or more medium-to-large devices, including a power tool; an electric vehicle (EV), a hybrid electric vehicle, and a plug-in hybrid electric vehicle (PHEV); or a power storage system.

[0285]

[0286] The present invention will be explained below through examples. However, the following examples are intended only to enable a person skilled in the art to fully understand and easily implement the present invention, and the scope of the present invention is not limited to the following examples.

[0287]

[0288] Preparation Example

[0289] Preparation Example 1

[0290] (1) Nucleation stage

[0291] NiSO4, CoSO4, and MnSO4 were dissolved in ion-exchanged water in amounts such that the molar ratio of nickel:cobalt:manganese was 7:1:2 to prepare a transition metal aqueous solution with a concentration of 2.0 M. Distilled water, ammonia water with a concentration of 9 wt%, and a sodium hydroxide aqueous solution with a concentration of 25 wt% were filled into a 10 L batch reactor (first reactor), and the temperature of the first reactor was increased while purging with N2 gas and stirring at 300 rpm.

[0292] When the internal solution temperature of the first reactor reaches 70℃, the transition metal aqueous solution is quantitatively injected at a supply rate of 0.4 L / h and ammonia solution with a concentration of 20 wt% is injected at a supply rate of 0.1 L / h, and an aqueous sodium hydroxide solution is injected using a pH peristaltic pump to maintain the reaction solution pH at 10.0. In the nucleation step, the reaction is carried out for approximately 5 hours, and the average particle size D of the prepared nuclei 50This was performed to make the size approximately 4.5 μm. The reaction solution in which the nuclei were formed was transferred from the first reactor to the second reactor.

[0293] (2) Particle growth stage

[0294] Next, the transition metal aqueous solution was supplied to the reaction solution in which the precursor nuclei for the cathode active material were formed in the second reactor at a supply rate of 0.7 L / h and the ammonia solution at a concentration of 9 wt% was supplied at a supply rate of 0.1 L / h; an aqueous sodium hydroxide solution was injected using a pH peristaltic pump to maintain the reaction solution pH at 10.2, and the co-precipitation reaction was carried out at 300 rpm. The average particle size D of the precursor particles for the cathode active material. 50 The reaction was terminated when it reached 12.3 μm, and the total reaction time was 45 hours.

[0295] After separating the precursor particles from the reaction solution, impurities were removed by washing, and the precursor for the cathode active material was prepared by drying in a drying oven at a temperature of 140°C for 12 hours and then sieving.

[0296]

[0297] Preparation Example 2

[0298] (1) Nucleation stage

[0299] NiSO4, CoSO4, and MnSO4 were dissolved in ion-exchanged water in amounts such that the molar ratio of nickel:cobalt:manganese was 7:1:2 to prepare a transition metal aqueous solution with a concentration of 2.0 M. Distilled water, ammonia water with a concentration of 9 wt%, and a sodium hydroxide aqueous solution with a concentration of 25 wt% were filled into a 10 L batch reactor (first reactor), and the temperature of the first reactor was increased while purging with N2 gas and stirring at 300 rpm.

[0300] When the internal solution temperature of the first reactor reaches 65℃, the transition metal aqueous solution is quantitatively injected at a supply rate of 0.4 L / h and ammonia water with a concentration of 20 wt% is injected at a supply rate of 0.1 L / h, and an aqueous sodium hydroxide solution is injected using a pH peristaltic pump to maintain the reaction solution pH at 10.0. In the nucleation step, the reaction is carried out for approximately 5 hours, and the average particle size D of the prepared nuclei 50 This was performed to make the size approximately 4.5 μm. The reaction solution in which the nuclei were formed was transferred from the first reactor to the second reactor.

[0301] (2) Particle growth stage

[0302] Next, the transition metal aqueous solution was supplied to the reaction solution in which the precursor nuclei for the cathode active material were formed in the second reactor at a supply rate of 0.7 L / h and the ammonia solution at a concentration of 9 wt% was supplied at a supply rate of 0.1 L / h; an aqueous sodium hydroxide solution was injected using a pH peristaltic pump to maintain the reaction solution pH at 10.2, and the co-precipitation reaction was carried out at 300 rpm. The average particle size D of the precursor particles for the cathode active material. 50 The reaction was terminated when it reached 12.3 μm, and the total reaction time was 44 hours.

[0303] After separating the precursor particles from the reaction solution, impurities were removed by washing, and the precursor for the cathode active material was prepared by drying in a drying oven at a temperature of 140°C for 12 hours and then sieving.

[0304]

[0305] Preparation Example 3

[0306] (1) Nucleation stage

[0307] NiSO4, CoSO4, and MnSO4 were dissolved in ion-exchanged water in amounts such that the molar ratio of nickel:cobalt:manganese was 7:1:2 to prepare a transition metal aqueous solution with a concentration of 2.0 M. Distilled water, ammonia water with a concentration of 9 wt%, and a sodium hydroxide aqueous solution with a concentration of 25 wt% were filled into a 10 L batch reactor (first reactor), and the temperature of the first reactor was increased while purging with N2 gas and stirring at 300 rpm.

[0308] When the internal solution temperature of the reactor reaches 65℃, the transition metal aqueous solution is quantitatively injected at a supply rate of 0.4 L / h and ammonia solution with a concentration of 20 wt% is injected at a supply rate of 0.1 L / h, and an aqueous sodium hydroxide solution is injected using a pH peristaltic pump to maintain the reaction solution pH at 10.4. In the nucleation step, the reaction is carried out for approximately 5 hours, and the average particle size D of the prepared nuclei 50 This was performed to make the size approximately 4.5 μm. The reaction solution in which the nuclei were formed was transferred from the first reactor to the second reactor.

[0309] (2) Particle growth stage

[0310] Next, the transition metal aqueous solution was supplied to the reaction solution in which the precursor nuclei for the cathode active material were formed in the second reactor at a supply rate of 0.7 L / h and the ammonia solution with a concentration of 9 wt% was supplied at a supply rate of 0.1 L / h; an aqueous sodium hydroxide solution was injected using a pH peristaltic pump to maintain the pH of the reaction solution at 10.6, and the co-precipitation reaction was carried out at 300 rpm. The average particle size D of the precursor particles for the cathode active material. 50 The reaction was terminated when it reached 12.4 μm, and the total reaction time was 47 hours.

[0311] After separating the precursor particles from the reaction solution, impurities were removed by washing, and the precursor for the cathode active material was prepared by drying in a drying oven at a temperature of 140°C for 12 hours and then sieving.

[0312]

[0313] Preparation Example 4

[0314] (1) Nucleation stage

[0315] NiSO4, CoSO4, and MnSO4 were dissolved in ion-exchanged water in amounts such that the molar ratio of nickel:cobalt:manganese was 7:1:2 to prepare a transition metal aqueous solution with a concentration of 2.0 M. Distilled water, ammonia water with a concentration of 9 wt%, and a sodium hydroxide aqueous solution with a concentration of 25 wt% were filled into a 10 L batch reactor (first reactor), and the temperature of the first reactor was increased while purging with N2 gas and stirring at 300 rpm.

[0316] When the internal solution temperature of the first reactor reaches 70℃, the transition metal aqueous solution is quantitatively injected at a supply rate of 0.4 L / h and ammonia solution with a concentration of 20 wt% is injected at a supply rate of 0.1 L / h, and an aqueous sodium hydroxide solution is injected using a pH peristaltic pump to maintain the reaction solution pH at 10.2. In the nucleation step, the reaction is carried out for approximately 5 hours, and the average particle size D of the prepared nuclei 50 This was performed to make the size approximately 4.5 μm. The reaction solution in which the nuclei were formed was transferred from the first reactor to the second reactor.

[0317] (2) Particle growth stage

[0318] Next, the transition metal aqueous solution was supplied to the reaction solution in which the precursor nuclei for the cathode active material were formed in the second reactor at a supply rate of 0.7 L / h and the ammonia solution at a concentration of 9 wt% was supplied at a supply rate of 0.1 L / h; an aqueous sodium hydroxide solution was injected using a pH peristaltic pump to maintain the pH of the reaction solution at 10.4, and the co-precipitation reaction was carried out at 300 rpm. The average particle size D of the precursor particles for the cathode active material. 50 The reaction was terminated when it reached 12.0 μm, and the total reaction time was 48 hours.

[0319] After separating the precursor particles from the reaction solution, impurities were removed by washing, and the precursor for the cathode active material was prepared by drying in a drying oven at a temperature of 140°C for 12 hours and then sieving.

[0320]

[0321] Preparation Example 5

[0322] (1) Nucleation stage

[0323] NiSO4, CoSO4, and MnSO4 were dissolved in ion-exchanged water in amounts such that the molar ratio of nickel:cobalt:manganese was 7:1:2 to prepare a transition metal aqueous solution with a concentration of 2.0 M. Distilled water, ammonia water with a concentration of 9 wt%, and a sodium hydroxide aqueous solution with a concentration of 25 wt% were filled into a 10 L batch reactor (first reactor), and the temperature of the first reactor was increased while purging with N2 gas and stirring at 300 rpm.

[0324] When the internal solution temperature of the first reactor reaches 60℃, the transition metal aqueous solution is quantitatively injected at a supply rate of 0.4 L / h and ammonia water with a concentration of 20 wt% is injected at a supply rate of 0.1 L / h, and an aqueous sodium hydroxide solution is injected using a pH peristaltic pump to maintain the reaction solution pH at 10.0. In the nucleation step, the reaction is carried out for approximately 5 hours, and the average particle size D of the prepared nuclei 50 This was performed to make the size approximately 4.5 μm. The reaction solution in which the nuclei were formed was transferred from the first reactor to the second reactor.

[0325] (2) Particle growth stage

[0326] Next, in the second reactor, the supply rate of the transition metal aqueous solution and the supply rate of the 9 wt% concentration ammonia solution were maintained at 0.7 L / h and 0.1 L / h, respectively, to the reaction solution in which the precursor nuclei for the cathode active material were formed; an aqueous sodium hydroxide solution was injected using a pH peristaltic pump to maintain the pH of the reaction solution at 10.2, and the co-precipitation reaction was carried out at 300 rpm. The average particle size D of the precursor particles for the cathode active material. 50The reaction was terminated when it reached 12.0 μm, and the total reaction time was 41 hours.

[0327] After separating the precursor particles from the reaction solution, impurities were removed by washing, and the precursor for the cathode active material was prepared by drying in a drying oven at a temperature of 140°C for 12 hours and then sieving.

[0328]

[0329] Preparation Example 6

[0330] (1) Nucleation stage

[0331] NiSO4, CoSO4, and MnSO4 were dissolved in ion-exchanged water in amounts such that the molar ratio of nickel:cobalt:manganese was 7:1:2 to prepare a transition metal aqueous solution with a concentration of 2.0 M. Distilled water, ammonia water with a concentration of 9 wt%, and a sodium hydroxide aqueous solution with a concentration of 25 wt% were filled into a 10 L batch reactor (first reactor), and the temperature of the first reactor was increased while purging with N2 gas and stirring at 300 rpm.

[0332] When the internal solution temperature of the first reactor reaches 65℃, the transition metal aqueous solution is quantitatively injected at a supply rate of 0.5 L / h and ammonia water with a concentration of 20 wt% is injected at a rate of 0.1 L / h, and an aqueous sodium hydroxide solution is injected using a pH peristaltic pump to maintain the reaction solution pH at 9.8. In the nucleation step, the reaction is carried out for approximately 5 hours, and the average particle size D of the prepared nuclei 50 This was performed to make the size approximately 4.5 μm. The reaction solution in which the nuclei were formed was transferred from the first reactor to the second reactor.

[0333] (2) Particle growth stage

[0334] Next, in the second reactor, the supply rate of the transition metal aqueous solution and the supply rate of ammonia water with a concentration of 9 wt% were maintained at 0.8 L / h and 0.1 L / h, respectively, and an aqueous sodium hydroxide solution was injected using a pH peristaltic pump to maintain the pH of the reaction solution at 9.6, and the co-precipitation reaction was carried out at 300 rpm. The average particle size D of the precursor particles for the cathode active material. 50 The reaction was terminated when it reached 12.3 μm, and the total reaction time was 23 hours.

[0335] After separating the precursor particles from the reaction solution, impurities were removed by washing, and the precursor for the cathode active material was prepared by drying in a drying oven at a temperature of 140°C for 12 hours and then sieving.

[0336]

[0337] Experimental Example 1: X-ray Diffraction Analysis and Characterization of Precursors for Anode Active Materials

[0338] X-ray diffraction analysis was performed on the precursors for cathode active materials prepared in Preparation Examples 1 to 6 above to evaluate the ratio of the (101) plane direction grain size (unit: nm) to the content of Ni in the total metal (unit: mol%), I(001) / I(100), and D 50 The SPAN value and pore area ratio (PAR) were measured using the following method. The results are shown in Table 1 below.

[0339]

[0340] (1) Ratio of (101) plane direction grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal

[0341] The precursor samples for the cathode active material prepared in Preparation Examples 1 to 6 above were placed in the recessed groove in the center of a general powder holder, and the surface of the sample was smoothed using a slide glass while simultaneously making the height equal to the edge of the holder. Then, X-ray diffraction analysis (XRD) was performed using an X-ray diffraction analyzer (Bruker, D8 Endeavor) under the following measurement conditions. The obtained XRD data was analyzed using the Fundamental Parameter Approach embedded in Bruker’s TOPAS program based on the Rietveld method to obtain the (101) plane direction grain size (unit: nm). Using the obtained data, the ratio of the (101) plane direction grain size (unit: nm) to the Ni content (unit: mol%) in the total metal was calculated.

[0342] - Measurement conditions: Light source: Cu Kα, λ=1.54Å, 2θ=10°~80°, Step size=0.02°, total scan time: 120min)

[0343]

[0344] (2) I(001) / I(100)

[0345] In the XRD data obtained when measuring the ratio of the (101) plane direction grain size (unit: nm) to the Ni content (unit: mol%) of the total metal, the I(001) / I(100) value can be measured by fitting using only the Lorenzian contribution as the FP (First Principle) among the peak types available in TOPAS, using all peaks of the measurement range. At this time, strain was not considered.

[0346]

[0347] (3) D 50

[0348] The precursors for the cathode active material prepared in Preparation Examples 1 to 6 above were collected and measured as a volume-based particle size distribution using a particle size distribution measuring device (Microtrac S3500, Microtrac). Specifically, 0.03g of the cathode active material precursor sample was dispersed in a dispersion medium, then introduced into the particle size distribution measuring device (Microtrac S3500, Microtrac) and irradiated with ultrasound of approximately 28kHz at an output of 60W to obtain a volume-cumulative particle size distribution graph, and the particle size at 50% of the volume-cumulative amount was measured by using the volume-cumulative particle size distribution graph.

[0349]

[0350] (101) Planar direction grain size / Ni content in total metal [nm / mol%] I(001) / I(100)D 50 [㎛] Preparation Example 11.80 3.4 12.3 Preparation Example 21.9 13.5 12.3 Preparation Example 32.88 4.5 12.4 Preparation Example 41.4 4.2 12.0 Preparation Example 52.13.7 12.0 Preparation Example 62.13.6 12.3

[0351] Examples and Comparative Examples

[0352] Example 1

[0353] The cathode active material precursor prepared in Preparation Example 1 above and LiOH were mixed such that the molar ratio of (Ni+Co+Mn) : Li was 1 : 1.05, and then calcined at 840°C for 10 hours to prepare the cathode active material. The prepared cathode active material is LiNi 0.7 Co 0.1 Mn 0.2 It has a composition of O2, with an average particle size D 50 It was confirmed that this is 12㎛ and has the form of a secondary particle.

[0354]

[0355] Example 2

[0356] A positive electrode active material was prepared using the same method as in Example 1, except that the precursor for the positive electrode active material prepared in Preparation Example 2 above was used. The prepared positive electrode active material is LiNi 0.7 Co 0.1 Mn 0.2 It was confirmed to have the composition of O2 and the form of secondary particles.

[0357]

[0358] Comparative Example 1

[0359] A positive electrode active material was prepared using the same method as in Example 1, except that the precursor for the positive electrode active material prepared in Preparation Example 3 above was used. The prepared positive electrode active material is LiNi 0.7 Co 0.1 Mn 0.2 It was confirmed to have the composition of O2 and the form of secondary particles.

[0360]

[0361] Comparative Example 2

[0362] A positive electrode active material was prepared using the same method as in Example 1, except that the precursor for the positive electrode active material prepared in Preparation Example 4 above was used. The prepared positive electrode active material is LiNi 0.7 Co 0.1 Mn 0.2 It was confirmed to have the composition of O2 and the form of secondary particles.

[0363]

[0364] Comparative Example 3

[0365] A positive electrode active material was prepared using the same method as in Example 1, except that the precursor for the positive electrode active material prepared in Preparation Example 5 above was used. The prepared positive electrode active material is LiNi 0.7 Co 0.1 Mn 0.2 It was confirmed to have the composition of O2 and the form of secondary particles.

[0366]

[0367] Comparative Example 4

[0368] A positive electrode active material was prepared using the same method as in Example 1, except that the precursor for the positive electrode active material prepared in Preparation Example 6 above was used. The prepared positive electrode active material is LiNi 0.7 Co 0.1 Mn 0.2 It was confirmed to have the composition of O2 and the form of secondary particles.

[0369]

[0370] Experimental Example 2: X-ray Diffraction Analysis and Characterization of Anode Active Material

[0371] X-ray diffraction analysis was performed on the cathode active materials prepared in Examples 1 and 2 and Comparative Examples 1 to 4 above to measure the ratio of average grain size (unit: nm) to the content of Ni (unit: mol%) among all metals excluding lithium (unit: mol%), I(003) / I(104). The results are shown in Table 2 below.

[0372]

[0373] (1) Ratio of average grain size (unit: nm) to the content of Ni (unit: mol%) among all metals excluding lithium

[0374] The cathode active material samples prepared in Examples 1 and 2 and Comparative Examples 1 to 4 were placed in the recessed groove in the center of a general powder holder. After leveling the surface of the sample using a slide glass and adjusting its height to be equal to the edge of the holder, X-ray diffraction (XRD) analysis was performed using an X-ray diffraction analyzer (Bruker, D8 Endeavor) under the following measurement conditions. The obtained XRD data was analyzed using the Fundamental Parameter Approach embedded in Bruker’s TOPAS program, which is based on the Rietveld method, to obtain the average grain size (unit: nm). Using the obtained data, the ratio of the average grain size (unit: nm) to the content of Ni (unit: mol%) among the total metals excluding lithium was calculated.

[0375] - Measurement conditions: Light source: Cu Kα, λ=1.54Å, 2θ=10°~80°, Step size=0.02°, total scan time: 120min)

[0376]

[0377] (2) I(003) / I(104)

[0378] In the XRD data obtained when measuring the ratio of the average grain size (unit: nm) to the content (unit: mol%) of Ni among the total metals excluding the lithium above, the I(003) / I(104) value can be measured by fitting using only the Lorenzian contribution as the FP (First Principle) among the peak types available in TOPAS, using all peaks of the measurement range. At this time, strain was not considered.

[0379]

[0380] (3) D 50

[0381] The cathode active materials prepared in Examples 1 and 2 and Comparative Examples 1 to 4 were collected and measured as a volume-based particle size distribution using a particle size distribution measuring device (Microtrac S3500, Microtrac). Specifically, 0.03g of the cathode active material sample was dispersed in a dispersion medium, then introduced into the particle size distribution measuring device (Microtrac S3500, Microtrac) and irradiated with ultrasound of approximately 28kHz at an output of 60W to obtain a volume-cumulative particle size distribution graph, and the particle size at 50% of the volume-cumulative amount was measured by using the volume-cumulative particle size distribution graph.

[0382]

[0383] Ratio of average grain size to Ni content among all metals excluding lithium [Unit: nm / mol%] I(003) / I(104)D 50[㎛] Example 1 2.9 7 1.1 85 6 11.50 Example 2 2.9 11.1 82 1 11.43 Comparative Example 16.4 3 1.2 20 6 11.52 Comparative Example 21.8 1.1 81 0 11.45 Comparative Example 3 3.0 3 1.1 80 4 11.8 Comparative Example 4 3.3 1.1 7 1 11.62

[0384] Experimental Example 3: Evaluation of Life Characteristics

[0385] An anode slurry was prepared by mixing the anode active material prepared in Examples 1-2 and Comparative Examples 1-4, carbon black as a conductive material, and PVdF as a binder with N-methylpyrrolidone in a weight ratio of 95.0:2.5:2.5. The anode slurry was applied to one side of an aluminum thin film, dried at 130°C, and then rolled to produce an anode.

[0386] A cathode was prepared by mixing artificial graphite, carbon black as a conductive material, and a styrene butadiene rubber (SBR)-carboxymethylcellulose (CMC) composite as a binder in a weight ratio of 95.5:1.0:3.5 to form a cathode slurry, which was then coated onto one side of a copper current collector, dried at 100°C, and rolled to produce an anode.

[0387] An electrode assembly was manufactured by interposing a separator between the anode and cathode manufactured above, and a lithium secondary battery was manufactured by placing the electrode assembly inside a battery case and injecting an electrolyte into the case. At this time, the electrolyte was prepared by dissolving 1.0 M lithium hexafluorophosphate (LiPF6) in an organic solvent mixed with ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in a volume ratio of 1:2.

[0388]

[0389] A lithium secondary battery to which the positive active material of Examples 1-2 and Comparative Examples 1-4 prepared above was applied was charged to 4.45V at 45℃ with a constant current of 0.5C, and then discharged to 2.5V with a constant current of 1.0C, with 50 cycles of charge and discharge being performed.

[0390]

[0391]

[0392] (1) Capacity retention rate

[0393] The capacity retention rate was calculated using the formula below, and the results are shown in Table 4 below.

[0394] - Capacity retention rate (%) = {(Discharge capacity after 50 cycles / Discharge capacity after 1 cycle)} × 100

[0395]

[0396] (2) Resistance increase rate

[0397] After one cycle of charging and discharging, the discharge capacity after one cycle was measured using an electrochemical charge / discharger, and the SOC was adjusted to 0%. Then, a pulse of 0.1C was applied for 60 seconds, and the initial resistance was calculated through the difference between the voltage before and after the pulse application.

[0398] After 50 cycles of charging and discharging, the resistance after 50 cycles was calculated using the same method as above, the resistance increase rate was calculated using the formula below, and the results are shown in Table 3 below.

[0399] Resistance increase rate (%) = (Resistance after 50 cycles - Initial resistance) / Initial resistance Υ 100

[0400] Capacitance Retention Rate [%] Resistance Increase Rate [%] Example 1 95.263.5 Example 2 94.578.1 Comparative Example 189.1115.2 Comparative Example 289.2118.1 Comparative Example 388.5101.2 Comparative Example 492.4120.4

[0401] Referring to Table 3 above, it can be confirmed that the lithium secondary battery using the positive active material of Examples 1 and 2, prepared using the positive active material precursor prepared in Preparation Examples 1 and 2, has a higher capacity retention rate and a lower resistance increase rate than the lithium secondary battery using the positive active material of Comparative Examples 1 to 4, prepared using the positive active material precursor prepared in Preparation Examples 3 to 6. Referring to all of Tables 1 to 3 above, it can be confirmed that the positive active material precursor used to prepare the positive active material of Examples 1 and 2, unlike the positive active material precursor used to prepare the positive active material of Comparative Examples 1 to 4, has a ratio of the (101) plane direction grain size relative to the Ni content in the total metal within the range of 1.5 nm / mol% to 2.0 nm / mol%. In addition, it can be confirmed that, unlike the cathode active materials of Comparative Examples 1 to 4, the ratio of the average grain size to the Ni content among the total metals excluding lithium falls within the range of 1.9 nm / mol% to 3.0 nm / mol% for the cathode active materials of Examples 1 and 2. From the above description, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. In this regard, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention should be interpreted as including all modifications or variations derived from the meaning and scope of the claims set forth below and their equivalent concepts, rather than from the above detailed description.

Claims

1. A nickel-based hydroxide containing 60 mol% or more of nickel among the total metals, and A precursor for a positive electrode active material, wherein the ratio of the (101) plane direction grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal is 1.5 nm / mol% to 2.0 nm / mol%.

2. In Paragraph 1, The above nickel-based hydroxide is a precursor for an anode active material represented by the following chemical formula 1. [Chemical Formula 1] Ni x0 Co y0 M 1 z0 M 2 w0 (OH)2 In the above chemical formula 1, 0.76≤x0<1.0, 0 <y0≤0.3, 0<z0≤0.3, 0≤w0≤0.1이고, M 1 is Mn, Al, or a combination thereof, and M 2 It is one or more doping elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, Sr, Ga, Sc, Ca, Nb, Mg, B, and Mo.

3. In Paragraph 1, Average particle size D 50 A precursor for a positive electrode active material having a thickness of 10.0㎛ to 15.0㎛.

4. In Paragraph 1, A precursor for an anode active material, wherein the nickel content among the total metals is 70 mol% to 80 mol%.

5. In Paragraph 1, A precursor for a positive electrode active material, wherein the crystal grain size in the (101) plane direction is 100 nm to 200 nm.

6. In Paragraph 1, A precursor for a positive electrode active material having an I(001) / I(100) value of 3.0 to 4.0 as measured by XRD.

7. A lithium nickel-based oxide comprising 60 mol% or more of nickel among all metals excluding lithium, and A positive electrode active material having a ratio of average grain size (unit: nm) to the content of Ni (unit: mol%) among all metals excluding lithium to 1.9 nm / mol% to 3.0 nm / mol%.

8. In Paragraph 7, The above positive active material is a positive active material comprising secondary particles.

9. In Paragraph 7, Average particle size D 50 A positive electrode active material having a thickness of 10.0㎛ or more and 15.0㎛ or less.

10. In Paragraph 7, A positive active material having an average grain size of 500 nm to 800 nm.

11. In Paragraph 7, A positive active material having an I(003) / I(104) value of 1.0 to 2.0 as measured by XRD.

12. A positive electrode comprising a positive electrode active material according to paragraph 7.

13. A lithium secondary battery comprising: a positive electrode according to claim 12; a negative electrode disposed opposite to the positive electrode; and an electrolyte.

14. A step of manufacturing an anode active material by mixing and calcining a lithium raw material and a precursor for an anode active material comprising a nickel-based hydroxide containing 60 mol% or more of nickel among the total metals; and A method for manufacturing a positive electrode active material, wherein the ratio of the (101) plane grain size (unit: nm) to the content of Ni (unit: mol%) in the total metal is 1.5 nm / mol% to 2.0 nm / mol%.

15. In Paragraph 14, A method for manufacturing an anode active material, wherein the above calcination is performed at a temperature of 600°C to 900°C.

16. In Paragraph 14, The above precursor for the positive electrode active material is, (1) A nucleation step of obtaining a reaction solution by co-precipitating an aqueous transition metal solution, an ammonium cation complex forming agent, and a basic compound to form a precursor nucleus for a positive electrode active material; and (2) A particle growth step in which a precursor particle for a positive active material is grown by co-precipitating a reaction solution in which a precursor particle for a positive active material is formed while supplying a transition metal aqueous solution, an ammonium cation complex forming agent, and a basic compound to the reaction solution in which the precursor particle for the positive active material is formed; the method of manufacturing a positive active material is manufactured through the particle growth step.

17. In Paragraph 16, A method for manufacturing a positive electrode active material, wherein the above step (1) is performed in a first reactor, and the above step (2) is performed after moving the reaction solution in which the precursor nucleus for the positive electrode active material is formed from the first reactor to a second reactor.

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