Positive electrode active material precursor for lithium secondary battery, positive electrode active material, and lithium secondary battery including the same

Abstract

The present embodiment relates to a positive electrode active material precursor for a lithium secondary battery, a positive electrode active material prepared using the same, and a lithium secondary battery including the same. The positive electrode active material precursor for a lithium secondary battery according to one embodiment includes a metal hydroxide, and has a BET of 25m 2 / g or more.

Description

[Technical Field]

[0001] The present embodiment relates to a positive electrode active material precursor for a lithium secondary battery, a positive electrode active material, and a lithium secondary battery including the same. [Background technology]

[0002] Recently, as environmental issues have become more serious, electric vehicles have been attracting attention as one solution to overcome these issues. Due to the explosive demand for electric vehicles and the demand for increased driving range, the development of secondary batteries with high capacity and high energy density to meet these needs has been actively pursued worldwide.

[0003] To meet these requirements, NCM cathode materials with a high Ni content are used, but to improve the density of the electrode plate, active research is being conducted on secondary batteries that use bimodal cathode active materials in which large and small particles are mixed at a certain ratio.

[0004] However, large-grain cathode materials, which are composed of secondary particles formed by agglomeration of primary particles, have a large specific surface area and therefore a large area in contact with the electrolyte, resulting in a large amount of gas generation, which shortens the battery life.Furthermore, small-grain cathode materials composed of secondary particles have a problem in that the small particles break down into primary particles during the rolling process due to their weak strength, which also shortens the battery life.

[0005] To solve this problem, a method has been proposed in which the size of the primary particles is increased to prepare a positive electrode active material in the form of single particles.

[0006] However, the single particles currently developed have problems in that they have poor performance in all aspects of electrochemical properties such as lifespan, resistance increase rate, and thermal stability. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present embodiment is to provide a positive electrode active material having excellent life characteristics and reduced resistance increase rate and gas generation, a method for producing the same, and a lithium secondary battery including the same. [Means for solving the problem]

[0008] The positive electrode active material precursor for a lithium secondary battery according to one embodiment includes a metal hydroxide and has a BET value of 25m 2 / g or more, more specifically 28-50m 2 / g range.

[0009] The precursor may have an average particle size (D50) in the range of 2 to 6 μm.

[0010] The metal hydroxides can include nickel, cobalt, and manganese.

[0011] Here, the content of the nickel may be 0.8 moles or more based on 1 mole of the total of the nickel, cobalt, and manganese.

[0012] A positive electrode active material for a lithium secondary battery according to another embodiment includes a metal oxide composed of single particles, and may have a packing density of 3.1 g / cc or more, more specifically, in the range of 3.15 to 3.5 g / cc.

[0013] The metal oxides may include nickel, cobalt, and manganese.

[0014] The content of the nickel may be 0.8 moles or more based on 1 mole of the total of the nickel, cobalt, and manganese.

[0015] The positive electrode active material may have an average particle size (D50) in the range of 5 to 15 μm.

[0016] A positive electrode for a lithium secondary battery according to yet another embodiment may include a current collector; and a positive electrode active material layer located on at least one surface of the current collector and including the positive electrode active material.

[0017] The positive electrode may have a plate density in the range of 3.5 to 4.0 g / cc.

[0018] A lithium secondary battery according to still another embodiment may include the positive electrode. [Effects of the Invention]

[0019] According to one embodiment, a high-nickel, medium-sized single particle positive electrode active material containing 80 mol % or more nickel can be produced, which can significantly improve the lifespan, initial resistance, resistance increase rate, and thermal stability, and can also significantly reduce the amount of gas generated during operation.

[0020] At the same time, it is possible to achieve a packing density equal to or higher than that of a multi-particle positive electrode active material, thereby increasing the energy density per volume of a lithium secondary battery.

[0021] Therefore, the volume of the lithium secondary battery can be reduced and the stability can be improved. [Brief explanation of the drawings]

[0022] [Figure 1] 1 shows the results of SEM analysis of the positive electrode active material precursor produced in Example 2, measured at 10,000 magnifications. [Figure 2] 1 shows the results of SEM analysis at 25,000 magnifications of a cross section of the positive electrode active material precursor produced in Example 2 after milling treatment with an FIB (Focused Ion Beam, SEIKO3050SE). [Figure 3] 1 shows the results of SEM analysis of the positive electrode active material precursor produced in Comparative Example 3, measured at 3,000 magnifications. [Figure 4]1 shows the results of SEM analysis at 5,000 magnifications of a cross section of the positive electrode active material precursor produced in Comparative Example 3 after milling treatment with a FIB (Focused Ion Beam, SEIKO3050SE). [Figure 5] 1 shows the results of SEM analysis of the positive electrode active material of Example 2 at 1,000 magnifications. [Figure 6] 1 shows the results of SEM analysis of the positive electrode active material of Example 2 at a magnification of 10,000. [Figure 7] 1 shows the results of SEM analysis of the positive electrode active material of Comparative Example 3 at a magnification of 1,000. [Figure 8] 1 shows the results of SEM analysis of the positive electrode active material of Comparative Example 3 at a magnification of 10,000. [Figure 9] 1 shows the results of SEM analysis of the positive electrode active material of Comparative Example 4 at a magnification of 1,000. [Figure 10] 1 shows the results of SEM analysis of the positive electrode active material of Comparative Example 4 at a magnification of 10,000. [Figure 11] 1 is a diagram for explaining a packing density measurement method. DETAILED DESCRIPTION OF THE INVENTION

[0023] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited to these. These terms are used to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Therefore, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0024] The terminology used herein is merely for the purpose of referring to particular embodiments and is not intended to limit the present invention. As used herein, the singular form includes the plural form unless the context clearly dictates otherwise. As used in the specification, the meaning of "comprising" embodies certain properties, regions, integers, steps, operations, elements, and / or components, and does not exclude the presence or addition of other properties, regions, integers, steps, operations, elements, and / or components.

[0025] When a part is referred to as being "on" another part, it can mean that it is directly on top of the other part, or there can be other parts between them. In contrast, when a part is referred to as being "directly on" another part, there are no other parts between them.

[0026] Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are additionally interpreted as having a meaning consistent with the relevant technical literature and the presently disclosed content, and are not interpreted as having an ideal or very formal meaning unless defined.

[0027] The positive electrode active material precursor for a lithium secondary battery according to one embodiment includes a metal hydroxide and has a BET value of 25m 2 More specifically, the BET of the positive electrode active material precursor may be 28 to 50 m / g or more. 2 / g range.

[0028] The precursor may have an average particle size (D50) of 2 to 6 μm, more specifically, in the range of 3 to 5 μm.

[0029] As mentioned above, the currently developed single particles have the problem of reduced electrochemical performance. One of the reasons for this is that the average particle size (D50) of the currently developed single particles is small, about 1-5 μm, and the slurry produced for electrode formation maintains high viscosity.

[0030] In this embodiment, in order to solve the problems of reduced thermal stability and increased gas generation when a multi-particle positive electrode active material is used and the problem of increased slurry viscosity when a single-particle positive electrode active material is used, a medium-sized single-particle positive electrode active material having an average particle size (D50) of approximately 6 to 15 μm is proposed, which is larger than the average particle size (D50) of currently developed single particles.

[0031] Specifically, to produce such a medium-sized cathode active material, it is important to improve the internal porosity and crystallinity during the preparation of the cathode active material precursor. To produce such a porous precursor, for example, a high-rate co-precipitation process can be used. In this embodiment, when the BET and average particle size (D50) of the cathode active material precursor satisfy the above ranges, the average particle size (D50) of the cathode active material produced using this precursor can be increased.

[0032] Meanwhile, the metal hydroxide may include nickel, cobalt, and manganese.

[0033] In this case, the nickel content may be 0.8 moles or more based on 1 mole of the total of the nickel, cobalt, and manganese, or 0.8 moles or more based on 1 mole of the total of the nickel, cobalt, and manganese, more specifically, the nickel content may be in the range of 0.85 to 0.99, or 0.87 to 0.99.

[0034] When the nickel content in the metal hydroxide is 0.8 mol or more, as in this embodiment, a cathode active material with high output characteristics can be realized. That is, a cathode active material prepared using the cathode active material precursor of this embodiment having such a composition has a high energy density per volume, thereby improving the capacity of the battery to which it is applied, and is highly suitable for use in electric vehicles.

[0035] According to an embodiment, a positive electrode active material for a lithium secondary battery may include a metal oxide composed of single particles, and the packing density of the positive electrode active material may be 3.1 g / cc or more, more specifically, in the range of 3.15 to 3.5 g / cc.

[0036] In this specification, the packing density refers to a value measured by applying a pressure of 4.5 tons to a circular pellet having a diameter of 13 mm prepared using the positive electrode active material.

[0037] When the packing density of the positive electrode active material satisfies the above range, the plate density of the positive electrode manufactured using the positive electrode active material can be further increased, thereby improving the energy density of the lithium secondary battery. As a result, when the positive electrode of the present embodiment is applied to an electric vehicle, the driving range can be significantly increased, which is advantageous.

[0038] The positive electrode active material includes a metal oxide composed of single particles, and the metal oxide may include nickel, cobalt, and manganese.

[0039] The composition of the metal oxide is the same as that of the precursor metal hydroxide described above, and therefore a detailed description thereof will be omitted here.

[0040] If necessary, the metal oxide may further include a doping element. The doping element may be, for example, one or more selected from the group consisting of Zr, Al, B, P, La, Ta, Ti, W, Mo, Si, Ga, Zn, Nb, Ag, Sn, Bi, Au, Y, Ge, V, Cr, and Fe. One of the doping elements may be selected and applied in consideration of the electrochemical properties to be achieved in a battery using the positive electrode active material of this embodiment.

[0041] Next, the average particle size (D50) of the positive electrode active material may be in the range of 6 to 15 μm, more specifically, 6 to 11 μm. By producing a single-particle positive electrode active material having such a medium particle size, it is possible to dramatically reduce the amount of gas generation and realize a lithium secondary battery with excellent electrochemical properties such as life, initial resistance, and resistance increase rate. At the same time, it is possible to achieve excellent thermal stability of the battery and increase the energy density per volume, which are very advantageous effects.

[0042] The cathode active material of the embodiment described above may be prepared by preparing a cathode active material precursor composed of a metal hydroxide, uniformly mixing the precursor with a lithium source material, and then calcining the mixture.

[0043] The metal hydroxide can be prepared by a coprecipitation method, for example, by preparing a metal salt aqueous solution containing a nickel source material, a cobalt source material, a manganese source material, and water, and then supplying the metal salt aqueous solution to a coprecipitation reactor, followed by adding a complexing agent and a precipitant to prepare the metal hydroxide.

[0044] At this time, by controlling the flow rate of the metal sulfate solution while performing high-speed coprecipitation, a porous positive electrode active material precursor having the BET value described above can be produced.

[0045] In another embodiment, a positive electrode including a positive electrode active material layer including the positive electrode active material according to one embodiment of the present invention is provided.

[0046] The plate density of the positive electrode may be in the range of 3.5 to 4.0 g / cc. When the plate density is in this range, the energy density of the lithium secondary battery can be significantly improved. Therefore, when the positive electrode according to the present embodiment is applied to an electric vehicle, the driving distance can be significantly increased.

[0047] Next, in this embodiment, there is provided a lithium secondary battery including the positive electrode, a negative electrode including a negative electrode active material, and an electrolyte located between the positive electrode and the negative electrode.

[0048] The description of the positive electrode active material is the same as that of the embodiment of the present invention described above, and therefore will be omitted.

[0049] The positive electrode active material layer may include a binder and a conductive agent.

[0050] The binder serves to effectively adhere the positive electrode active material particles to each other and to the current collector.

[0051] The conductive agent is used to impart conductivity to the electrode, and any electron-conductive material that does not undergo chemical change in the battery that is constructed can be used.

[0052] The negative electrode includes a current collector and a negative electrode active material layer formed on the current collector, and the negative electrode active material layer includes a negative electrode active material.

[0053] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, a lithium metal alloy, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0054] The material capable of reversibly intercalating / deintercalating lithium ions may be a carbon material, and any carbon-based negative electrode active material commonly used in lithium ion secondary batteries may be used. Representative examples thereof include crystalline carbon, amorphous carbon, or a combination of these.

[0055] As the lithium metal alloy, an alloy of lithium and a metal selected from the group consisting of Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used.

[0056] Examples of substances capable of doping and undoping lithium include Si, SiO x (0 < x < 2), Si-Y alloys (where Y is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, transition metals, rare earth elements, and combinations thereof, but not Si), Sn, SnO2, Sn-Y (where Y is an element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, transition metals, rare earth elements, and combinations thereof, but not Sn), and the like.

[0057] Examples of the transition metal oxide include vanadium oxide, lithium vanadium oxide, and the like. The negative electrode active material layer further contains a binder and may selectively further contain a conductive agent.

[0058] The binder serves to make the negative electrode active material particles adhere well to each other and also make the negative electrode active material adhere well to the current collector.

[0059] The conductive agent is used to impart conductivity to the electrode, and in the battery being constructed, any electron conductive material that does not cause a chemical change can be used.

[0060] As the current collector, those selected from the group consisting of copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof can be used.

[0061] The negative electrode and the positive electrode are manufactured by mixing an active material, a conductive agent, and a binder in a solvent to produce an active material composition, and applying this composition to a current collector. Since such an electrode manufacturing method is well-known in the art, a detailed description thereof is omitted herein. As the solvent, N-methylpyrrolidone and the like can be used, but are not limited thereto.

[0062] The electrolyte includes a non-aqueous organic solvent and a lithium salt.

[0063] The non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can migrate.

[0064] The lithium salt is dissolved in an organic solvent and serves as a lithium ion supply source in the battery, enabling basic operation of a lithium secondary battery, and promoting the movement of lithium ions between the positive electrode and the negative electrode.

[0065] Depending on the type of lithium secondary battery, a separator may be present between the positive electrode and the negative electrode. Such a separator may be made of polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more of these materials. Of course, mixed multilayer films such as a polyethylene / polypropylene two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polypropylene / polyethylene / polypropylene three-layer separator may also be used.

[0066] Lithium secondary batteries can be classified into lithium ion batteries, lithium ion polymer batteries, and lithium polymer batteries depending on the type of separator and electrolyte used, and into cylindrical, prismatic, coin, pouch, and other types depending on the shape, and into bulk and thin film types depending on the size. The structures and manufacturing methods of these batteries are widely known in the art, so detailed explanations will be omitted. [Example]

[0067] The following detailed description of the present invention is provided by way of example only, and the present invention is not limited thereto, but is defined only by the scope of the claims that follow.

[0068] Comparative Example 1 (1) Preparation of positive electrode active material precursor The nickel source material was NiSO4·6H2O, the cobalt source material was CoSO4·7H2O, and the manganese source material was MnSO4·H2O. These raw materials were dissolved in distilled water to prepare aqueous solutions of metal salts.

[0069] After preparing the coprecipitation reactor, N2 was purged to prevent oxidation of metal ions during the coprecipitation reaction, and the reactor temperature was maintained at 50°C.

[0070] NH4(OH) was added as a chelating agent to the co-precipitation reactor, and NaOH was used to adjust the pH. The precipitate obtained by the co-precipitation process was filtered, washed with distilled water, and dried in an oven at 100°C for 24 hours to prepare a cathode active material precursor.

[0071] The pH range during the coprecipitation stage is 11.0 to 12.0.

[0072] The total coprecipitation time was 40 hours. x Co y Mn z A precursor having the composition (OH) was prepared (x=0.80, y=0.1, Z=0.1) at a flow rate of 10 L / hr for the metal sulfate solution.

[0073] In this way (Ni x Co y Mn z Precursors with the composition )(OH)2 were grown to an average particle size (D50) of 2-6 μm.

[0074] (2) Manufacturing of positive electrode active material The precursor prepared in (1) was uniformly mixed with LiOH·H2O (SAMCHUN CHEMICALS, battery grade) in a molar ratio of 1:1.07, and the mixture was then fired in a box-type firing furnace where oxygen was introduced at 40 mL / min.

[0075] Specifically, after primary firing at 480°C for 5 hours, secondary firing was carried out at 700 to 780°C for 12 hours, with a temperature rise rate of 2.5°C / min.

[0076] The composition of the positive electrode active material produced in this way is LiNi 0.80 Co 0.10 Mn 0.10 It was O2.

[0077] Embodiments 1 to 4 and Comparative Examples 2 to 8 A positive electrode active material precursor and a positive electrode active material were prepared in the same manner as in Comparative Example 1, except that the composition of nickel, cobalt, and manganese, the coprecipitation time during precursor preparation, the flow rate of the metal sulfate solution, and the secondary firing temperature and maintenance time during active material preparation were adjusted as shown in Table 1 below.

[0078] [Table 1]

[0079] Experimental Example 1: Measurement of electrochemical properties (1) Manufacturing of coin-shaped half cells A CR2032 coin cell was fabricated using the cathode active material prepared as described above, and then electrochemical evaluation was performed.

[0080] Specifically, the positive electrode active material, conductive agent (Denka Black), and polyvinylidene fluoride binder (product name: KF1100) were mixed in a weight ratio of 96.5:1.5:2, and this mixture was added to N-methyl-2-pyrrolidone solvent so that the solid content was approximately 30 wt % to prepare a positive electrode active material slurry.

[0081] The slurry was coated on an aluminum foil (thickness: 15 μm) as a positive electrode current collector using a doctor blade, dried, and then rolled to prepare a positive electrode. The loading amount of the positive electrode was about 16.8 mg / cm. 2 The rolling density is about 3.6 g / cm 3It was.

[0082] A 2032 coin-type half cell was fabricated using the cathode, lithium metal anode (300 μm thick, MTI), electrolyte, and polypropylene separator in a conventional manner. The electrolyte was prepared by dissolving 1M LiPF in a mixed solvent of ethylene carbonate, dimethyl carbonate, and ethyl methyl carbonate (EMC) (mixing ratio of EC:DMC:EMC = 3:4:3 vol%).

[0083] (2) Evaluation of charge / discharge characteristics The coin-type half cell manufactured in (1) above was aged at room temperature (25° C.) for 10 hours, and then a charge / discharge test was performed.

[0084] The capacity evaluation was performed with 200 mAh / g as the reference capacity, and the charge / discharge conditions were constant current (CC) / constant voltage (CV) 3.0 V to 4.3 V with a 1 / 20 C cutoff. The initial capacity was measured by 0.1 C charge / 0.1 C discharge, followed by 0.2 C charge / 0.2 C discharge.

[0085] (3) Evaluation of cycle life characteristics at room temperature and high temperature The room temperature cycle life characteristics were measured 30 times at room temperature (25°C), and the high temperature cycle life characteristics were measured at high temperature (45°C) under the conditions of 1.0C charge / 1.0C discharge.

[0086] (4) Measurement of initial resistance and resistance increase rate The room temperature initial resistance (direct current internal resistance: DC-IR (Direct current internal resistance)) was calculated by applying a discharge current at 100% charge of 4.25 V by subjecting the battery to a charge-discharge cycle at 25°C and measuring the voltage value 60 seconds later.

[0087] The high temperature resistance increase rate was measured by measuring the resistance after 30 cycles in the same manner as the initial resistance measurement method relative to the resistance initially measured at high temperature (45°C) (high temperature initial resistance), and the increase rate was converted into a percentage (%) and recorded.

[0088] (5) Measurement of average leakage current The average leakage current was measured by maintaining the coin cell at 4.7 V at a high temperature of 55° C. for 120 hours and recording the average value.

[0089] [Table 2]

[0090] Referring to Table 2, it can be seen that the positive electrode active materials prepared according to Embodiments 1 to 4 have excellent room temperature and high temperature lifespans, as well as significantly lower room temperature initial resistance values ​​and resistance increase rates, compared to Comparative Examples 1 to 8. It can also be seen that the average leakage current and thermal stability of Embodiments 1 to 4 are improved compared to Comparative Examples 1 to 8.

[0091] Experimental Example 2 - Particle Analysis 1 and 3 show the results of SEM analysis of the positive electrode active material precursors prepared in Example 2 and Comparative Example 3, respectively, measured at 10,000x magnification in FIG. 1 and 3,000x magnification in FIG. 3.

[0092] 2 and 4 show the results of SEM analysis of cross sections of the positive electrode active material precursors produced in Example 2 and Comparative Example 3, respectively, after milling with a FIB (Focused Ion Beam, SEIKO3050SE). FIG. 2 shows the results at 25,000 magnifications, and FIG. 4 shows the results at 5,000 magnifications.

[0093] 1 to 4, it can be seen with the naked eye that the precursor of Example 2 contains more pores than the precursor prepared in Comparative Example 3.

[0094] FIG. 5 shows the results of SEM analysis of the positive electrode active material of Example 2 at a magnification of 1,000 times, and FIG. 6 shows the results of SEM analysis of the positive electrode active material of Example 2 at a magnification of 10,000 times.

[0095] FIG. 7 shows the results of SEM analysis of the positive electrode active material of Comparative Example 3 at a magnification of 1,000 times, and FIG. 8 shows the results of SEM analysis of the positive electrode active material of Comparative Example 3 at a magnification of 10,000 times.

[0096] FIG. 9 shows the results of SEM analysis of the positive electrode active material of Comparative Example 4 at a magnification of 1,000 times, and FIG. 10 shows the results of SEM analysis of the positive electrode active material of Comparative Example 4 at a magnification of 10,000 times.

[0097] 5 to 10, it can be seen that the crystal grain size of the positive electrode active material of the Examples is larger than that of the positive electrode active material prepared according to the Comparative Examples. Specifically, it is expected that the particle size of the positive electrode active material of Example 2 is larger than that of the positive electrode active material prepared according to Comparative Example 4, thereby increasing the packing density. Furthermore, compared to the positive electrode active material prepared according to Comparative Example 3, the positive electrode active material prepared according to Example 2 does not have as many voids, which is thought to suppress side reactions with the electrolyte.

[0098] As a result, as can be seen from Table 2, the positive electrode active materials of the examples were found to have improved room temperature initial resistance and high temperature resistance increase rate, as well as improved life characteristics, compared to the comparative examples.

[0099] Experimental Example 3 - Measurement of Packing Density The packing density was measured by forming circular pellets with a diameter of 13 mm using the positive electrode active materials prepared in the examples and comparative examples, and applying a pressure of 4.5 tons.

[0100] Specifically, the produced pellets were placed in a packing density measurement device, and pressure was applied as shown in Figure 11, and the height was measured to determine the packing density. The results are shown in Table 3 below.

[0101] Experimental Example 4: Measurement of gas generation rate The amount of gas generated was measured by the following method.

[0102] First, a CR2032 coin cell was prepared and charged / discharged at a constant current of 0.1C, followed by a full charge at 0.2C. The coin cell was then disassembled to extract the positive electrode, which was then washed with EMC electrolyte. The cleaned positive electrode was then placed in a pouch for measuring gas generation, and the electrolyte was then poured into it. The pouch was then stored in a 70°C oven for 4 hours, after which the amount of gas generated was measured using a hydrometer. The results are shown in Table 3 below.

[0103] Experimental Example 5 - Measurement of the average particle size of the active material and the BET of the precursor The average particle size (D50) of the positive electrode active materials prepared in the examples and comparative examples was measured using a particle size analyzer.

[0104] The specific surface area of ​​the positive electrode active material precursors prepared in the examples and comparative examples was measured using a BET measurement device (Micromeritics TriStar II 3020). The results are shown in Table 3 below.

[0105] [Table 3]

[0106] Referring to Table 3, it can be seen that the BET values ​​of the cathode active material precursors prepared in Examples 1 to 4 are significantly higher than those of Comparative Examples 1 to 8. In addition, it can be seen that the packing density values ​​of the cathode active materials of Examples 1 to 4 are superior to those of Comparative Examples 2, 4, 6, and 8, which are single particles, as well as those of Comparative Examples 1, 3, 5, and 7, which are multiparticles.

[0107] It can be seen that the amount of gas generated in Examples 1 to 4 was significantly reduced compared to multiparticulates and small diameter monoparticulates of the same composition.

[0108] Referring to the results of measuring the average particle size (D50), it can be seen that the positive electrode active materials having a single particle structure of Examples 1 to 4 have an average particle size (D50) value of about medium particle size.

[0109] The present invention is not limited to the above-described embodiments, and can be manufactured in various different forms, and a person skilled in the art to which the present invention pertains should understand that the present invention can be embodied in other specific forms without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and are not limiting.

Claims

1. Contains a metal hydroxide, BET is 25m ２ / g or more.

2. The BET of the positive electrode active material precursor is 28 to 50 m ２ The positive electrode active material precursor for a lithium secondary battery according to claim 1 , wherein the Mo content is in the range of 1 / g.

3. 2. The positive electrode active material precursor for a lithium secondary battery according to claim 1, wherein the average particle size (D50) of the precursor is in the range of 2 to 6 μm.

4. The metal hydroxide is 2. The positive electrode active material precursor for a lithium secondary battery according to claim 1, comprising nickel, cobalt, and manganese.

5. 5. The positive electrode active material precursor for a lithium secondary battery according to claim 4, wherein the content of the nickel is 0.8 moles or more based on 1 mole of the total of the nickel, cobalt, and manganese.

6. It contains a metal oxide composed of single particles, A positive electrode active material for a lithium secondary battery, having a packing density of 3.1 g / cc or more.

7. 7. The positive electrode active material for a lithium secondary battery according to claim 6, wherein the packing density is in the range of 3.15 to 3.5 g / cc.

8. The metal oxide is The positive electrode active material for a lithium secondary battery according to claim 6 , comprising nickel, cobalt, and manganese.

9. 9. The positive electrode active material for a lithium secondary battery according to claim 8, wherein the content of the nickel is 0.8 moles or more based on 1 mole of the total of the nickel, cobalt, and manganese.

10. 7. The positive electrode active material for a lithium secondary battery according to claim 6, wherein the average particle size (D50) of the positive electrode active material is in the range of 5 to 15 μm.

11. a current collector; and a positive electrode active material layer located on at least one surface of the current collector, the positive electrode active material layer comprising the positive electrode active material according to any one of claims 6 to 10; A positive electrode for a lithium secondary battery comprising:

12. 12. The positive electrode for a lithium secondary battery according to claim 11, wherein the positive electrode has a plate density in the range of 3.5 to 4.0 g / cc.

13. A lithium secondary battery comprising the positive electrode according to claim 12.

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