WO2018008952A1 - Method for manufacturing positive electrode active material for secondary battery and positive electrode active material for secondary battery, manufactured according to same - Google Patents

Method for manufacturing positive electrode active material for secondary battery and positive electrode active material for secondary battery, manufactured according to same Download PDF

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Publication number
WO2018008952A1
WO2018008952A1 PCT/KR2017/007114 KR2017007114W WO2018008952A1 WO 2018008952 A1 WO2018008952 A1 WO 2018008952A1 KR 2017007114 W KR2017007114 W KR 2017007114W WO 2018008952 A1 WO2018008952 A1 WO 2018008952A1
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active material
positive electrode
electrode active
precursor
secondary battery
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PCT/KR2017/007114
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French (fr)
Korean (ko)
Inventor
이혁
조승범
손산수
주진욱
최상순
김종필
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주식회사 엘지화학
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Priority claimed from KR1020170084337A external-priority patent/KR102026918B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to CN201780010065.6A priority Critical patent/CN108602689B/en
Priority to JP2018558102A priority patent/JP6968428B2/en
Priority to EP17824508.0A priority patent/EP3388394B1/en
Priority to US16/069,710 priority patent/US10637056B2/en
Publication of WO2018008952A1 publication Critical patent/WO2018008952A1/en

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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a method for producing a positive electrode active material and a positive electrode active material produced according to the present invention can be doped to uniformly doped without fear of damage on the surface of the active material and exhibit excellent structural stability.
  • Lithium secondary batteries have been widely used as power sources for portable devices since they emerged in 1991 as small, light and large capacity batteries. Recently, with the rapid development of electronics, telecommunications, and computer industry, camcorders, mobile phones, notebook PCs, etc. have emerged, and they are developing remarkably. Doing.
  • Lithium secondary batteries have a problem in that their lifespan drops rapidly as they are repeatedly charged and discharged. In particular, this problem is more serious under high temperature or high voltage. This is due to a phenomenon in which the electrolyte is decomposed or the active material is deteriorated due to moisture or other effects in the battery, and the internal resistance of the battery is increased.
  • LiCoO 2 having a layered structure. LiCoO 2 is most commonly used due to its excellent lifespan characteristics and charge and discharge efficiency. However, LiCoO 2 has a low structural stability and thus is not applicable to high capacity technology of batteries.
  • LiNiO 2 LiMnO 2 , LiMn 2 O 4 , LiFePO 4 or Li (Ni x CoyMnz) O 2
  • LiNiO 2 has the advantage of exhibiting battery characteristics of high discharge capacity, but the synthesis is difficult by a simple solid phase reaction, there is a problem of low thermal stability and low cycle characteristics.
  • lithium manganese oxides such as LiMnO 2 or LiMn 2 O 4 have advantages in that they are excellent in thermal safety and inexpensive, but have a small capacity and low temperature characteristics.
  • LiMn 2 O 4 but a part merchandising products to low cost, since the Mn + 3 structure modification (Jahn-Teller distortion) due to the not good life property.
  • LiFePO 4 has a low price and excellent safety and is currently being studied for a hybrid electric vehicle (HEV), but due to low conductivity it is difficult to apply to other fields.
  • Li (NixCoyMnz) O 2 is the most recently attracting attention as an alternative cathode active material for LiCoO 2 .
  • X, y, and z are atomic fractions of independent oxide composition elements, respectively, where 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 1, and 0 ⁇ x + y + z ⁇ 1.
  • This material is cheaper than LiCoO 2 and has advantages in that it can be used for high capacity and high voltage, but has a disadvantage in that the rate capability and the service life at high temperature are poor.
  • the positive electrode active material may be doped with Al, Ti, Sn, Ag, or Zn inside the positive electrode active material, or by dry or wet coating a conductive metal on the surface of the positive electrode active material.
  • the structural stability of the positive electrode active material is improved, but there is a problem that the capacity is lowered.
  • the uniform distribution of the doped material in the positive electrode active material is difficult, there is a problem of deterioration of the active material properties due to the non-uniform distribution of the doped material.
  • the first technical problem to be solved by the present invention is to improve the structural stability by uniformly doping with a doping element without fear of damage on the surface of the active material and deterioration of characteristics by using acoustic resonance, thereby improving capacity It is to provide a method for producing a positive electrode active material that can improve battery characteristics such as minimization and improved cycle characteristics.
  • the second technical problem to be solved by the present invention is to be prepared by the manufacturing method, having an improved structural stability, thereby providing a cathode active material that can improve the capacity, rate (rate) and cycle characteristics of the battery will be.
  • the third technical problem to be solved by the present invention is to provide a positive electrode and a lithium secondary battery including the positive electrode active material.
  • preparing a precursor doped with the doping element by mixing the metal precursor for the positive electrode active material and the raw material including the doping element using an acoustic resonance; And mixing the doped precursor with a lithium raw material, followed by heat treatment, wherein the raw material including the metal precursor and the doping element for the positive electrode active material has an average particle size ratio of 2000 to 5: 1. It provides a method of manufacturing.
  • a cathode active material for a secondary battery comprising the lithium composite metal oxide of Formula 2 prepared by the manufacturing method, doped with a metal element:
  • M comprises any one or two or more elements selected from the group consisting of Mn and Al,
  • M ' is any one selected from the group consisting of Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, and Cr or Contains two or more elements, and
  • a cathode and a lithium secondary battery including the cathode active material are provided.
  • the lithium composite metal oxide is used as a doping element without fear of damage on the surface of the active material and deterioration of properties.
  • the lithium composite metal oxide is used as a doping element without fear of damage on the surface of the active material and deterioration of properties.
  • Example 1 is a photograph of the doping precursor prepared in Example 1-1 using a scanning electron microscope (SEM).
  • Figure 2 is a photograph of the doping precursor prepared in Comparative Example 1-1 using the SEM.
  • Figure 3 is a photograph of the doping precursor prepared in Comparative Example 1-2 using the SEM.
  • FIG. 4 is a SEM photograph of the metal precursor (a)), the doped precursor (b), and the cathode active material (c) in the preparation of the cathode active material according to Example 1-1.
  • FIG. 5 is a SEM photograph of a metal precursor (a)), a doped precursor (b)) and a cathode active material (c) in the preparation of the cathode active material according to Comparative Example 1-1.
  • FIG. 6 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Example 1-2.
  • FIG. 6 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Example 1-2.
  • FIG. 7 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Example 1-3.
  • FIG. 7 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Example 1-3.
  • FIG. 8 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Comparative Example 1-3.
  • FIG. 8 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Comparative Example 1-3.
  • FIG. 9 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Comparative Example 1-4.
  • FIG. 9 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Comparative Example 1-4.
  • FIG. 10 is an SEM observation photograph of the result obtained after mixing the doped precursor and the lithium raw material during the preparation of the cathode active material according to Example 1-4.
  • FIG. 10 is an SEM observation photograph of the result obtained after mixing the doped precursor and the lithium raw material during the preparation of the cathode active material according to Example 1-4.
  • FIG. 11 is an SEM observation photograph of a result obtained after mixing a doped precursor and a lithium raw material during a process of preparing a cathode active material according to Comparative Example 1-1.
  • FIG. 12 is a graph illustrating discharge characteristics of the half-coin cell including the positive electrode active material prepared in Examples 1-4 and Comparative Examples 1-5.
  • Example 13 is a SEM photograph of the surface of the positive electrode active material prepared in Example 1-6.
  • the production of the conventionally doped cathode active material has been carried out by heat treatment after dry mixing or wet mixing of the cathode active material or its precursor and the dopant-containing raw material.
  • dry mixing the process is simple, but there is a problem that uniform dispersion or doping material is agglomerated easily, and dust is generated when fine powder is used.
  • wet mixing uniform dispersion and doping are possible as compared to dry, but there are disadvantages in that the process is complex.
  • both dry and wet methods had problems of dead zone generation due to agitation deviation during mixing and the possibility of mixing by a continuous process.
  • the metal precursor for the cathode active material and the doping element-containing raw material are mixed by using acoustic resonance, and the particles of the metal precursor and the doping element-containing raw material according to the acoustic resonance conditions are used.
  • the metal precursor can be uniformly doped with a doping element without fear of damage on the surface of the active material and deterioration of properties, and the dead zone due to the stirring variation can be minimized.
  • the structural stability of the positive electrode active material is significantly increased, thereby further improving the capacity, rate characteristics, and cycle characteristics of the battery.
  • Step 1 Preparing a precursor doped with the doping element by mixing the metal precursor for the positive electrode active material and the raw material including the doping element by using acoustic resonance (step 1); And
  • the raw material including the metal precursor and the doping element for the positive electrode active material is to have an average particle size ratio of 2000 to 5: 1.
  • step 1 is a step of preparing a doped precursor.
  • step 1 may be performed by mixing the metal precursor for the positive electrode active material and the raw material including the doping element by using acoustic resonance.
  • the mixing by acoustic resonance may be larger because the frequency of acoustic energy is several hundred times lower than that of ultrasonic mixing.
  • uniform mixing is possible because mixing occurs frequently in small scale mixing throughout the mixing system.
  • a doping element including a doping element such as yttria stabilized zirconia which is used for doping the metal precursor for the positive electrode active material, does not have uniform doping because of very low miscibility and reactivity to the precursor.
  • a doping element including a doping element such as yttria stabilized zirconia, which is used for doping the metal precursor for the positive electrode active material, does not have uniform doping because of very low miscibility and reactivity to the precursor.
  • by performing the mixing by acoustic resonance it is possible to increase the dispersibility of the raw material including the doping element, and to increase the reactivity to the precursor to uniformly doping the precursor surface.
  • Mixing by the acoustic resonance may be performed using a conventional acoustic resonance apparatus, and specifically, may be performed using an acoustic mixer.
  • the mixing process by acoustic resonance may have different mixing conditions depending on the particle size ratio of the metal precursor for the positive electrode active material and the raw material including the doping element, and furthermore, the damage and loss to the surface of the metal precursor and the active material. It may be desirable to optimize the particle size of the metal precursor and the doping element-containing raw material in order to obtain doping efficiency with a uniform and excellent efficiency while minimizing, and even more preferably to optimize each type together.
  • the average particle size ratio of the metal precursor for the cathode active material and the raw material including the doping element may be 2000 to 5: 1, more specifically 1000 to 5: 1 or 300 to 5: 1, and more specifically 7.5 To 5: 1.
  • the doping element-containing raw material may be uniformly dispersed with superior efficiency without damaging or losing the precursor particles.
  • the average particle diameter (D 50 ) of the doping element-containing raw material is 4 nm to 5 ⁇ m, or 10 nm to 5 ⁇ m, and more specifically 50 nm to 3 ⁇ m, and the average particle diameter of the metal precursor for the positive electrode active material ( Under the condition that D 50 ) is 10 ⁇ m to 20 ⁇ m, the metal precursor for the positive electrode active material and the raw material including the doping element may have an average particle size of 2000 to 5: 1, more specifically, 1000 to 5: 1, or 300 to 5: 1, and more specifically 7.5 to 5: 1.
  • mixing by acoustic resonance with respect to the metal precursor for the positive electrode active material and the doping element-containing raw material satisfying the particle size condition may be performed by applying acoustic energy of 50 g to 90 g, more specifically 50 g to 90 g of acoustic energy may be performed by applying 1 to 5 minutes.
  • the mixing mode of the doping material and the metal precursor may vary according to the structure of the metal precursor for the positive electrode active material.
  • the metal precursor for the positive electrode active material may be secondary particles in which a plurality of primary particles are aggregated, and the primary particles may have a plate-like shape.
  • the densities of the metal precursors on the secondary particles vary according to the plate thickness of the primary particles, and as a result, the doping aspect of the doping element for the metal precursor may vary. Therefore, more uniform and efficient doping is applied by optimizing the conditions at the time of the acoustic resonance according to the plate thickness of the primary particles.
  • the primary particles forming the metal precursor for the positive electrode active material have a plate-like shape, and the average thickness of the plate. May be 150 nm or less, and more specifically, 80 nm to 130 nm.
  • gap is formed between plate-shaped primary particles, and the metal precursor of secondary particle shape may have a large specific surface area.
  • the amount of the doping element to be doped may be small or the voids remain empty, and the doping by the doping element may be caused by the secondary particle metal. It can occur mainly at the precursor surface.
  • the mixing by the acoustic resonance is performed by applying a force of 50g to 90g for 1 to 4 minutes, the doping element is uniformly introduced into the pores between the primary particles on the plate can exhibit excellent doping efficiency, as a result As a result, the structural stability of the active material can be improved.
  • the 'plate shape' or 'plate shape' refers to an aggregate structure in which two surfaces corresponding or facing each other are flat, and the size in the horizontal direction is larger than the size in the vertical direction, Flakes, scales, and the like, which are similar in shape to a plate, may also be included.
  • grains is an average value of the plate
  • the primary particles forming the metal precursor for the positive electrode active material have a plate-like shape, and the average thickness of the plate
  • the metal precursor may be a secondary particle having a dense structure with less pore-shaped primary interparticle pores.
  • the doping element is more likely to be introduced into the pores between the primary particles of the doping element than the metal precursor including the thin plate-shaped primary particles.
  • the doping element It is mainly located on the surface, where local agglomeration of the doping element may occur locally on the secondary particulate surface.
  • a layer of the coating element on which the doping element is uniformly applied is formed on the precursor surface of the secondary particles.
  • the content of the doped lithium composite metal oxide on the surface of the active material increases, and as a result, the stability of the surface of the active material can be improved.
  • the doping element is specifically Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, Cr or the like, and may include any one or two or more of these.
  • the doping element may be an element corresponding to group 6 (VIB group) of the periodic table that can improve the structural stability of the active material by inhibiting particle growth during the firing process during the production of the active material particles. More specifically, the doping element may be any one or two or more elements selected from the group consisting of W, Mo and Cr, more specifically any one or two or more elements selected from the group consisting of W and Cr. Can be.
  • the doping element may be more specifically an element corresponding to Group 13 (Group IIIA) of the periodic table, and more specifically may be any one or two or more elements selected from the group consisting of B, Al, Ga and In. have.
  • the doping element may be any one or two or more elements selected from the group consisting of Group III (Group IIIB) and Group IV (Group IV) elements, more specifically, Ti, Sc, Y, Zr And La may be any one or two or more elements selected from the group consisting of.
  • the doping element may be an element corresponding to Group 5 (Group V) elements more specifically, and may be more specifically any one or two or more elements selected from the group consisting of V, Nb, and Ta. .
  • the doping element-containing raw material may be an oxide, hydroxide, or oxyhydroxide such as Al 2 O 3 including the doping element, and any one or a mixture of two or more thereof may be used.
  • the dopant-containing raw material may be a ceramic-based ion conductor that not only has excellent lithium ion conductivity in itself, but also may further improve the structure stability of the active material with a better doping effect when doping with a metal element derived therefrom.
  • the ceramic ion conductor may specifically include at least one of an ion conductive ceramic and a metal ceramic.
  • the ion conductive ceramics specifically include Y, Ca, Ni, such as yttria stabilized zirconia (YSZ ) , calcia stabilized zirconia (CSZ), scandia-stabilized zirconia (SSZ), and the like.
  • YSZ yttria stabilized zirconia
  • CSZ calcia stabilized zirconia
  • SSZ scandia-stabilized zirconia
  • ZrO 2 zirconia
  • GDC gadolinia doped ceria
  • SDC samarium doped ceria
  • YDC yttria-doped ceria
  • LSGM Lanthanum strontium gallate magnesite
  • LSM lanthanum strontium manganite
  • LSCF lanthanum strontium cobalt ferrite
  • the YSZ is a ceramic material made of zirconium oxide (zirconia) added with yttrium oxide (yttria) to be stable at room temperature.
  • the YSZ may be part of the yttria is added by being Zr 4 + ions to be substituted for the zirconia are Y 3+. This is replaced by three O 2 ions instead of four O 2 ions, resulting in oxygen vacancy.
  • the generated oxygen deficiency YSZ is O 2- ion have jeondoseongreul and the higher the temperature, the better the conductivity.
  • YSZ is Zr (1-x) Y x O 2 -x / 2 , where 0.01 ⁇ x ⁇ 0.30, and more specifically 0.08 ⁇ x ⁇ 0.10.
  • normal temperature means the temperature range in 23 +/- 5 degreeC unless it is specifically defined.
  • the YSZ is Zr (1-x) Y x O 2 -x / 2 (where, 0.01 ⁇ x ⁇ 0.30, and more specifically 0.08 ⁇ x ⁇ 0.10).
  • the metal ceramic is produced by mixing and sintering the ceramic and the metal powder, and has both the characteristics of a ceramic having high heat resistance and hardness, and a metal having plastic deformation or electrical conductivity.
  • the ceramic may be the ion conductive ceramic described above, and the metal may be nickel, molybdenum, cobalt, or the like. More specifically, the metal ceramic may be a cermet such as nickel-yttria stabilized zirconia cermet (Ni-YSZ cermet).
  • the average particle diameter (D 50 ) of the doping element containing the raw material may be 4nm to 5 ⁇ m.
  • the average particle diameter (D 50 ) of the doping element-containing raw material may be 10nm to 5 ⁇ m, even more specifically 50nm to 3 ⁇ m.
  • the average particle diameter (D 50 ) of the doping element containing the raw material may be defined as the particle size at 50% of the particle size distribution.
  • the average particle diameter (D 50 ) of the doping element-containing raw material may be measured by using a laser diffraction method, and specifically, introduced into a laser diffraction particle size measuring device (for example, Microtrac MT 3000) to about 28 after examining the kHz ultrasound of 60 W in output, it can be used to calculate the average particle diameter (D 50) of from 50% based on the particle size distribution of the measuring device.
  • a laser diffraction particle size measuring device for example, Microtrac MT 3000
  • the doping element-containing raw material is the content of the metal element derived from the doping element-containing raw material doped in the lithium composite metal oxide in the positive electrode active material to be produced finally Therefore, the amount of usage can be appropriately selected.
  • the doping element-containing raw material may be used in an amount of 500 ppm to 20,000 ppm, more specifically 1,000 ppm to 8,000 ppm with respect to the total content of the metal precursor for the positive electrode active material and the doping element-containing raw material. .
  • the metal precursor for the cathode active material is a material capable of forming a lithium composite metal oxide capable of reversible intercalation and deintercalation of lithium.
  • the metal-containing oxide, hydroxide, oxyhydroxide or phosphate for the positive electrode active material may be used, and any one or a mixture of two or more thereof may be used.
  • the metal for the positive electrode active material may specifically include one or two or more metal elements selected from the group consisting of nickel, cobalt manganese and aluminum.
  • the metal precursor for the positive electrode active material may be prepared by a conventional manufacturing method.
  • it when prepared by the coprecipitation method, it can be prepared by adding the ammonium cation-containing complex former and the basic compound to the aqueous solution of the metal-containing raw material for the positive electrode active material by coprecipitation reaction.
  • the metal-containing raw material for the positive electrode active material may be determined according to the composition of the lithium composite metal oxide constituting the target active material. Specifically, hydroxides, oxyhydroxides, nitrates, halides, carbonates, acetates, oxalates, citrates or sulfates containing metals constituting the lithium composite metal oxide may be used.
  • the cathode active material metal may be any one or two or more mixed metals selected from the group consisting of Fe, Ni, Co, Mn, Cr, Zr, Nb, Cu, V, Mo, Ti, Zn, Al, Ga and Mg. In more detail, it may be any one or two or more mixed metals selected from the group consisting of Ni, Co, Mn, and Al.
  • the cathode active material contains a lithium-nickel-cobalt-manganese compound as a lithium composite metal compound, as a precursor
  • nickel (Ni) is contained as a raw material for producing a metal-containing hydroxide for the cathode active material.
  • Raw materials, cobalt (Co) containing raw materials and manganese (Mn) containing raw materials may be used.
  • Each of the metal element-containing raw materials may be used without particular limitation as long as they are usually used in the production of the positive electrode active material.
  • the Co-containing raw material may be specifically Co (OH) 2 , CoO, CoOOH, Co (OCOCH 3 ) 2 ⁇ 4H 2 O, Co (NO 3 ) 2 ⁇ 6H 2 O or Co (SO 4 ) 2 7H 2 O and the like, any one or a mixture of two or more of the above compounds may be used.
  • the metal-containing raw material for the positive electrode active material is preferably used in an appropriate content ratio in consideration of the content of metals in the lithium composite metal oxide in the final positive electrode active material.
  • the metal-containing raw material for the positive electrode active material is water; Or it can be used as an aqueous solution by dissolving in the mixture of the organic solvent (specifically alcohol etc.) and water which can be mixed uniformly with water.
  • the organic solvent specifically alcohol etc.
  • ammonium cation-containing complex forming agent that can be used to prepare the metal-containing hydroxide for the positive electrode active material is specifically NH 4 OH, (NH 4 ) 2 SO 4 , NH 4 NO 3 , NH 4 Cl, CH 3 COONH 4 , or NH 4 CO 3 and the like, any one or a mixture of two or more thereof may be used.
  • the ammonium cation-containing complex forming agent may be used in the form of an aqueous solution, wherein the solvent is water; Alternatively, a mixture of water and an organic solvent (specifically alcohol or the like) that can be mixed with water uniformly can be used.
  • the basic compound usable for the preparation of the metal-containing hydroxide for the positive electrode active material may be a hydroxide of an alkali metal or alkaline earth metal such as NaOH, KOH, or Ca (OH) 2 , or a hydrate thereof, any one or two of them Mixtures of the above may be used.
  • the basic compound may also be used in the form of an aqueous solution, and as the solvent, a mixture of water or an organic solvent (specifically, alcohol, etc.) that can be mixed uniformly with water may be used.
  • the coprecipitation reaction for forming the particles of the metal-containing hydroxide for the positive electrode active material may be carried out under the condition that the pH of the aqueous solution of the metal-containing raw material is 8 to 14.
  • the pH value means a pH value at the temperature of the liquid 25 °C.
  • the coprecipitation reaction may be carried out in an inert atmosphere at a temperature of 30 °C to 60 °C.
  • the metal precursor for the positive electrode active material prepared by the manufacturing method as described above may be secondary particles in which a plurality of primary particles are aggregated.
  • the primary particles may have a plate shape. At this time, the plate thickness of the primary particles can be adjusted by controlling the reaction rate in the manufacturing process.
  • the metal precursor for the positive electrode active material may be secondary particles in which a plurality of primary particles having an average thickness of 150 nm or less, more specifically, 80 nm to 130 nm, are aggregated, or an average thickness of a plate is greater than 150 nm, Specifically, the secondary particles may be agglomerated secondary particles of 200 nm to 250 nm.
  • the average particle diameter (D 50 ) of the metal precursor for the positive electrode active material may be 4 ⁇ m to 30 ⁇ m, and more specifically 10 ⁇ m to 20 ⁇ m. When the average particle diameter of the precursor is in the above range, more efficient application is possible. In the present invention, the average particle diameter (D 50 ) of the metal precursor for the positive electrode active material may be defined as the particle size at 50% of the particle size distribution.
  • the average particle diameter (D 50 ) of the metal precursor for the positive electrode active material may be measured by using a laser diffraction method, and specifically, introduced into a laser diffraction particle size measuring apparatus (for example, Microtrac MT 3000) to about 28 after examining the kHz ultrasound of 60 W in output, it can be used to calculate the average particle diameter (D 50) of from 50% based on the particle size distribution of the measuring device.
  • a laser diffraction particle size measuring apparatus for example, Microtrac MT 3000
  • the doped metal element may be uniformly distributed in the precursor depending on the position preference of the metal element and the crystal structure of the precursor material, or may have a concentration gradient that increases or decreases the content distribution from the particle center of the precursor to the surface. Or on the surface side of the precursor.
  • step 2 is a step of preparing a cathode active material by mixing the doping precursor prepared in step 1 with a lithium raw material and heat treatment.
  • the lithium raw material examples include hydroxides, oxyhydroxides, nitrates, halides, carbonates, acetates, oxalates or citrates including lithium, and any one or a mixture of two or more thereof may be used.
  • the lithium raw material is Li 2 CO 3 , LiNO 3 , LiNO 2 , LiOH, LiOHH 2 O, LiH, LiF, LiCl, LiBr, LiI, CH 3 COOLi, Li 2 O, Li 2 SO 4 , CH 3 COOLi and Li 3 C 6 H 5 O 7 It may include any one or two or more compounds selected from the group consisting of.
  • the lithium raw material may be used in accordance with the lithium content in the final lithium composite metal oxide to be produced.
  • Mixing of the doped precursor and the lithium raw material may be performed by a conventional mixing method using a ball mill, a bead mill, a high pressure homogenizer, a high speed homogenizer, an ultrasonic dispersing apparatus, or the like. It may also be performed by acoustic resonance as shown.
  • the average particle size ratio of the doped precursor and the lithium raw material may be controlled to increase the mixing efficiency when mixing by the acoustic resonance. Specifically, the average particle size ratio of the doped precursor and the lithium raw material is 10: 1. To 3: 1.
  • the first heat treatment of the mixture of the doped precursor and the lithium raw material may be performed at a temperature of 700 ° C. to 950 ° C. If the temperature is less than 700 °C during the first heat treatment, there may be a decrease in discharge capacity per unit weight, cycle characteristics, and a decrease in operating voltage due to residual unreacted raw materials. There is a fear of lowering the discharge capacity per unit weight, lowering of cycle characteristics and lowering of operating voltage.
  • the primary heat treatment may be performed in the air or under an oxygen atmosphere, and may be performed for 5 hours to 30 hours.
  • the diffusion reaction between the particles of the mixture can be sufficiently made.
  • a cathode active material containing lithium composite metal oxide particles, wherein the lithium composite metal oxide present on the surface side of the particles is doped with a metal element derived from the doping element-containing raw material is prepared.
  • the method of manufacturing a cathode active material according to an embodiment of the present invention may further include a washing process for the resultant obtained after the first heat treatment in step 2.
  • the washing process may be performed using a conventional washing method such as mixing with water. More specifically, the washing process may be performed by mixing the resultant product with water by mixing by acoustic resonance.
  • the conventional water washing method has a water washing restriction due to the capillary phenomenon between the aggregated particles, and there is a problem in that the characteristics of the positive electrode active material are lowered when overwashing.
  • water dispersion can be easily performed, so that water washing can be performed with excellent efficiency without limitation of water washing, and the water washing time can be adjusted to prevent deterioration of the characteristics of the cathode active material. .
  • the acoustic resonance at the time of washing may be performed by applying 20g to 90g of acoustic energy for 10 seconds to 30 minutes.
  • the method of manufacturing a cathode active material according to an embodiment of the present invention may further include a surface treatment process for the resultant obtained after the heat treatment in the step 2 or after the washing process.
  • the surface treatment process may be carried out according to a conventional method, specifically, the resultant obtained after the heat treatment and the surface treatment agent may be performed by mixing using an acoustic resonance and then further heat treatment (hereinafter referred to as secondary heat treatment). .
  • the surface treatment agent is heat treated after mixing with Me raw material (Me is any one or two or more elements selected from the group consisting of Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn and Zr)
  • Me raw material Me is any one or two or more elements selected from the group consisting of Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn and Zr
  • Me-containing acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide or oxyhydroxide may be used as Me raw material.
  • Me is B
  • boric acid, lithium tetraborate, boron oxide, ammonium borate, and the like may be used, and any one or a mixture of two or more thereof may be used.
  • Me is tungsten, tungsten oxide (VI) etc. are mentioned.
  • the acoustic resonance treatment for forming the surface treatment layer may be performed by applying 30 g to 100 g of acoustic energy for 1 to 30 minutes.
  • the secondary heat treatment for forming the surface treatment layer may be performed at 300 °C to 900 °C.
  • the melting point of the Me raw material may be differently applied depending on the reaction temperature. If the secondary heat treatment temperature is less than 300 ° C., the surface treatment layer may not be sufficiently formed.
  • the atmosphere during the heat treatment is not particularly limited, and may be performed in a vacuum, inert or air atmosphere.
  • a surface treatment layer including the compound of formula 1 may be formed on the surface of the active material by the surface treatment process as described above:
  • Me is any one or two or more elements selected from the group consisting of Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn and Zr, 2 ⁇ m ⁇ 10, n is the oxidation number of Me)
  • the doping element is uniformly dispersed and doped as compared to the doping by the conventional dry mixing method or wet mixing method, thereby greatly improving the structural safety, as a result of battery application Dose reduction can be minimized. At the same time, the output characteristics, rate characteristics and cycle characteristics can be further improved.
  • a cathode active material prepared by the above-described manufacturing method is provided.
  • the cathode active material includes a lithium composite metal oxide doped with the doping element. More specifically, the lithium composite metal oxide doped with the doping element may be uniformly distributed in the precursor, or may have a concentration gradient that increases or decreases in content distribution from the particle center of the precursor to the surface, or May exist only on the surface side.
  • the 'surface side' of the lithium composite metal oxide particles means a region close to the surface except for the center of the particles, specifically, the distance from the surface of the lithium composite metal oxide particles to the center, that is, the lithium composite metal oxide Means a region corresponding to a distance of 0% or more and less than 100% from the particle surface, more specifically 0% to 50% from the particle surface, and more specifically 0% to 30% from the particle surface with respect to the semi-diameter of .
  • the lithium composite metal oxide doped by the metal element of the ceramic ion conductor may be a compound of Formula 2 below:
  • M is at least one metal element selected from the group consisting of Mn and Al,
  • M ' is a metal element derived from a dopant-containing raw material, specifically, Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, It may be any one selected from the group consisting of W, Mo, and Cr or a mixed element of two or more thereof, more specifically in the group consisting of Y, Zr, La, Sr, Ga, Sc, Gd, Sm and Ce It may be any one or two or more mixed elements selected, and more specifically at least one element selected from the group consisting of Y and Zr, provided that M and M 'may be different elements.
  • 0 ⁇ A ⁇ 1, 0 ⁇ a ⁇ 0.33, 0 ⁇ b ⁇ 0.5, 0 ⁇ c ⁇ 0.5, and 0 ⁇ s ⁇ 0.2, but b and c are not 0.5 at the same time. More specifically, 0 ⁇ a ⁇ 0.09 under conditions satisfying A, b, c, and s, and more specifically 0.9 ⁇ A ⁇ 1, a under conditions satisfying b, c, and s. It may be zero.
  • the effect of doping the raw material including the doping element on the lithium composite metal particles is not more than about 10% of the difference in life characteristic effect compared to the case of doping the metal element by a conventional doping method. You may not.
  • the effect of doping the raw material including the doping element on the lithium composite metal oxide particles is 30% longer than the case of doping the metal element by the conventional doping method. Up to 70%.
  • M ' may be distributed in a concentration gradient gradually decreasing from the particle surface to the center in the particles of the lithium composite metal oxide.
  • concentration of the doped metal is gradually changed according to the position of the particles of the positive electrode active material, so that there is no abrupt phase boundary region in the active material, so that the crystal structure is stabilized and thermal stability is increased.
  • the doping element is distributed at a high concentration on the surface side of the active material particles and includes a concentration gradient in which the concentration decreases toward the particle center, it is possible to prevent a decrease in capacity while exhibiting thermal stability.
  • the concentration of the doping element M ' indicates a concentration gradient, based on the total atomic weight of the doping element M' included in the positive electrode active material, 10% by volume from the center of the particle
  • the difference between the concentrations of M 'in the region within (hereinafter referred to simply as' Rc 10 region') and the region within 10% by volume (hereinafter referred to simply as' Rs 10 region ') is 10 to 90 atoms. %
  • the concentration difference of M ′′ may be from 10 atomic% to 90 atomic%.
  • the concentration gradient structure and the concentration of the doping element in the positive electrode active material particles are determined by the Electron Microbe (Electron Probe Micro Analyzer, EPMA), Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-). AES) or Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and more specifically, using EPMA to move from the center of the cathode active material to the surface. While measuring the atomic ratio of each metal (atomic ratio) can be measured.
  • the cathode active material according to an embodiment of the present invention may further include a surface treatment layer made of the lithium composite metal oxide of Chemical Formula 2 when using a metal precursor made of primary particles having a plate thickness of more than 150 nm.
  • the surface treatment layer may be formed in a thickness ratio of 0.001 to 0.1 with respect to the semi-diameter of the lithium composite metal oxide particles on the surface of the lithium composite metal oxide particles, more specifically, may be formed in a thickness range of 1nm to 1000nm. .
  • the cathode active material according to an embodiment of the present invention may be primary particles of a lithium composite metal oxide or secondary particles formed by assembling the primary particles.
  • the cathode active material is a primary particle of a lithium composite metal oxide
  • generation of surface impurities such as Li 2 CO 3 , LiOH, and the like caused by reaction with moisture or CO 2 in the air is reduced, thereby reducing battery capacity and gas generation.
  • excellent high temperature stability can be exhibited.
  • the cathode active material is secondary particles in which primary particles are assembled, output characteristics may be more excellent.
  • the primary average particle size (D 50) of the particles may be 10nm to 200nm.
  • the form of such active material particles may be appropriately determined according to the composition of the lithium composite metal oxide constituting the active material.
  • a positive electrode including the positive electrode active material prepared by the above-described manufacturing method.
  • the positive electrode may be manufactured by a conventional positive electrode manufacturing method known in the art, except for using the positive electrode active material described above.
  • a positive electrode is prepared by mixing and stirring a solvent, a binder, a conductive material, or a dispersant in a positive electrode active material, if necessary, and then coating (coating) and drying the positive electrode current collector to form a positive electrode active material layer. can do.
  • the positive electrode current collector is a metal having high conductivity, and may be any metal as long as it is a metal that the slurry of the positive electrode active material can easily adhere to.
  • Non-limiting examples of the positive electrode current collector include a foil made of aluminum, nickel, or a combination thereof.
  • the solvent for forming the positive electrode includes an organic solvent such as NMP (N-methyl pyrrolidone), DMF (dimethyl formamide), acetone, dimethyl acetamide or water, and these solvents are used alone or 2 It can mix and use species.
  • the amount of the solvent used is sufficient to dissolve and disperse the positive electrode active material, the binder, and the conductive material in consideration of the coating thickness of the slurry and the production yield.
  • the binder may be vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, poly Vinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), liquor
  • Various types of binder polymers can be used, such as fonned EPDM, styrene butadiene rubber (SBR), fluorine rubber, poly acrylic acid and polymers in which hydrogen thereof is replaced with Li, Na or Ca, or various copolymers. have.
  • the binder may be included in an amount of 1 to 30% by weight based on the total weight of the positive electrode active material layer.
  • the conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery.
  • Examples of the conductive material include graphite such as natural graphite and artificial graphite; Carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, farnes black, lamp black, thermal black, carbon nanotubes or carbon fibers; Metal powder or metal fibers such as copper, nickel, aluminum, and silver; Conductive whiskers such as fluorocarbon, zinc oxide or potassium titanate; Conductive metal oxides such as titanium oxide; Or conductive polymers such as polyphenylene derivatives, and any one or a mixture of two or more thereof may be used.
  • the conductive material may be included in an amount of 1 to 30 wt% based on the total weight of the cathode active material layer.
  • a lithium secondary battery including the cathode active material manufactured by the above-described manufacturing method.
  • the lithium secondary battery specifically includes a separator interposed between the positive electrode, the negative electrode, the positive electrode and the negative electrode.
  • a carbon material lithium metal, silicon, tin, or the like, in which lithium ions may be occluded and released, may be used.
  • a carbon material may be used, and as the carbon material, both low crystalline carbon and high crystalline carbon may be used.
  • Soft crystalline carbon and hard carbon are typical low crystalline carbon, and high crystalline carbon is natural graphite, Kish graphite, pyrolytic carbon, liquid crystal pitch carbon fiber.
  • High temperature calcined carbon such as (mesophase pitch based carbon fiber), meso-carbon microbeads, Mesophase pitches and petroleum or coal tar pitch derived cokes.
  • the negative electrode current collector is generally made of a thickness of 3 ⁇ m to 500 ⁇ m.
  • a negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery.
  • the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver, and the like, aluminum-cadmium alloy, and the like can be used.
  • fine concavities and convexities may be formed on the surface to enhance the bonding strength of the negative electrode active material, and may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.
  • the binder and the conductive material used for the negative electrode may be used as can be commonly used in the art as the positive electrode.
  • the negative electrode may prepare a negative electrode by mixing and stirring the negative electrode active material and the additives to prepare a negative electrode active material slurry, and then applying the same to a current collector and compressing the negative electrode.
  • porous polymer films conventionally used as separators for example, polyolefins such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer and ethylene / methacrylate copolymer, etc.
  • the porous polymer film made of the polymer may be used alone or by laminating them, or a conventional porous nonwoven fabric, for example, a non-woven fabric made of high melting point glass fiber, polyethylene terephthalate fiber, or the like may be used. It is not.
  • Examples of the electrolyte used in the present invention include an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel polymer electrolyte, a solid inorganic electrolyte, a molten inorganic electrolyte, and the like, which can be used in manufacturing a lithium secondary battery. no.
  • the lithium salt which can be included as an electrolyte used in the present invention can be used without limitation, those which are commonly used in a lithium secondary battery electrolyte, such as the lithium salt, the anion is F -, Cl -, Br -, I -, NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, CF 3 CF 2 SO 3 -, (CF 3 SO 2) 2 N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 - may be any one
  • the lithium secondary battery having the above configuration may be manufactured by manufacturing an electrode assembly through a separator between a positive electrode and a negative electrode, placing the electrode assembly inside a case, and then injecting an electrolyte solution into the case.
  • the lithium secondary battery including the cathode active material according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate, portable devices such as mobile phones, notebook computers, digital cameras, and hybrid electric vehicles It is useful in the field of electric vehicles.
  • a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided.
  • the battery module or the battery pack is a power tool (Power Tool); Electric vehicles including electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); Or it can be used as a power source for any one or more of the system for power storage.
  • Power Tool Electric vehicles including electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); Or it can be used as a power source for any one or more of the system for power storage.
  • YSZ yttria-stabilized zirconia
  • the acoustic energy of 60g was applied for 2 minutes using an acoustic mixer (LabRAM II) to obtain a precursor doped with ceramic elements (Y and Zr) derived from the raw material including the YSZ doping element.
  • LiOH was added at a molar ratio of 1.02 to the doped precursor and mixed for 10 minutes at 15000 rpm using a blending mixer, followed by heat treatment at 800 ° C. in an oxygen atmosphere to prepare a positive electrode active material of a lithium composite metal oxide doped with Y and Zr. It was.
  • LiOH was added to the mixed precursor at a molar ratio of 1.02, and the mixture was mixed at 15000 rpm for 10 minutes using a blending mixer, followed by secondary heat treatment at 800 ° C. in an oxygen atmosphere to prepare a cathode active material.
  • LiOH was added to the resultant reactant at a molar ratio of 1.02, and the mixture was mixed at 15000 rpm for 10 minutes using a blending mixer, and then calcined at 800 ° C. in an oxygen atmosphere to prepare a cathode active material.
  • Example 1-1 In preparing the cathode active materials according to Example 1-1 and Comparative Examples 1-1 and 1-2, the doped precursor was observed under a scanning electron microscope. The results are shown in FIGS. 1 to 3, respectively.
  • a positive electrode active material was prepared in the same manner as in Example 1, except that the particle size of the precursor particles and the doping element-containing raw material were variously changed as shown in Table 1 below.
  • Example 1-2 Example 1-3 Comparative Example 1-3 Comparative Example 1-4 Average Plate Thickness of Primary Particles in Metal Precursors (nm) 100 230 100 230 Metal precursor average particle diameter (D 50 ) ( ⁇ m) 15 15 15 15 15 Average particle size of raw material including doping element (D 50 ) ( ⁇ m) 2 3 3.5 4
  • the average plate thickness of the primary particles in the prepared metal precursor was observed and measured using a scanning electron microscope, and the average particle diameter of the metal precursor on the secondary particles and the average particle diameter of the raw material including the doping element were A metal precursor and a doping element-containing raw material were respectively introduced into a laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with an ultrasonic wave of about 28 kHz at an output of 60 W.
  • the average particle diameter (D 50 ) of was calculated.
  • Examples 1-2 and 1-3 where a metal precursor having a D 50 of 15 ⁇ m and a raw material including a doping element having a D 50 of 2 ⁇ m or 3 ⁇ m was mixed, the precursors were homogeneous by uniform mixing.
  • the doping element-containing raw material was partially aggregated and distributed on the precursor surface on the precursor surface, and the doping material was partially aggregated and present.
  • YSZ yttria-stabilized zirconia
  • LiOH was added to the doped precursor at a molar ratio of 1.02, and 80 g of acoustic energy was mixed for 2 minutes using an acoustic mixer (LabRAM II), followed by heat treatment at 800 ° C. in an oxygen atmosphere, and Y, Zr, and Al were doped.
  • a cathode active material of the lithium composite metal oxide was prepared.
  • YSZ yttria-stabilized zirconia
  • LiOH was added at a molar ratio of 1.02 to the doped precursor and mixed for 10 minutes at 15000 rpm using a blending mixer, followed by secondary heat treatment at 800 ° C. in an oxygen atmosphere to form a positive electrode of a lithium composite metal oxide doped with Y, Zr, and Al.
  • An active material was prepared.
  • Example 1-4 the doping precursor and the lithium raw material were uniform even though the acoustic mixing process time for the doped precursor and the lithium raw material was shorter than that of the blending mixing process in Comparative Example 1-1. After mixing, the lithium raw material was uniformly dispersed on the surface of the precursor particles. In addition, no damage to the doped precursor particle surface and bulk was observed. In addition to the manufacturing process of the doping precursor in the preparation of the doped cathode active material from this, it can be seen that it is possible to produce a cathode active material having better surface properties without surface damage by applying acoustic resonance when mixing with the lithium raw material after the doping.
  • the cathode active material prepared in Example 1-4, super P as a conductive material and PVDF as a binder were mixed at a polymerization ratio of 92.5: 2.5: 5 to prepare a composition for forming a cathode. After coating it on an aluminum foil, it was uniformly compressed using a roll press and vacuum dried for 12 hours at 130 ° C. in a vacuum oven to prepare a cathode for a lithium secondary battery. After the production of a half coin cell (half coin cell) of the 2032 standard using the positive electrode was evaluated the capacity characteristics. At this time, the half-coin cell was prepared using the cathode active material prepared in Comparative Example 1-5 for comparison.
  • the capacity characteristics of the lithium secondary battery is charged at 25 ° C. with a constant current (CC) of 0.2C until 4.25V, and then charged with a constant voltage (CV) of 4.25V until the charging current reaches 0.05mAh.
  • the first charge was performed. After standing for 20 minutes, the battery was discharged until it reached 2.5V with a constant current of 0.2C. Through this, the discharge capacity was evaluated and compared. The results are shown in Table 2 and FIG. 12.
  • the capacity characteristics of the battery are reduced, and additionally, particles which may act as impurities on the surface are generated due to the inhomogeneous doping or doping raw material remaining and agglomeration, thereby improving the battery characteristics. Can be reduced.
  • the battery containing the positive electrode active material of Example 1-4 showed a higher capacity characteristics than Comparative Example 1-5, from which the doping efficiency in the positive electrode active material prepared by the manufacturing method according to the present invention You can see that this is higher.
  • YSZ yttria-stabilized zirconia
  • LiOH was added to the doped precursor at a molar ratio of 1.03, and 80 g of acoustic energy was mixed for 2 minutes using an acoustic mixer (LabRAM II), followed by heat treatment at 780 ° C. in an oxygen atmosphere.
  • the resultant obtained after the heat treatment was dispersed in deionized water, and then washed with an acoustic mixer (LabRAM II) while applying 40g of acoustic energy for 5 minutes, filtered for 3 minutes or more, and then dried in a vacuum oven at 130 ° C. for 12 hours or more.
  • a cathode active material of a lithium composite metal oxide doped with Y, Zr, and Al was prepared.
  • Example 1-6 Of positive electrode active material Produce
  • LiOH was added to the mixed precursor at a molar ratio of 1.03, and 80 g of acoustic energy was applied for 2 minutes using an acoustic mixer (LabRAM II), followed by mixing, followed by heat treatment at 780 ° C. in an oxygen atmosphere.
  • the resultant after the heat treatment was dispersed in deionized water, washed with a mechanical stirrer (mechanical stirrer) for 5 minutes at 400rpm, filtered for 3 minutes, and then dried for 12 hours at 130 °C vacuum oven to prepare a cathode active material.
  • LiOH (% by weight) 100 ⁇ [(2 ⁇ EP-FP) ⁇ 0.1 ⁇ 0.001 ⁇ 23.94] / 5
  • Li 2 CO 3 (% by weight) 100 ⁇ [(FP-EP) ⁇ 0.1 ⁇ 0.001 ⁇ 73.89] / 5
  • Equations 1 and 2 EP is an evaluation point and FP is a fixed point.
  • the positive electrode active material of Example 1-5 using the acoustic mixer during the washing process showed a lower content of impurities and a pH value than those of Example 1-6.
  • a positive electrode active material of a lithium composite metal oxide doped with Al was prepared in the same manner as in Example 1-5, except that Al 2 O 3 was used instead of YSZ.
  • a positive electrode active material of a lithium composite metal oxide doped with ceramic elements (Sc and Zr) derived from a raw material including an SSZ doping element was prepared in the same manner as in Example 1-5 except that SSZ was used instead of YSZ. It was.
  • N-methyl-2 Positive electrode slurry was prepared by addition to pyrrolidone (NMP).
  • NMP pyrrolidone
  • the positive electrode slurry was applied to a thin film of aluminum (Al), which is a positive electrode current collector having a thickness of about 20 ⁇ m, dried to prepare a positive electrode, and then roll rolled to prepare a positive electrode.
  • LiPF 6 was added to a non-aqueous electrolyte solvent prepared by mixing ethylene carbonate and diethyl carbonate as a electrolyte in a volume ratio of 30:70 to prepare a 1 M LiPF 6 non-aqueous electrolyte.
  • a cell was prepared by injecting a lithium salt-containing electrolyte solution through a separator of porous polyethylene between the positive electrode and the negative electrode prepared above.
  • a lithium secondary battery was manufactured by the same method as in Example 2-1, except for using the cathode active materials prepared in Examples 1-2 to 1-8, respectively.
  • the positive electrode active material doped with a metal element containing a doping element using an acoustic resonance has improved structural stability, thereby minimizing capacity reduction in battery application. It was confirmed to exhibit excellent cycle characteristics.

Abstract

The present invention provides a method for manufacturing a positive electrode active material for a secondary battery, comprising the steps of: mixing a metal precursor for a positive electrode active material having an average particle diameter ratio of 2000 to 5:1 with a raw material including a doping element by using acoustic resonance to prepare a precursor having been doped by the doping element; and mixing the doped precursor with a lithium raw material and then heat-treating the same, so that the secondary battery is uniformly doped by various doping elements without a danger of damage to a surface of the active material and property deterioration thereof. Further, the present invention provides a positive electrode active material, which is manufactured by the method and thus has an improved structural stability, and can enhance a property of a battery, to which the method is applied, for example, can minimize reduction of the capacity of the battery and improve a cycle property thereof.

Description

이차전지용 양극활물질의 제조방법 및 이에 따라 제조된 이차전지용 양극활물질Method for manufacturing cathode active material for secondary battery and cathode active material for secondary battery manufactured accordingly
관련출원과의 상호인용Citation with Related Applications
본 출원은 2016년 7월 4일자 한국 특허 출원 제10-2016-0084359호 및 2017년 7월 3일자 한국 특허 출원 제10-2017-0084337호에 기초한 우선권의 이익을 주장하며, 해당 한국 특허 출원의 문헌에 개시된 모든 내용은 본 명세서의 일부로서 포함된다.This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0084359 dated July 4, 2016 and Korean Patent Application No. 10-2017-0084337 dated July 3, 2017. All content disclosed in the literature is included as part of this specification.
기술분야Technical Field
본 발명은 활물질 표면에서의 손상 및 특성 저하에 대한 우려 없이, 도핑원소가 균일하게 도핑되어 우수한 구조 안정성을 나타낼 수 있는 양극활물질의 제조방법 및 이에 따라 제조된 양극활물질에 관한 것이다.The present invention relates to a method for producing a positive electrode active material and a positive electrode active material produced according to the present invention can be doped to uniformly doped without fear of damage on the surface of the active material and exhibit excellent structural stability.
리튬 이차전지는 소형, 경량, 대용량 전지로서 1991년에 등장한 이래, 휴대기기의 전원으로서 널리 사용되었다. 최근 들어 전자, 통신, 컴퓨터 산업의 급속한 발전에 따라 캠코더, 휴대폰, 노트북 PC등이 출현하여 눈부신 발전을 거듭하고 있으며, 이들 휴대용 전자정보통신기기들을 구동할 동력원으로서 리튬 이차전지에 대한 수요가 나날이 증가하고 있다.Lithium secondary batteries have been widely used as power sources for portable devices since they emerged in 1991 as small, light and large capacity batteries. Recently, with the rapid development of electronics, telecommunications, and computer industry, camcorders, mobile phones, notebook PCs, etc. have emerged, and they are developing remarkably. Doing.
리튬 이차전지는 충방전을 거듭함에 따라서 수명이 급속하게 떨어지는 문제점이 있다. 특히, 고온 또는 고전압 하에서는 이러한 문제가 더욱 심각하다. 이러한 이유는 전지내부의 수분이나 기타 다른 영향으로 인해 전해질이 분해되거나 활물질이 열화되고, 또한 전지의 내부저항이 증가되어 생기는 현상 때문이다. Lithium secondary batteries have a problem in that their lifespan drops rapidly as they are repeatedly charged and discharged. In particular, this problem is more serious under high temperature or high voltage. This is due to a phenomenon in which the electrolyte is decomposed or the active material is deteriorated due to moisture or other effects in the battery, and the internal resistance of the battery is increased.
이에 따라 현재 활발하게 연구 개발되어 사용되고 있는 리튬 이차전지용 양극활물질은 층상구조의 LiCoO2이다. LiCoO2는 수명특성 및 충방전 효율이 우수하여 가장 많이 사용되고 있지만, 구조적 안정성이 낮아 전지의 고용량화 기술에 적용되기에는 한계가 있다.Accordingly, the positive electrode active material for lithium secondary batteries currently being actively researched and developed is LiCoO 2 having a layered structure. LiCoO 2 is most commonly used due to its excellent lifespan characteristics and charge and discharge efficiency. However, LiCoO 2 has a low structural stability and thus is not applicable to high capacity technology of batteries.
이를 대체하기 위한 양극활물질로서, LiNiO2, LiMnO2, LiMn2O4, LiFePO4 또는 Li(NixCoyMnz)O2 등의 다양한 리튬 전이금속 산화물이 개발되었다. 이중, LiNiO2의 경우 높은 방전용량의 전지 특성을 나타내는 장점이 있으나, 간단한 고상반응으로는 합성이 어렵고, 열적 안정성 및 사이클 특성이 낮은 문제점이 있다. 또, LiMnO2, 또는 LiMn2O4 등의 리튬 망간계 산화물은 열적안전성이 우수하고, 가격이 저렴하다는 장점이 있지만, 용량이 작고, 고온 특성이 낮은 문제점이 있다. 특히, LiMn2O4의 경우 저가격 제품에 일부 상품화가 되어 있으나, Mn3 +로 인한 구조변형(Jahn-Teller distortion) 때문에 수명특성이 좋지 않다. 또한, LiFePO4는 낮은 가격과 안전성이 우수하여 현재 하이브리드 자동차(hybrid electric vehicle, HEV)용으로 많은 연구가 이루어지고 있으나, 낮은 전도도로 인해 다른 분야에 적용은 어려운 실정이다.As a cathode active material to replace this, various lithium transition metal oxides such as LiNiO 2 , LiMnO 2 , LiMn 2 O 4 , LiFePO 4 or Li (Ni x CoyMnz) O 2 have been developed. Among them, LiNiO 2 has the advantage of exhibiting battery characteristics of high discharge capacity, but the synthesis is difficult by a simple solid phase reaction, there is a problem of low thermal stability and low cycle characteristics. In addition, lithium manganese oxides such as LiMnO 2 or LiMn 2 O 4 have advantages in that they are excellent in thermal safety and inexpensive, but have a small capacity and low temperature characteristics. In particular, in the case of LiMn 2 O 4 but a part merchandising products to low cost, since the Mn + 3 structure modification (Jahn-Teller distortion) due to the not good life property. In addition, LiFePO 4 has a low price and excellent safety and is currently being studied for a hybrid electric vehicle (HEV), but due to low conductivity it is difficult to apply to other fields.
이 같은 사정으로 인해, LiCoO2의 대체 양극활물질로 최근 가장 각광받고 있는 물질은 Li(NixCoyMnz)O2 (이때, 상기 x, y, z는 각각 독립적인 산화물 조성 원소들의 원자분율로서, 0<x≤1, 0<y≤1, 0<z≤1, 0<x+y+z≤1임)이다. 이 재료는 LiCoO2보다 저가격이며 고용량 및 고전압에 사용될 수 있는 장점이 있으나, 율 특성(rate capability) 및 고온에서의 수명특성이 좋지 않은 단점을 갖고 있다.Due to this situation, Li (NixCoyMnz) O 2 is the most recently attracting attention as an alternative cathode active material for LiCoO 2 . (At this time, X, y, and z are atomic fractions of independent oxide composition elements, respectively, where 0 <x ≦ 1, 0 <y ≦ 1, 0 <z ≦ 1, and 0 <x + y + z ≦ 1. This material is cheaper than LiCoO 2 and has advantages in that it can be used for high capacity and high voltage, but has a disadvantage in that the rate capability and the service life at high temperature are poor.
이에 따라 양극활물질의 내부에 Al, Ti, Sn, Ag 또는 Zn 등의 물질을 도핑(doping)하거나, 또는 전도성이 좋은 금속을 양극활물질 표면에 건식 또는 습식 코팅(coating)하는 방법 등을 통해 양극활물질의 열 안정성, 용량 특성 또는 사이클 특성 등을 개선하려는 많은 시도들이 이루어지고 있으나, 아직 그 개선 정도는 미흡한 실정이다.Accordingly, the positive electrode active material may be doped with Al, Ti, Sn, Ag, or Zn inside the positive electrode active material, or by dry or wet coating a conductive metal on the surface of the positive electrode active material. Many attempts have been made to improve thermal stability, capacity characteristics, or cycle characteristics, but the degree of improvement is still insufficient.
특히 양극활물질을 도핑하는 경우, 양극활물질의 구조 안정성은 향상되지만 용량은 저하되는 문제가 있다. 또, 도핑된 물질의 양극활물질 내 균일 분포가 어렵고, 도핑 물질의 불균일 분포로 인한 활물질 특성 저하의 문제가 있다.In particular, when doping the positive electrode active material, the structural stability of the positive electrode active material is improved, but there is a problem that the capacity is lowered. In addition, the uniform distribution of the doped material in the positive electrode active material is difficult, there is a problem of deterioration of the active material properties due to the non-uniform distribution of the doped material.
본 발명이 해결하고자 하는 제1 기술적 과제는, 음향 공진을 이용하여 활물질 표면에서의 손상 및 특성 저하에 대한 우려 없이 도핑원소로 균일하게 도핑함으로써, 개선된 구조적 안정성을 갖고, 전지 적용시 용량 감소의 최소화 및 사이클 특성 개선 등의 전지 특성을 향상시킬 수 있는 양극활물질의 제조방법을 제공하는 것이다.The first technical problem to be solved by the present invention is to improve the structural stability by uniformly doping with a doping element without fear of damage on the surface of the active material and deterioration of characteristics by using acoustic resonance, thereby improving capacity It is to provide a method for producing a positive electrode active material that can improve battery characteristics such as minimization and improved cycle characteristics.
본 발명이 해결하고자 하는 제2 기술적 과제는, 상기 제조방법에 의해 제조되어, 개선된 구조적 안정성을 가지며, 이로써 전지의 용량, 율(rate) 특성 및 사이클 특성을 개선시킬 수 있는 양극활물질을 제공하는 것이다.The second technical problem to be solved by the present invention is to be prepared by the manufacturing method, having an improved structural stability, thereby providing a cathode active material that can improve the capacity, rate (rate) and cycle characteristics of the battery will be.
본 발명이 해결하고자 하는 제3 기술적 과제는, 상기 양극활물질을 포함하는 양극 및 리튬 이차전지를 제공하는 것이다.The third technical problem to be solved by the present invention is to provide a positive electrode and a lithium secondary battery including the positive electrode active material.
상기 과제를 해결하기 위하여, 본 발명의 일 실시예에 따르면 양극활물질용 금속 전구체와 도핑원소 포함 원료물질을 음향 공진을 이용하여 혼합함으로써 상기 도핑원소로 도핑된 전구체를 준비하는 단계; 및 상기 도핑된 전구체를 리튬 원료물질과 혼합한 후 열처리하는 단계를 포함하며, 상기 양극활물질용 금속 전구체와 도핑원소 포함 원료물질은 2000 내지 5 : 1의 평균 입경비를 갖는 것인 이차전지용 양극활물질의 제조방법을 제공한다.In order to solve the above problems, according to an embodiment of the present invention, preparing a precursor doped with the doping element by mixing the metal precursor for the positive electrode active material and the raw material including the doping element using an acoustic resonance; And mixing the doped precursor with a lithium raw material, followed by heat treatment, wherein the raw material including the metal precursor and the doping element for the positive electrode active material has an average particle size ratio of 2000 to 5: 1. It provides a method of manufacturing.
또한, 본 발명의 다른 일 실시예에 따르면, 상기 제조방법에 의해 제조되어, 금속원소로 도핑된 하기 화학식 2의 리튬 복합금속 산화물을 포함하는 이차전지용 양극활물질을 제공한다:In addition, according to another embodiment of the present invention, there is provided a cathode active material for a secondary battery comprising the lithium composite metal oxide of Formula 2 prepared by the manufacturing method, doped with a metal element:
[화학식 2][Formula 2]
ALi1+aNi1-b-cMbCoc· (1-A)M'sO2 ALi 1 + a Ni 1-bc M b Co c (1-A) M 's O 2
상기 화학식 2에서, In Chemical Formula 2,
M은 Mn 및 Al로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소를 포함하고,M comprises any one or two or more elements selected from the group consisting of Mn and Al,
M'는 Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, 및 Cr로 이루어진 군으로부터 선택되는 어느 하나 또는 둘 이상의 원소를 포함하며, 그리고M 'is any one selected from the group consisting of Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, and Cr or Contains two or more elements, and
0<A<1, 0≤a≤0.33, 0≤b≤0.5, 0≤c≤0.5, 0<s≤0.2이되, 단 b와 c는 동시에 0.5는 아니다.0 <A <1, 0 ≦ a ≦ 0.33, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.5, and 0 <s ≦ 0.2, provided that b and c are not 0.5 at the same time.
아울러, 본 발명의 또 다른 일 실시예에 따르면, 상기 양극활물질을 포함하는 양극 및 리튬 이차전지를 제공한다.In addition, according to another embodiment of the present invention, a cathode and a lithium secondary battery including the cathode active material are provided.
본 발명에 따른 양극활물질의 제조방법은, 도핑된 리튬 복합금속 산화물을 포함하는 양극활물질의 제조시, 음향 공진을 이용함으로써 활물질 표면에서의 손상 및 특성 저하에 대한 우려 없이 도핑원소로 리튬 복합금속 산화물을 균일하게 도핑할 수 있으며, 그 결과 종래 방법에 따른 도핑시에 비해 양극활물질의 구조적 안정성을 더욱 증가시키고, 이로써 전지의 용량, 율(rate) 특성 및 사이클 특성을 더욱 개선시킬 수 있다. 또 상기 방법에 따르면, 종래 방법에 의한 혼합시 발생되는 교반 편차에 의한 데드 존을 최소화할 수 있고, 활물질 제조과정에서의 미분 분진 발생을 억제할 수 있으며, 정량계측이 용이하다. In the method for producing a cathode active material according to the present invention, in the preparation of a cathode active material including a doped lithium composite metal oxide, by using acoustic resonance, the lithium composite metal oxide is used as a doping element without fear of damage on the surface of the active material and deterioration of properties. Can be uniformly doped, and as a result, it is possible to further increase the structural stability of the cathode active material as compared to the doping according to the conventional method, thereby further improving the capacity, rate (rate) and cycle characteristics of the battery. In addition, according to the method, it is possible to minimize the dead zone due to the stirring deviation generated when mixing by the conventional method, to suppress the generation of fine dust in the active material manufacturing process, it is easy to quantitative measurement.
본 명세서에 첨부되는 다음의 도면들은 본 발명의 바람직한 실시예를 예시하는 것이며, 전술한 발명의 내용과 함께 본 발명의 기술사상을 더욱 이해시키는 역할을 하는 것이므로, 본 발명은 그러한 도면에 기재된 사항에만 한정되어 해석되어서는 아니 된다.The following drawings, which are attached to this specification, illustrate preferred embodiments of the present invention, and together with the contents of the present invention serve to further understand the technical spirit of the present invention, the present invention is limited to the matters described in such drawings. It should not be construed as limited.
도 1은 실시예 1-1에서 제조한 도핑 전구체를 주사 전자 현미경(Scanning Electron Microscope, SEM)을 이용하여 관찰한 사진이다.1 is a photograph of the doping precursor prepared in Example 1-1 using a scanning electron microscope (SEM).
도 2는 비교예 1-1에서 제조한 도핑 전구체를 SEM을 이용하여 관찰한 사진이다.Figure 2 is a photograph of the doping precursor prepared in Comparative Example 1-1 using the SEM.
도 3은 비교예 1-2에서 제조한 도핑 전구체를 SEM을 이용하여 관찰한 사진이다. Figure 3 is a photograph of the doping precursor prepared in Comparative Example 1-2 using the SEM.
도 4는 실시예 1-1에 따른 양극활물질의 제조시, 금속 전구체(a)), 도핑된 전구체(b)) 및 양극활물질(c))을 SEM으로 관찰한 사진이다.FIG. 4 is a SEM photograph of the metal precursor (a)), the doped precursor (b), and the cathode active material (c) in the preparation of the cathode active material according to Example 1-1.
도 5는 비교예 1-1에 따른 양극활물질의 제조시, 금속 전구체(a)), 도핑된 전구체(b)) 및 양극활물질(c))을 SEM으로 관찰한 사진이다.5 is a SEM photograph of a metal precursor (a)), a doped precursor (b)) and a cathode active material (c) in the preparation of the cathode active material according to Comparative Example 1-1.
도 6는 실시예 1-2에서 금속 전구체와 도핑원소 포함 원료물질의 혼합물에 대한 음향 공진 처리 후 수득한 도핑 전구체에 대한 SEM 관찰사진이다.FIG. 6 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Example 1-2. FIG.
도 7는 실시예 1-3에서 금속 전구체와 도핑원소 포함 원료물질의 혼합물에 대한 음향 공진 처리 후 수득한 도핑 전구체에 대한 SEM 관찰사진이다.FIG. 7 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Example 1-3. FIG.
도 8는 비교예 1-3에서 금속 전구체와 도핑원소 포함 원료물질의 혼합물에 대한 음향 공진 처리 후 수득한 도핑 전구체에 대한 SEM 관찰사진이다. FIG. 8 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Comparative Example 1-3. FIG.
도 9은 비교예 1-4에서 금속 전구체와 도핑원소 포함 원료물질의 혼합물에 대한 음향 공진 처리 후 수득한 도핑 전구체에 대한 SEM 관찰사진이다. FIG. 9 is an SEM observation photograph of a doping precursor obtained after an acoustic resonance treatment of a mixture of a metal precursor and a doping element-containing raw material in Comparative Example 1-4. FIG.
도 10은 실시예 1-4에 따른 양극활물질의 제조 공정 중, 도핑된 전구체와 리튬 원료물질의 혼합 후 수득한 결과물에 대한 SEM 관찰사진이다. FIG. 10 is an SEM observation photograph of the result obtained after mixing the doped precursor and the lithium raw material during the preparation of the cathode active material according to Example 1-4. FIG.
도 11은 비교예 1-1에 따른 양극활물질의 제조 공정 중, 도핑된 전구체와 리튬 원료물질의 혼합 후 수득한 결과물에 대한 SEM 관찰사진이다.FIG. 11 is an SEM observation photograph of a result obtained after mixing a doped precursor and a lithium raw material during a process of preparing a cathode active material according to Comparative Example 1-1.
도 12는 실시예 1-4 및 비교예 1-5에서 제조한 양극활물질 포함 하프 코인 셀의 방전 특성을 관찰한 그래프이다. 12 is a graph illustrating discharge characteristics of the half-coin cell including the positive electrode active material prepared in Examples 1-4 and Comparative Examples 1-5.
도 13은 실시예 1-6에서 제조한 양극활물질 표면을 관찰한 SEM 사진이다.13 is a SEM photograph of the surface of the positive electrode active material prepared in Example 1-6.
이하, 본 발명에 대한 이해를 돕기 위해 본 발명을 더욱 상세하게 설명한다.Hereinafter, the present invention will be described in more detail to aid in understanding the present invention.
본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 아니되며, 발명자는 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야만 한다.The terms or words used in this specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.
종래 도핑된 양극활물질의 제조는 양극활물질 또는 그 전구체와 도핑원소 포함 원료물질의 건식 혼합 또는 습식 혼합 후 열처리에 의해 수행되었다. 건식 혼합의 경우 공정은 간단하지만, 균일 분산이 되지 않거나 도핑 물질이 응집되기 쉽고, 또 미분 사용시 분진이 발생하는 문제가 있었다. 또, 습식 혼합의 경우 건식에 비해 균일 분산 및 도핑이 가능하지만 공정이 복합한 단점이 있다. 또 상기 건식과 습식 방법 모두 혼합시 교반 편차에 따른 데드 존 발생 그리고 연속 공정에 의한 혼합 가능성의 문제가 있었다.The production of the conventionally doped cathode active material has been carried out by heat treatment after dry mixing or wet mixing of the cathode active material or its precursor and the dopant-containing raw material. In the case of dry mixing, the process is simple, but there is a problem that uniform dispersion or doping material is agglomerated easily, and dust is generated when fine powder is used. In addition, in the case of wet mixing, uniform dispersion and doping are possible as compared to dry, but there are disadvantages in that the process is complex. In addition, both dry and wet methods had problems of dead zone generation due to agitation deviation during mixing and the possibility of mixing by a continuous process.
이에 대해 본 발명에서는 도핑된 양극활물질의 제조시, 양극활물질용 금속 전구체와 도핑원소 포함 원료물질을 음향 공진을 이용하여 혼합하고, 또 상기 음향 공진 조건에 맞추어 금속 전구체와 도핑원소 포함 원료물질의 입자 크기를 함께 제어함으로써, 활물질 표면에서의 손상 및 특성 저하에 대한 우려없이 도핑원소로 상기 금속 전구체를 균일하게 도핑하고, 교반 편차에 의한 데드 존을 최소화할 수 있으며, 그 결과 종래 방법에 따른 도핑시에 비해 양극활물질의 구조적 안정성을 보다 크게 증가시키고, 이로써 전지의 용량, 율(rate) 특성 및 사이클 특성을 더욱 개선시킬 수 있다. In contrast, in the present invention, when preparing the doped cathode active material, the metal precursor for the cathode active material and the doping element-containing raw material are mixed by using acoustic resonance, and the particles of the metal precursor and the doping element-containing raw material according to the acoustic resonance conditions are used. By controlling the size together, the metal precursor can be uniformly doped with a doping element without fear of damage on the surface of the active material and deterioration of properties, and the dead zone due to the stirring variation can be minimized. Compared with this, the structural stability of the positive electrode active material is significantly increased, thereby further improving the capacity, rate characteristics, and cycle characteristics of the battery.
즉, 발명의 일 실시예에 따른 이차전지용 양극활물질의 제조방법은, That is, the method of manufacturing a cathode active material for a secondary battery according to an embodiment of the present invention,
양극활물질용 금속 전구체와 도핑원소 포함 원료물질을 음향 공진을 이용하여 혼합하여, 상기 도핑원소로 도핑된 전구체를 준비하는 단계(단계 1); 및 Preparing a precursor doped with the doping element by mixing the metal precursor for the positive electrode active material and the raw material including the doping element by using acoustic resonance (step 1); And
상기 도핑된 전구체를 리튬 원료물질과 혼합 후 열처리하는 단계(단계 2)를 포함한다. 이때, 상기 양극활물질용 금속 전구체와 도핑원소 포함 원료물질은 2000 내지 5 : 1의 평균입경비를 갖는 것이다.And heat treating the doped precursor with a lithium raw material (step 2). In this case, the raw material including the metal precursor and the doping element for the positive electrode active material is to have an average particle size ratio of 2000 to 5: 1.
이하 각 단계별로 상세히 설명하면, 본 발명의 일 실시예에 따른 양극활물질의 제조방법에 있어서, 단계 1은 도핑된 전구체를 준비하는 단계이다.Hereinafter, each step will be described in detail. In the method for preparing a cathode active material according to an embodiment of the present invention, step 1 is a step of preparing a doped precursor.
구체적으로, 상기 단계 1은 양극활물질용 금속 전구체와 도핑원소 포함 원료물질을 음향 공진(Acoustic Resonance)을 이용하여 혼합함으로써 수행될 수 있다.Specifically, step 1 may be performed by mixing the metal precursor for the positive electrode active material and the raw material including the doping element by using acoustic resonance.
음향 공진에 의한 혼합시, 음향 진동을 혼합 대상 물질에 가하면 음향 에너지가 혼합 대상의 물질을 직접 진동시키게 되는데, 이때 특정 음향 진동의 주파수에서 공진이 발생하고, 공진에 의해 혼합이 일어나게 된다. 이 같은 음향 공진에 의한 혼합은 통상의 유성식 혼합기(planetary mixer)나 고속 혼합기(speed mixer)에 설치된 임펠러 교반에 의한 혼합이나 초음파 혼합과는 다르다. 음향 공진에 의한 혼합은 혼합 과정에서 발생되는 낮은 진동수와 높은 강도의 음향 에너지(acoustic energy)가 빠른 가속도(g-forces)로 혼합계(mixing system) 전체에 걸쳐 균일한 전단력이 발휘하며 전단장(shear field)을 형성함으로써, 급속 유동화 및 분산이 가능하도록 한다. 또, 음향 공진에 의한 혼합은 음향 에너지의 진동수가 초음파 혼합에 비해 수백배 이상 더 낮기 때문에 혼합 규모가 더 클 수 있다. 또, 벌크 유동(bulk flow)에 의해 혼합이 일어나는 임펠러 교반과는 달리, 혼합이 혼합계 전체에 걸쳐 미소 규모의 혼합이 다발적으로 일어나기 때문에 균일 분산이 가능하다.When mixing by acoustic resonance, when acoustic vibration is applied to the material to be mixed, the acoustic energy directly vibrates the material to be mixed. At this time, resonance occurs at a specific acoustic vibration frequency, and mixing occurs by resonance. Such mixing by acoustic resonance is different from mixing by ultrasonic impeller or mixing by impeller agitation provided in a conventional planetary mixer or a speed mixer. Mixing by acoustic resonance has uniform shearing force throughout the mixing system with low acceleration and high intensity acoustic energy (g-forces) generated in the mixing process. shear field) to enable rapid fluidization and dispersion. In addition, the mixing by acoustic resonance may be larger because the frequency of acoustic energy is several hundred times lower than that of ultrasonic mixing. In addition, unlike impeller agitation where mixing takes place by bulk flow, uniform mixing is possible because mixing occurs frequently in small scale mixing throughout the mixing system.
더욱이 본 발명에서 양극활물질용 금속 전구체에 대한 도핑을 위해 사용되는 이트리아 안정화 지르코니아 등과 같은 도핑원소 포함 원료물질은 전구체에 대한 혼화성 및 반응성이 매우 낮기 때문에 균일 도핑이 일어나기 어렵다. 이에 대해 본 발명에서는 음향 공진에 의한 혼합을 수행함으로써 도핑원소 포함 원료물질의 분산성을 높이고, 전구체에 대한 반응성을 높여 전구체 표면에 대한 균일 도핑이 가능하다.Furthermore, in the present invention, a doping element including a doping element such as yttria stabilized zirconia, which is used for doping the metal precursor for the positive electrode active material, does not have uniform doping because of very low miscibility and reactivity to the precursor. On the other hand, in the present invention, by performing the mixing by acoustic resonance, it is possible to increase the dispersibility of the raw material including the doping element, and to increase the reactivity to the precursor to uniformly doping the precursor surface.
상기 음향 공진에 의한 혼합은 통상의 음향 공진기기를 이용하여 수행될 수 있으며, 구체적으로는 어쿠스틱 믹스(acoustic mixer)를 이용하여 수행될 수 있다.Mixing by the acoustic resonance may be performed using a conventional acoustic resonance apparatus, and specifically, may be performed using an acoustic mixer.
음향 공진에 의한 혼합 공정은 사용되는 양극활물질용 금속 전구체와 도핑원소 포함 원료물질의 입자 크기비, 더 나아가 각각의 종류에 따라 혼합 조건이 달라질 수 있으며, 금속 전구체 및 활물질 표면에 대한 손상 및 손실을 최소화하면서 균일하고 우수한 효율로 도핑 효율을 얻기 위해서는 상기 금속 전구체와 도핑원소 포함 원료물질의 입자 크기를 최적화하는 것이 바람직할 수 있으며, 더 나아가 각각의 종류를 함께 최적화하는 것이 보다 바람직할 수 있다.The mixing process by acoustic resonance may have different mixing conditions depending on the particle size ratio of the metal precursor for the positive electrode active material and the raw material including the doping element, and furthermore, the damage and loss to the surface of the metal precursor and the active material. It may be desirable to optimize the particle size of the metal precursor and the doping element-containing raw material in order to obtain doping efficiency with a uniform and excellent efficiency while minimizing, and even more preferably to optimize each type together.
구체적으로 상기 양극활물질용 금속 전구체와 도핑원소 포함 원료물질의 평균입경비는 2000 내지 5 : 1일 수 있으며, 보다 구체적으로는 1000 내지 5 : 1 또는 300 내지 5 : 1, 보다 더 구체적으로는 7.5 내지 5 : 1일 수 있다. 상기한 평균입경비의 조건을 충족할 때 전구체 입자에 대한 손상 및 손실 없이 보다 우수한 효율로 도핑원소 포함 원료물질을 균일 분산시킬 수 있다.Specifically, the average particle size ratio of the metal precursor for the cathode active material and the raw material including the doping element may be 2000 to 5: 1, more specifically 1000 to 5: 1 or 300 to 5: 1, and more specifically 7.5 To 5: 1. When the above conditions of the average particle size are satisfied, the doping element-containing raw material may be uniformly dispersed with superior efficiency without damaging or losing the precursor particles.
보다 구체적으로는 상기 도핑원소 포함 원료물질의 평균입경(D50)이 4nm 내지 5㎛, 혹은 10nm 내지 5㎛, 보다 더 구체적으로는 50nm 내지 3㎛이고, 상기 양극활물질용 금속 전구체의 평균입경(D50)이 10㎛ 내지 20㎛인 조건 하에서 양극활물질용 금속 전구체와 도핑원소 포함 원료물질은, 평균입경비는 2000 내지 5 : 1일 수 있으며, 보다 구체적으로는 1000 내지 5 : 1이거나, 또는 300 내지 5 : 1, 보다 더 구체적으로는 7.5 내지 5 : 1일 수 있다.More specifically, the average particle diameter (D 50 ) of the doping element-containing raw material is 4 nm to 5 μm, or 10 nm to 5 μm, and more specifically 50 nm to 3 μm, and the average particle diameter of the metal precursor for the positive electrode active material ( Under the condition that D 50 ) is 10 μm to 20 μm, the metal precursor for the positive electrode active material and the raw material including the doping element may have an average particle size of 2000 to 5: 1, more specifically, 1000 to 5: 1, or 300 to 5: 1, and more specifically 7.5 to 5: 1.
또, 상기한 입자 크기 조건을 충족하는 양극활물질용 금속 전구체와 도핑원소 포함 원료물질에 대한, 음향 공진에 의한 혼합은 50g 내지 90g의 음향 에너지를 인가함으로써 수행될 수 있으며, 보다 구체적으로는 50g 내지 90g의 음향 에너지를 1분 내지 5분간 인가함으로써 수행될 수 있다. 이때, 상기 단위 g는 중력 가속도를 의미한다(100g=980m/s2).In addition, mixing by acoustic resonance with respect to the metal precursor for the positive electrode active material and the doping element-containing raw material satisfying the particle size condition may be performed by applying acoustic energy of 50 g to 90 g, more specifically 50 g to 90 g of acoustic energy may be performed by applying 1 to 5 minutes. At this time, the unit of g means the acceleration of gravity (100g = 980m / s 2) .
또, 상기 양극활물질용 금속 전구체의 구조에 따라 도핑물질과 금속 전구체의 혼합 양상이 달라질 수 있다.In addition, the mixing mode of the doping material and the metal precursor may vary according to the structure of the metal precursor for the positive electrode active material.
구체적으로, 본 발명에 있어서 상기 양극활물질용 금속 전구체는 복수 개의 1차 입자가 응집된 2차 입자일 수 있으며, 이때 상기 1차 입자는 판상의 형태를 갖는 것일 수 있다. 이때 1차 입자의 판 두께에 따라 2차 입자상의 금속 전구체의 치밀도가 달라지게 되고, 그 결과로서 상기 금속 전구체에 대한 도핑원소의 도핑 양상이 달라질 수 있다. 따라서, 1차 입자의 판상 두께에 따라 상기 음향 공진시 조건을 최적화함으로써 보다 균일하고 효율적인 도핑이 가하다.Specifically, in the present invention, the metal precursor for the positive electrode active material may be secondary particles in which a plurality of primary particles are aggregated, and the primary particles may have a plate-like shape. In this case, the densities of the metal precursors on the secondary particles vary according to the plate thickness of the primary particles, and as a result, the doping aspect of the doping element for the metal precursor may vary. Therefore, more uniform and efficient doping is applied by optimizing the conditions at the time of the acoustic resonance according to the plate thickness of the primary particles.
구체적으로, 양극활물질용 금속 전구체와 도핑원소 포함 원료물질이 상기한 평균입경비를 충족하는 조건 하에서, 상기 양극활물질용 금속 전구체를 형성하는 1차 입자가 판상의 형태를 가지고, 또 판의 평균 두께가 150nm 이하, 보다 구체적으로는 80nm 내지 130nm인 것일 수 있다. 통상, 판 형상을 갖는 1차 입자의 응집으로 이루어진 금속 전구체의 경우, 판 형상의 1차 입자 사이에 공극이 형성되어 2차 입자상의 금속 전구체는 넓은 비표면적을 가질 수 있다. 그러나, 이 경우 1차 입자 사이의 공극 내로 도핑원소의 도입이 용이하지 않기 때문에 도핑되는 도핑원소의 양이 적거나 또는 공극 내가 비어진 채로 남을 수 있으며, 도핑원소에 의한 도핑은 2차 입자상의 금속 전구체 표면에서 주로 일어날 수 있다. 이에 대해 상기 음향 공진에 의한 혼합이 50g 내지 90g의 힘을 1 내지 4분간 인가하여 수행될 경우, 판 상의 1차 입자 사이 공극내로 균일하게 도핑원소가 도입됨으로써 우수한 도핑 효율을 나타낼 수 있으며, 그 결과로서 활물질의 구조 안정성을 향상시킬 수 있다.Specifically, under conditions in which the metal precursor for the positive electrode active material and the raw material including the doping element satisfy the above average particle size ratio, the primary particles forming the metal precursor for the positive electrode active material have a plate-like shape, and the average thickness of the plate. May be 150 nm or less, and more specifically, 80 nm to 130 nm. Usually, in the case of the metal precursor which consists of aggregation of the primary particle which has a plate shape, the space | gap is formed between plate-shaped primary particles, and the metal precursor of secondary particle shape may have a large specific surface area. However, in this case, since the introduction of the doping element into the pores between the primary particles is not easy, the amount of the doping element to be doped may be small or the voids remain empty, and the doping by the doping element may be caused by the secondary particle metal. It can occur mainly at the precursor surface. On the other hand, when the mixing by the acoustic resonance is performed by applying a force of 50g to 90g for 1 to 4 minutes, the doping element is uniformly introduced into the pores between the primary particles on the plate can exhibit excellent doping efficiency, as a result As a result, the structural stability of the active material can be improved.
본 발명에 있어서, '판상' 또는 '판 형태'는 서로 대응 또는 대면하는 두 면이 편평하고, 수평방향의 크기가 수직 방향의 크기보다 큰 입단(aggregate) 구조를 의미하며, 완전한 판 형상은 물론 판 형상과 유사한 형상인 플레이크(flake)상, 비늘상 등도 포함할 수 있다. 또, 상기 판 형상의 1차 입자에 있어서의 평균 판 두께는 주사전자현미경(SEM)을 이용하여 관찰한 1차 입자의 판 두께의 평균값이다. In the present invention, the 'plate shape' or 'plate shape' refers to an aggregate structure in which two surfaces corresponding or facing each other are flat, and the size in the horizontal direction is larger than the size in the vertical direction, Flakes, scales, and the like, which are similar in shape to a plate, may also be included. In addition, the average plate | board thickness in the said plate-shaped primary particle | grains is an average value of the plate | board thickness of the primary particle | grains observed using the scanning electron microscope (SEM).
또, 양극활물질용 금속 전구체와 도핑원소 포함 원료물질이 상기한 평균입경비를 충족하는 조건 하에서, 상기 양극활물질용 금속 전구체를 형성하는 1차 입자가 판상의 형태를 가지고, 또 판의 평균 두께가 150nm 초과, 구체적으로는 200nm 내지 250nm인 경우, 상기 금속 전구체는 판 형태의 1차 입자간 공극이 적은 밀집 구조의 2차 입자상일 수 있다. 통상 상기한 두께를 갖는 1차 입자로 이루어진 전구체의 경우, 두께가 얇은 판 형태의 1차 입자를 포함하는 금속 전구체에 비해 도핑원소의 1차 입자간 공극내 도입이 더 어렵기 때문에 도핑원소가 전구체 표면상에 주로 위치하게 되는데, 이때, 2차 입자상 표면에 국부적으로 도핑원소의 응집이 발생할 수 있다. 이에 대해 상기 음향 공진에 의한 혼합이 60g 내지 90g의 힘을 2분 내지 5분간 인가하여 수행될 경우, 2차 입자상의 전구체 표면 상에 도핑원소가 균일하게 도포된 도포원소의 층이 형성되게 된다. 이 경우, 활물질 표면측에서의 도핑된 리튬 복합금속 산화물의 함량이 증가하고, 그 결과 활물질 표면의 안정성을 높일 수 있다.Further, under conditions where the metal precursor for the positive electrode active material and the raw material including the doping element satisfy the above average particle size ratio, the primary particles forming the metal precursor for the positive electrode active material have a plate-like shape, and the average thickness of the plate When the thickness is greater than 150 nm, specifically, 200 nm to 250 nm, the metal precursor may be a secondary particle having a dense structure with less pore-shaped primary interparticle pores. In the case of a precursor composed of primary particles having the above-described thickness, the doping element is more likely to be introduced into the pores between the primary particles of the doping element than the metal precursor including the thin plate-shaped primary particles. It is mainly located on the surface, where local agglomeration of the doping element may occur locally on the secondary particulate surface. On the other hand, when the mixing by the acoustic resonance is performed by applying a force of 60g to 90g for 2 to 5 minutes, a layer of the coating element on which the doping element is uniformly applied is formed on the precursor surface of the secondary particles. In this case, the content of the doped lithium composite metal oxide on the surface of the active material increases, and as a result, the stability of the surface of the active material can be improved.
한편, 본 발명의 일 실시예에 따른 양극활물질의 제조방법에 있어서, 상기 도핑원소는 구체적으로 Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, 또는 Cr 등일 수 있으며, 이들 중 어느 하나 또는 둘 이상의 원소를 포함할 수 있다.On the other hand, in the method for producing a positive electrode active material according to an embodiment of the present invention, the doping element is specifically Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, Cr or the like, and may include any one or two or more of these.
보다 구체적으로 상기 도핑원소는 활물질 입자의 제조시 소성 공정 중 입자 성장을 억제하여 활물질의 구조적 안정성을 향상시킬 수 있는 주기율표 6족(VIB족)에 해당하는 원소일 수 있다. 보다 더 구체적으로, 상기 도핑원소는 W, Mo 및 Cr로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소일 수 있으며, 보다 구체적으로는 W 및 Cr 로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소일 수 있다. More specifically, the doping element may be an element corresponding to group 6 (VIB group) of the periodic table that can improve the structural stability of the active material by inhibiting particle growth during the firing process during the production of the active material particles. More specifically, the doping element may be any one or two or more elements selected from the group consisting of W, Mo and Cr, more specifically any one or two or more elements selected from the group consisting of W and Cr. Can be.
또, 상기 도핑원소는 보다 구체적으로 주기율표 13족(IIIA족)에 해당하는 원소일 수 있으며, 보다 더 구체적으로는 B, Al, Ga 및 In으로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소일 수 있다.In addition, the doping element may be more specifically an element corresponding to Group 13 (Group IIIA) of the periodic table, and more specifically may be any one or two or more elements selected from the group consisting of B, Al, Ga and In. have.
또, 상기 도핑원소는 보다 구체적으로 3족(IIIB족) 및 4족(IV족) 원소로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소일 수 있으며, 보다 구체적으로는 Ti, Sc, Y, Zr 및 La로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소일 수 있다. In addition, the doping element may be any one or two or more elements selected from the group consisting of Group III (Group IIIB) and Group IV (Group IV) elements, more specifically, Ti, Sc, Y, Zr And La may be any one or two or more elements selected from the group consisting of.
또, 상기 도핑원소는 보다 구체적으로 5족(V족) 원소에 해당하는 원소일 수 있으며, 보다 더 구체적으로는 V, Nb, 및 Ta로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소일 수 있다.In addition, the doping element may be an element corresponding to Group 5 (Group V) elements more specifically, and may be more specifically any one or two or more elements selected from the group consisting of V, Nb, and Ta. .
또, 상기 도핑원소 포함 원료물질은, 상기한 도핑원소를 포함하는 Al2O3와 같은 산화물, 수산화물 또는 옥시수산화물 등일 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다.The doping element-containing raw material may be an oxide, hydroxide, or oxyhydroxide such as Al 2 O 3 including the doping element, and any one or a mixture of two or more thereof may be used.
또, 상기 도핑원소 포함 원료물질는 그 자체로도 우수한 리튬 이온전도성을 가질뿐더러, 이로부터 유래된 금속원소로 도핑시 보다 우수한 도핑 효과와 함께 활물질 구조 안정성을 더욱 향상시킬 수 있는 세라믹계 이온전도체일 수 있다. 상기 세라믹계 이온전도체는 구체적으로 이온전도성의 세라믹 및 메탈세라믹(metal ceramic) 중 적어도 하나를 포함하는 것일 수 있다.In addition, the dopant-containing raw material may be a ceramic-based ion conductor that not only has excellent lithium ion conductivity in itself, but also may further improve the structure stability of the active material with a better doping effect when doping with a metal element derived therefrom. have. The ceramic ion conductor may specifically include at least one of an ion conductive ceramic and a metal ceramic.
상기 이온전도성 세라믹은 구체적으로 이트리아 안정화 지르코니아(yttria stabilized zirconia, YSZ), 칼시아 안정화 지르코니아(calcia stabilized zirconia, CSZ), 스칸디아 안정화 지르코니아(scandia-stabilized zirconia, SSZ) 등과 같은, Y, Ca, Ni 또는 Sc이 도핑된 지르코니아(ZrO2)계 산화물; 가돌리니아 도핑된 세리아(gadolinia doped ceria, GDC), 사마륨 도핑된 세리아(samarium doped ceria, SDC), 이트리아 도핑된 세리아(yttria-doped ceria, YDC) 등과 같은 Gd, Y 또는 Sm이 도핑된 세리아(CeO2)계 산화물; 란타늄 스트론튬 갈레이트 마그네사이트(lanthanum strontium gallate magnesite, LSGM), 란타늄 스트론튬 망가네이트(lanthanum strontium manganite, LSM) 또는 란타늄 스트론튬 코발트 페라이트(lanthanum strontium cobalt ferrite, LSCF) 등과 같은 란타늄계 산화물 등일 수 있으며, 이들 중 1종 단독으로, 또는 2종 이상의 혼합물이 사용될 수 있다. The ion conductive ceramics specifically include Y, Ca, Ni, such as yttria stabilized zirconia (YSZ ) , calcia stabilized zirconia (CSZ), scandia-stabilized zirconia (SSZ), and the like. Or zirconia (ZrO 2 ) -based oxides doped with Sc; Gd, Y or Sm doped ceria such as gadolinia doped ceria (GDC), samarium doped ceria (SDC), yttria-doped ceria (YDC) (CeO 2 ) based oxides; Lanthanum strontium gallate magnesite (LSGM), lanthanum strontium manganite (LSM), or lanthanum strontium cobalt ferrite (LSCF). Species alone or mixtures of two or more may be used.
또, 상기 이온전도성 세라믹에 있어서, 상기 YSZ는 산화지르코늄(지르코니아)에 산화이트륨(이트리아)을 첨가하여 상온에서도 안정하도록 만든 세라믹 재료이다. 상기 YSZ는 지르코니아에 이트리아가 첨가됨으로써 Zr4 + 이온 중 일부가 Y3+로 대체될 수 있다. 이에 따라 4개의 O2-　이온 대신 3개의 O2-　이온으로 대체되며 결과적으로 산소 결핍(oxygen vacancy)이 만들어질 수 있다. 이렇게 생성된 산소 결핍 때문에 YSZ는 O2-이온 전도성를 갖게 되며 온도가 높을수록 전도도가 좋아진다. 구체적으로 상기 YSZ는 Zr(1-x)YxO2 -x/2이며, 이때 0.01≤x≤0.30이고, 보다 구체적으로는 0.08≤x≤0.10일 수 있다. 한편, 본 발명에 있어서 상온은 특별히 정의되지 않은 한 23±5℃에서의 온도범위를 의미한다. 상기 YSZ는 Zr(1-x)YxO2 -x/2(이때, 0.01≤x≤0.30일 수 있고, 보다 구체적으로는 0.08≤x≤0.10)일 수 있다.In the ion conductive ceramics, the YSZ is a ceramic material made of zirconium oxide (zirconia) added with yttrium oxide (yttria) to be stable at room temperature. The YSZ may be part of the yttria is added by being Zr 4 + ions to be substituted for the zirconia are Y 3+. This is replaced by three O 2 ions instead of four O 2 ions, resulting in oxygen vacancy. As a result of this the generated oxygen deficiency YSZ is O 2- ion have jeondoseongreul and the higher the temperature, the better the conductivity. Specifically, YSZ is Zr (1-x) Y x O 2 -x / 2 , where 0.01 ≦ x ≦ 0.30, and more specifically 0.08 ≦ x ≦ 0.10. In addition, in this invention, normal temperature means the temperature range in 23 +/- 5 degreeC unless it is specifically defined. The YSZ is Zr (1-x) Y x O 2 -x / 2 (where, 0.01 ≦ x ≦ 0.30, and more specifically 0.08 ≦ x ≦ 0.10).
한편, 상기 메탈세라믹은 세라믹과 금속분말을 혼합소결하여 제조한 것으로, 내열성과 경도가 높은 세라믹의 특성과 소성변형이나 전기전도도를 갖는 금속의 특성을 모두 갖는다. 구체적으로 상기 메탈세라믹에 있어서 세라믹은 상기한 이온전도성 세라믹일 수 있고, 상기 금속은 니켈, 몰리브덴 또는 코발트 등일 수 있다. 보다 구체적으로는 상기 메탈세라믹은 니켈-이트리아 안정화 지르코니아 서멧(Ni-YSZ cermet) 등의 서멧일 수 있다.On the other hand, the metal ceramic is produced by mixing and sintering the ceramic and the metal powder, and has both the characteristics of a ceramic having high heat resistance and hardness, and a metal having plastic deformation or electrical conductivity. Specifically, in the metal ceramic, the ceramic may be the ion conductive ceramic described above, and the metal may be nickel, molybdenum, cobalt, or the like. More specifically, the metal ceramic may be a cermet such as nickel-yttria stabilized zirconia cermet (Ni-YSZ cermet).
또, 본 발명의 일 실시예에 따른 양극활물질의 제조방법에 있어서, 상기 도핑원소 포함 원료물질의 평균 입경(D50)은 4nm 내지 5㎛일 수 있다. 상기 범위 내의 평균 입경을 가질 때, 음향 공진법에 의한 혼합시 균일 분산이 가능하고, 또 높은 효율로 전구체에 도핑될 수 있다. 보다 구체적으로 상기 도핑원소 포함 원료물질의 평균 입경(D50)은 10nm 내지 5㎛, 보다 더 구체적으로는 50nm 내지 3㎛일 수 있다.In addition, in the positive electrode active material manufacturing method according to an embodiment of the present invention, the average particle diameter (D 50 ) of the doping element containing the raw material may be 4nm to 5㎛. When having an average particle diameter within the above range, it is possible to uniformly disperse during mixing by the acoustic resonance method, and can be doped into the precursor with high efficiency. More specifically, the average particle diameter (D 50 ) of the doping element-containing raw material may be 10nm to 5㎛, even more specifically 50nm to 3㎛.
본 발명에 있어서, 상기 도핑원소 포함 원료물질의 평균 입경(D50)은 입경 분포의 50% 기준에서의 입경으로 정의할 수 있다. 상기 도핑원소 포함 원료물질의 평균 입경(D50)은 레이저 회절법(laser diffraction method)을 이용하여 측정할 수 있으며, 구체적으로 레이저 회절 입도 측정 장치(예를 들어 Microtrac MT 3000)에 도입하여 약 28 kHz의 초음파를 출력 60 W로 조사한 후, 측정 장치에 있어서의 입경 분포의 50% 기준에서의 평균 입경(D50)을 산출할 수 있다.In the present invention, the average particle diameter (D 50 ) of the doping element containing the raw material may be defined as the particle size at 50% of the particle size distribution. The average particle diameter (D 50 ) of the doping element-containing raw material may be measured by using a laser diffraction method, and specifically, introduced into a laser diffraction particle size measuring device (for example, Microtrac MT 3000) to about 28 after examining the kHz ultrasound of 60 W in output, it can be used to calculate the average particle diameter (D 50) of from 50% based on the particle size distribution of the measuring device.
또, 본 발명의 일 실시예에 따른 양극활물질의 제조방법에 있어서, 상기 도핑원소 포함 원료물질은 최종 제조되는 양극활물질에서의 리튬 복합금속 산화물에 도핑되는 도핑원소 포함 원료물질 유래 금속원소의 함량에 따라 그 사용량이 적절히 선택될 수 있다. 구체적으로, 상기 도핑원소 포함 원료물질은 양극활물질용 금속전구체 및 도핑원소 포함 원료물질의 총 함량에 대하여, 500ppm 내지 20,000ppm의 함량으로, 보다 구체적으로는 1,000ppm 내지 8,000ppm의 양으로 사용될 수 있다.In addition, in the method of manufacturing a cathode active material according to an embodiment of the present invention, the doping element-containing raw material is the content of the metal element derived from the doping element-containing raw material doped in the lithium composite metal oxide in the positive electrode active material to be produced finally Therefore, the amount of usage can be appropriately selected. Specifically, the doping element-containing raw material may be used in an amount of 500 ppm to 20,000 ppm, more specifically 1,000 ppm to 8,000 ppm with respect to the total content of the metal precursor for the positive electrode active material and the doping element-containing raw material. .
한편, 본 발명의 일 실시예에 따른 양극활물질의 제조방법에 있어서, 상기 양극활물질용 금속 전구체는 리튬의 가역적인 인터칼레이션 및 디인터칼레이션이 가능한 리튬 복합금속 산화물을 형성할 수 있는 물질로서, 구체적으로 양극활물질용 금속 함유 산화물, 수산화물, 옥시수산화물 또는 인산화물일 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다. 또, 상기 양극활물질용 금속은 구체적으로 니켈, 코발트 망간 및 알루미늄으로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 금속원소를 포함하는 것일 수 있다. On the other hand, in the method for producing a cathode active material according to an embodiment of the present invention, the metal precursor for the cathode active material is a material capable of forming a lithium composite metal oxide capable of reversible intercalation and deintercalation of lithium. For example, the metal-containing oxide, hydroxide, oxyhydroxide or phosphate for the positive electrode active material may be used, and any one or a mixture of two or more thereof may be used. In addition, the metal for the positive electrode active material may specifically include one or two or more metal elements selected from the group consisting of nickel, cobalt manganese and aluminum.
상기 양극활물질용 금속 전구체는 통상의 제조방법에 의해 제조될 수 있다. 일례로, 공침법에 의해 제조될 경우, 양극활물질용 금속 함유 원료물질의 수용액에 암모늄 양이온 함유 착물 형성제와 염기성 화합물을 첨가하여 공침 반응 시킴으로써 제조될 수 있다. The metal precursor for the positive electrode active material may be prepared by a conventional manufacturing method. For example, when prepared by the coprecipitation method, it can be prepared by adding the ammonium cation-containing complex former and the basic compound to the aqueous solution of the metal-containing raw material for the positive electrode active material by coprecipitation reaction.
이때, 상기 양극활물질용 금속 함유 원료물질로는, 목적으로 하는 활물질을 구성하는 리튬 복합금속 산화물의 조성에 따라 결정될 수 있다. 구체적으로는 상기 리튬 복합금속 산화물을 구성하는 금속을 포함하는 수산화물, 옥시수산화물, 질산염, 할로겐화물, 탄산염, 아세트산염, 옥살산염, 시트르산염 또는 황산염 등이 사용될 수 있다. 상기 양극활물질용 금속은 Fe, Ni, Co, Mn, Cr, Zr, Nb, Cu, V, Mo, Ti, Zn, Al, Ga 및 Mg로 이루어지는 군으로부터 선택되는 어느 하나 또는 둘 이상의 혼합 금속일 수 있으며, 보다 구체적으로는 Ni, Co, Mn 및 Al로 이루어지는 군으로부터 선택되는 어느 하나 또는 둘 이상의 혼합금속일 수 있다.In this case, the metal-containing raw material for the positive electrode active material may be determined according to the composition of the lithium composite metal oxide constituting the target active material. Specifically, hydroxides, oxyhydroxides, nitrates, halides, carbonates, acetates, oxalates, citrates or sulfates containing metals constituting the lithium composite metal oxide may be used. The cathode active material metal may be any one or two or more mixed metals selected from the group consisting of Fe, Ni, Co, Mn, Cr, Zr, Nb, Cu, V, Mo, Ti, Zn, Al, Ga and Mg. In more detail, it may be any one or two or more mixed metals selected from the group consisting of Ni, Co, Mn, and Al.
구체적으로, 상기 양극활물질이 리튬 복합금속 화합물로서, 리튬-니켈-코발트-망간계 화합물을 포함하는 경우, 그 전구체로서 양극활물질용 금속 함유 수산화물의 제조를 위한 원료물질로는, 니켈(Ni) 함유 원료물질, 코발트(Co) 함유 원료물질 그리고 망간(Mn) 함유 원료물질이 사용될 수 있다. 상기 각 금속 원소 포함 원료물질은 통상 양극활물질의 제조시 사용되는 것이라면 특별한 제한없이 사용가능하다. 일예로, 상기 Co 함유 원료물질로는 구체적으로 Co(OH)2, CoO, CoOOH, Co(OCOCH3)2ㆍ4H2O, Co(NO3)2ㆍ6H2O 또는 Co(SO4)2ㆍ7H2O 등일 수 있으며, 상기한 화합물 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다.Specifically, when the cathode active material contains a lithium-nickel-cobalt-manganese compound as a lithium composite metal compound, as a precursor, nickel (Ni) is contained as a raw material for producing a metal-containing hydroxide for the cathode active material. Raw materials, cobalt (Co) containing raw materials and manganese (Mn) containing raw materials may be used. Each of the metal element-containing raw materials may be used without particular limitation as long as they are usually used in the production of the positive electrode active material. For example, the Co-containing raw material may be specifically Co (OH) 2 , CoO, CoOOH, Co (OCOCH 3 ) 2 ㆍ 4H 2 O, Co (NO 3 ) 2 ㆍ 6H 2 O or Co (SO 4 ) 2 7H 2 O and the like, any one or a mixture of two or more of the above compounds may be used.
또, 상기 양극활물질용 금속 함유 원료물질은 최종 제조되는 양극활물질에서의 리튬 복합금속 산화물 내 금속들의 함량을 고려하여 적절한 함량비로 사용하는 것이 바람직하다. In addition, the metal-containing raw material for the positive electrode active material is preferably used in an appropriate content ratio in consideration of the content of metals in the lithium composite metal oxide in the final positive electrode active material.
또, 상기 양극활물질용 금속 함유 원료물질은 물; 또는 물과 균일하게 혼합가능한 유기용매(구체적으로 알코올 등)와 물의 혼합물에 용해시켜 수용액으로서 사용될 수 있다.In addition, the metal-containing raw material for the positive electrode active material is water; Or it can be used as an aqueous solution by dissolving in the mixture of the organic solvent (specifically alcohol etc.) and water which can be mixed uniformly with water.
또, 상기 양극활물질용 금속 함유 수산화물의 제조에 사용가능한 암모늄 양이온 함유 착물 형성제는 구체적으로 NH4OH, (NH4)2SO4, NH4NO3, NH4Cl, CH3COONH4, 또는 NH4CO3 등일 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다. 또, 상기 암모늄 양이온 함유 착물 형성제는 수용액의 형태로 사용될 수도 있으며, 이때 용매로는 물; 또는 물과 균일하게 혼합가능한 유기용매(구체적으로 알코올 등)와 물의 혼합물이 사용될 수 있다. In addition, the ammonium cation-containing complex forming agent that can be used to prepare the metal-containing hydroxide for the positive electrode active material is specifically NH 4 OH, (NH 4 ) 2 SO 4 , NH 4 NO 3 , NH 4 Cl, CH 3 COONH 4 , or NH 4 CO 3 and the like, any one or a mixture of two or more thereof may be used. In addition, the ammonium cation-containing complex forming agent may be used in the form of an aqueous solution, wherein the solvent is water; Alternatively, a mixture of water and an organic solvent (specifically alcohol or the like) that can be mixed with water uniformly can be used.
또, 상기 양극활물질용 금속 함유 수산화물의 제조에 사용가능한 염기성 화합물은 NaOH, KOH, 또는 Ca(OH)2 등과 같은 알칼리 금속 또는 알칼리 토금속의 수산화물 또는 이들의 수화물일 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다. 상기 염기성 화합물 역시 수용액의 형태로 사용될 수도 있으며, 이때 용매로는 물, 또는 물과 균일하게 혼합가능한 유기용매(구체적으로 알코올 등)와 물의 혼합물이 사용될 수 있다.In addition, the basic compound usable for the preparation of the metal-containing hydroxide for the positive electrode active material may be a hydroxide of an alkali metal or alkaline earth metal such as NaOH, KOH, or Ca (OH) 2 , or a hydrate thereof, any one or two of them Mixtures of the above may be used. The basic compound may also be used in the form of an aqueous solution, and as the solvent, a mixture of water or an organic solvent (specifically, alcohol, etc.) that can be mixed uniformly with water may be used.
또, 양극활물질용 상기 금속 함유 수산화물의 입자 형성을 위한 공침 반응은, 금속 함유 원료물질의 수용액의 pH가 8 내지 14인 조건에서 수행될 수 있다. 이를 위해 상기 암모늄 양이온 함유 착물 형성제와 염기성 화합물의 첨가량을 적절히 조절하는 것이 바람직하다. 이때 상기 pH값은 액체의 온도 25℃에서의 pH값을 의미한다. 또, 상기 공침반응은 30℃ 내지 60℃의 온도에서 비활성 분위기하에 수행될 수 있다. 상기와 같은 공침반응의 결과로 전구체로서 양극활물질용 금속 함유 수산화물의 입자가 생성되어 수용액 중에 석출되게 된다. In addition, the coprecipitation reaction for forming the particles of the metal-containing hydroxide for the positive electrode active material may be carried out under the condition that the pH of the aqueous solution of the metal-containing raw material is 8 to 14. For this purpose, it is preferable to appropriately adjust the amount of the ammonium cation-containing complex forming agent and the basic compound added. At this time, the pH value means a pH value at the temperature of the liquid 25 ℃. In addition, the coprecipitation reaction may be carried out in an inert atmosphere at a temperature of 30 ℃ to 60 ℃. As a result of the coprecipitation reaction, particles of the metal-containing hydroxide for the positive electrode active material are generated as a precursor and are precipitated in the aqueous solution.
상기와 같은 제조방법에 의해 제조되는 양극활물질용 금속 전구체는 앞서 설명한 바와 같이, 구체적으로, 본 발명에 있어서 상기 양극활물질용 금속 전구체는 복수 개의 1차 입자가 응집된 2차 입자일 수 있으며, 이때 상기 1차 입자는 판 형태를 갖는 것일 수 있다. 이때 제조 공정에서의 반응 속도 조절을 통해 1차 입자의 판 두께를 조절할 수 있다.As described above, the metal precursor for the positive electrode active material prepared by the manufacturing method as described above, specifically, in the present invention, the metal precursor for the positive electrode active material may be secondary particles in which a plurality of primary particles are aggregated. The primary particles may have a plate shape. At this time, the plate thickness of the primary particles can be adjusted by controlling the reaction rate in the manufacturing process.
구체적으로, 상기 양극활물질용 금속 전구체는 판의 평균 두께가 150nm 이하, 보다 구체적으로는 80nm 내지 130nm인 복수 개의 1차 입자가 응집된 2차 입자일 수 있고, 또는 판의 평균 두께가 150nm 초과, 구체적으로는 200nm 내지 250nm인 1차 입자가 응집된 2차 입자일 수 있다. Specifically, the metal precursor for the positive electrode active material may be secondary particles in which a plurality of primary particles having an average thickness of 150 nm or less, more specifically, 80 nm to 130 nm, are aggregated, or an average thickness of a plate is greater than 150 nm, Specifically, the secondary particles may be agglomerated secondary particles of 200 nm to 250 nm.
또, 상기 2차 입자상의 양극활물질용 금속 전구체의 평균 입경(D50)은 4㎛ 내지 30㎛일 수 있으며, 보다 구체적으로는 10㎛ 내지 20㎛일 수 있다. 전구체의 평균 입경이 상기한 범위일 때 보다 효율적인 적용이 가능하다. 본 발명에 있어서, 상기 양극활물질용 금속 전구체의 평균 입경(D50)은 입경 분포의 50% 기준에서의 입경으로 정의할 수 있다. 상기 양극활물질용 금속 전구체의 평균 입경(D50)은 레이저 회절법(laser diffraction method)을 이용하여 측정할 수 있으며, 구체적으로 레이저 회절 입도 측정 장치(예를 들어 Microtrac MT 3000)에 도입하여 약 28 kHz의 초음파를 출력 60 W로 조사한 후, 측정 장치에 있어서의 입경 분포의 50% 기준에서의 평균 입경(D50)을 산출할 수 있다.In addition, the average particle diameter (D 50 ) of the metal precursor for the positive electrode active material may be 4 μm to 30 μm, and more specifically 10 μm to 20 μm. When the average particle diameter of the precursor is in the above range, more efficient application is possible. In the present invention, the average particle diameter (D 50 ) of the metal precursor for the positive electrode active material may be defined as the particle size at 50% of the particle size distribution. The average particle diameter (D 50 ) of the metal precursor for the positive electrode active material may be measured by using a laser diffraction method, and specifically, introduced into a laser diffraction particle size measuring apparatus (for example, Microtrac MT 3000) to about 28 after examining the kHz ultrasound of 60 W in output, it can be used to calculate the average particle diameter (D 50) of from 50% based on the particle size distribution of the measuring device.
상기와 같은 음향 공진 처리에 의해 다양한 금속원소로 도핑된 전구체가 제조되게 된다. 이때 도핑된 금속원소는 금속원소의 위치선호도 및 전구체 물질의 결정 구조에 따라 전구체 내에 균일하게 분포할 수도 있고, 또는 전구체의 입자 중심에서부터 표면까지 함량 분포가 증가 또는 감소하는 농도구배를 가지며 존재할 수도 있으며, 또는 전구체의 표면 측에만 존재할 수도 있다. By the acoustic resonance treatment as described above, precursors doped with various metal elements are prepared. In this case, the doped metal element may be uniformly distributed in the precursor depending on the position preference of the metal element and the crystal structure of the precursor material, or may have a concentration gradient that increases or decreases the content distribution from the particle center of the precursor to the surface. Or on the surface side of the precursor.
다음으로 본 발명의 일 실시예에 따른 양극활물질의 제조방법에 있어서, 단계 2는 상기 단계 1에서 제조한 도핑 전구체를 리튬 원료물질과 혼합 후 열처리하여 양극활물질을 제조하는 단계이다.Next, in the method for manufacturing a cathode active material according to an embodiment of the present invention, step 2 is a step of preparing a cathode active material by mixing the doping precursor prepared in step 1 with a lithium raw material and heat treatment.
상기 리튬 원료물질로는 구체적으로 리튬을 포함하는 수산화물, 옥시수산화물, 질산염, 할로겐화물, 탄산염, 아세트산염, 옥살산염 또는 시트르산염 등을 들 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다. 보다 구체적으로 상기 리튬 원료물질은 Li2CO3, LiNO3, LiNO2, LiOH, LiOHㆍH2O, LiH, LiF, LiCl, LiBr, LiI, CH3COOLi, Li2O, Li2SO4, CH3COOLi 및 Li3C6H5O7로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 화합물을 포함할 수 있다. Specific examples of the lithium raw material include hydroxides, oxyhydroxides, nitrates, halides, carbonates, acetates, oxalates or citrates including lithium, and any one or a mixture of two or more thereof may be used. . More specifically, the lithium raw material is Li 2 CO 3 , LiNO 3 , LiNO 2 , LiOH, LiOHH 2 O, LiH, LiF, LiCl, LiBr, LiI, CH 3 COOLi, Li 2 O, Li 2 SO 4 , CH 3 COOLi and Li 3 C 6 H 5 O 7 It may include any one or two or more compounds selected from the group consisting of.
상기 리튬 원료물질은 최종 제조되는 리튬 복합금속 산화물에서의 리튬 함량에 따라 그 사용량이 결정될 수 있다. The lithium raw material may be used in accordance with the lithium content in the final lithium composite metal oxide to be produced.
상기 도핑된 전구체와 리튬 원료물질의 혼합은 볼밀, 비즈밀, 고압 호모게나이저, 고속 호모게나이저, 또는 초음파 분산 장치 등을 이용한 통상의 혼합 방법에 의해 수행될 수도 있고, 또는 앞서 도핑을 위한 혼합시와 같이 음향 공진에 의해 수행될 수도 있다.Mixing of the doped precursor and the lithium raw material may be performed by a conventional mixing method using a ball mill, a bead mill, a high pressure homogenizer, a high speed homogenizer, an ultrasonic dispersing apparatus, or the like. It may also be performed by acoustic resonance as shown.
구체적으로는 도핑된 전구체와 리튬 원료물질과의 균일 혼합 효과를 고려할 때, 음향 공진에 의해 수행될 수 있으며, 보다 구체적으로는 도핑된 전구체와 리튬 원료물질과의 혼합물에 대해 50g 내지 90g의 음향 에너지를 인가함으로써 수행될 수 있으며, 보다 더 구체적으로는 50g 내지 90g의 음향 에너지를 1분 내지 5분간 인가함으로써 수행될 수 있다. 이때, 상기 단위 g는 중력 가속도를 의미한다(100g=980m/s2).Specifically, considering the homogeneous mixing effect of the doped precursor and the lithium raw material, it may be performed by acoustic resonance, more specifically 50g to 90g of acoustic energy for the mixture of the doped precursor and the lithium raw material It may be carried out by applying, and more specifically, it may be carried out by applying 50g to 90g of acoustic energy for 1 minute to 5 minutes. In this case, the unit g means the acceleration of gravity (100g = 980m / s 2 ).
또, 상기 음향 공진에 의한 혼합시 혼합 효율을 높이기 위해 도핑된 전구체와 리튬 원료물질의 평균입경비를 제어할 수 있으며, 구체적으로는 상기 도핑된 전구체와 리튬 원료물질의 평균입경비는 10:1 내지 3:1일 수 있다.In addition, the average particle size ratio of the doped precursor and the lithium raw material may be controlled to increase the mixing efficiency when mixing by the acoustic resonance. Specifically, the average particle size ratio of the doped precursor and the lithium raw material is 10: 1. To 3: 1.
이어서 상기 도핑된 전구체와 리튬 원료물질의 혼합물에 대한 1차 열처리는 700℃ 내지 950℃에서의 온도에서 수행될 수 있다. 1차 열처리시 온도가 700℃ 미만이면 미반응 원료물질의 잔류로 인해 단위무게당 방전 용량의 저하, 사이클 특성의 저하 및 작동 전압의 저하 우려가 있고, 950℃를 초과하면 부반응물의 생성으로 인해 단위무게당 방전용량의 저하, 사이클 특성의 저하 및 작동 전압의 저하 우려가 있다.Subsequently, the first heat treatment of the mixture of the doped precursor and the lithium raw material may be performed at a temperature of 700 ° C. to 950 ° C. If the temperature is less than 700 ℃ during the first heat treatment, there may be a decrease in discharge capacity per unit weight, cycle characteristics, and a decrease in operating voltage due to residual unreacted raw materials. There is a fear of lowering the discharge capacity per unit weight, lowering of cycle characteristics and lowering of operating voltage.
또, 상기 1차 열처리는 대기 중에서 또는 산소 분위기하에서 실시될 수 있으며, 5시간 내지 30시간 동안 수행될 수 있다. 상기와 같은 조건에서 수행될 때 혼합물의 입자간의 확산 반응이 충분히 이루어질 수 있다.In addition, the primary heat treatment may be performed in the air or under an oxygen atmosphere, and may be performed for 5 hours to 30 hours. When performed under the above conditions, the diffusion reaction between the particles of the mixture can be sufficiently made.
상기 단계 2의 결과로, 리튬 복합금속 산화물 입자를 포함하고, 상기 입자의 표면 측에 존재하는 리튬 복합금속 산화물이 상기 도핑원소 포함 원료물질로부터 유래된 금속원소로 도핑된 양극활물질이 제조된다. As a result of step 2, a cathode active material containing lithium composite metal oxide particles, wherein the lithium composite metal oxide present on the surface side of the particles is doped with a metal element derived from the doping element-containing raw material is prepared.
또, 본 발명의 일 실시예에 따른 양극활물질의 제조방법은 상기 단계 2에서의 1차 열처리 후, 수득된 결과물에 대한 수세 공정을 더 포함할 수 있다.In addition, the method of manufacturing a cathode active material according to an embodiment of the present invention may further include a washing process for the resultant obtained after the first heat treatment in step 2.
상기 수세 공정은 물과의 혼합 등 통상의 수세 방법을 이용하여 수행될 수도 있다. 보다 구체적으로는 상기 결과물과 물과의 혼합이 음향 공진에 의한 혼합으로 수세 공정이 수행될 수 있다. 종래의 수세 방법은 응집 입자 사이 모세관 현상으로 인해 수세 제한성이 있고, 또 과수세시 양극활물질의 특성이 저하되는 문제가 있었다. 이에 대해 음향 공진을 이용하여 물에 의한 수세 공정을 수행할 경우 입자 분산이 용이하여 수세 제한성 없이 우수한 효율로 수세가 이루어 질 수 있고, 또 수세 시간 조정을 통해 양극활물질의 특성 저하를 방지할 수 있다.The washing process may be performed using a conventional washing method such as mixing with water. More specifically, the washing process may be performed by mixing the resultant product with water by mixing by acoustic resonance. The conventional water washing method has a water washing restriction due to the capillary phenomenon between the aggregated particles, and there is a problem in that the characteristics of the positive electrode active material are lowered when overwashing. On the other hand, when performing a water washing process using acoustic resonance, water dispersion can be easily performed, so that water washing can be performed with excellent efficiency without limitation of water washing, and the water washing time can be adjusted to prevent deterioration of the characteristics of the cathode active material. .
수세 시 음향 공진은 20g 내지 90g의 음향 에너지를 10초 내지 30분간 인가함으로써 수행될 수 있다. 상기한 조건으로 수행시 양극활물질의 표면 손상 및 손실에 대한 우려없이, 양극활물질에 잔류하는 미반응 원료물질 및 불순물등을 우수한 효율로 제거할 수 있다. 이때, 상기 단위 g는 중력 가속도를 의미한다(100g=980m/s2).The acoustic resonance at the time of washing may be performed by applying 20g to 90g of acoustic energy for 10 seconds to 30 minutes. When performed under the above conditions, unreacted raw materials and impurities remaining in the cathode active material can be removed with excellent efficiency without concern about surface damage and loss of the cathode active material. In this case, the unit g means the acceleration of gravity (100g = 980m / s 2 ).
또, 본 발명의 일 실시예에 따른 양극활물질의 제조방법은 상기 단계 2에서의 열처리 후 또는 상기 수세 공정 후, 수득된 결과물에 대한 표면처리 공정을 더 포함할 수 있다. In addition, the method of manufacturing a cathode active material according to an embodiment of the present invention may further include a surface treatment process for the resultant obtained after the heat treatment in the step 2 or after the washing process.
상기 표면처리 공정은 통상의 방법에 따라 수행될 수 있으며, 구체적으로는 상기 열처리 후 수득된 결과물과 표면처리제를 음향 공진을 이용하여 혼합 후 추가 열처리(이하 2차 열처리라 함)함으로써 수행될 수 있다.The surface treatment process may be carried out according to a conventional method, specifically, the resultant obtained after the heat treatment and the surface treatment agent may be performed by mixing using an acoustic resonance and then further heat treatment (hereinafter referred to as secondary heat treatment). .
상기 표면처리제는 Me 원료물질(Me는 Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn 및 Zr로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소임)과 혼합 후 열처리하는 경우, Me 원료물질로서 Me 포함 아세트산염, 질산염, 황산염, 할라이드, 황화물, 수산화물, 산화물 또는 옥시수산화물 등이 사용될 수 있다. 일례로, 상기 Me가 B인 경우, 붕산, 사붕산리튬, 산화붕소 및 붕산암모늄 등을 들 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다. 또, 상기 Me가 텅스텐인 경우, 산화텅스텐(VI) 등을 들 수 있다.The surface treatment agent is heat treated after mixing with Me raw material (Me is any one or two or more elements selected from the group consisting of Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn and Zr) In this case, Me-containing acetate, nitrate, sulfate, halide, sulfide, hydroxide, oxide or oxyhydroxide may be used as Me raw material. For example, when Me is B, boric acid, lithium tetraborate, boron oxide, ammonium borate, and the like may be used, and any one or a mixture of two or more thereof may be used. Moreover, when Me is tungsten, tungsten oxide (VI) etc. are mentioned.
표면처리시 음향 공진을 이용함으로써 보다 우수한 효율로 양극활물질 표면에 균일한 표면처리층 형성이 가능하다. 구체적으로 표면처리층 형성을 위한 음향 공진 처리는, 30g 내지 100g의 음향 에너지를 1분 내지 30분간 인가함으로써 수행될 수 있다. 이때, 상기 단위 g는 중력 가속도를 의미한다(100g=980m/s2).By using acoustic resonance during surface treatment, it is possible to form a uniform surface treatment layer on the surface of the cathode active material with better efficiency. Specifically, the acoustic resonance treatment for forming the surface treatment layer may be performed by applying 30 g to 100 g of acoustic energy for 1 to 30 minutes. In this case, the unit g means the acceleration of gravity (100g = 980m / s 2 ).
또, 상기 표면처리층 형성을 위한 2차 열처리는 300℃ 내지 900℃에서 수행될 수 있다. Me 원료물질의 녹는점 반응 온도에 따라 다르게 적용될 수 있으며, 2차 열처리 온도가 300℃ 미만이면 표면처리층 형성이 충분하지 않고, 900℃를 초과하면 과소결에 따른 부반응물 생성의 우려가 있다. In addition, the secondary heat treatment for forming the surface treatment layer may be performed at 300 ℃ to 900 ℃. The melting point of the Me raw material may be differently applied depending on the reaction temperature. If the secondary heat treatment temperature is less than 300 ° C., the surface treatment layer may not be sufficiently formed.
또, 상기 열처리시의 분위기는 특별히 한정되지 않으며, 진공, 불활성 또는 대기 분위기하에서 수행될 수 있다.In addition, the atmosphere during the heat treatment is not particularly limited, and may be performed in a vacuum, inert or air atmosphere.
상기와 같은 표면처리 공정에 의해 활물질 표면 상에 하기 화학식 1의 화합물을 포함하는 표면처리층이 형성될 수 있다:A surface treatment layer including the compound of formula 1 may be formed on the surface of the active material by the surface treatment process as described above:
[화학식 1][Formula 1]
LimMeO(m+n)/2 Li m MeO (m + n) / 2
(상기 화학식 1에서, Me는 Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn 및 Zr로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소이고, 2≤m≤10이고, n은 Me의 산화수이다)(In Formula 1, Me is any one or two or more elements selected from the group consisting of Al, Y, B, W, Hf, Nb, Ta, Mo, Si, Sn and Zr, 2≤m≤10, n is the oxidation number of Me)
상기와 같은 제조방법에 따라 제조된 양극활물질은, 종래 건식 혼합법 또는 습식 혼합법에 의한 도핑시와 비교하여 도핑원소가 균일하게 분산 및 도핑됨으로써, 구조 안전성이 크게 향상되고, 그 결과 전지 적용시 용량 감소가 최소화될 수 있다. 동시에 출력 특성, 율 특성 및 사이클 특성이 더욱 향상될 수 있다.The positive electrode active material prepared according to the above manufacturing method, the doping element is uniformly dispersed and doped as compared to the doping by the conventional dry mixing method or wet mixing method, thereby greatly improving the structural safety, as a result of battery application Dose reduction can be minimized. At the same time, the output characteristics, rate characteristics and cycle characteristics can be further improved.
이에 따라 본 발명의 또 다른 일 실시예에 따르면, 상기한 제조방법에 의해 제조된 양극활물질이 제공된다.Accordingly, according to another embodiment of the present invention, a cathode active material prepared by the above-described manufacturing method is provided.
구체적으로 상기 양극활물질은, 상기 도핑원소로 도핑된 리튬 복합금속 산화물을 포함한다. 보다 구체적으로, 상기 도핑원소로 도핑된 리튬 복합금속 산화물은 전구체 내에 균일하게 분포할 수도 있고, 또는 전구체의 입자 중심에서부터 표면까지 함량 분포가 증가 또는 감소하는 농도구배를 가지며 존재할 수도 있으며, 또는 전구체의 표면측에만 존재할 수도 있다.Specifically, the cathode active material includes a lithium composite metal oxide doped with the doping element. More specifically, the lithium composite metal oxide doped with the doping element may be uniformly distributed in the precursor, or may have a concentration gradient that increases or decreases in content distribution from the particle center of the precursor to the surface, or May exist only on the surface side.
본 발명에 있어서, 리튬 복합금속 산화물 입자의 '표면측'은 입자의 중심을 제외한 표면에 근접한 영역을 의미하며, 구체적으로는 리튬 복합금속 산화물 입자의 표면에서부터 중심까지의 거리, 즉 리튬 복합금속 산화물의 반직경에 대해 입자 표면에서부터 0% 이상 100% 미만, 보다 구체적으로는 입자 표면에서부터 0% 내지 50%, 보다 더 구체적으로는 입자 표면에서부터 0% 내지 30%의 거리에 해당하는 영역을 의미한다. In the present invention, the 'surface side' of the lithium composite metal oxide particles means a region close to the surface except for the center of the particles, specifically, the distance from the surface of the lithium composite metal oxide particles to the center, that is, the lithium composite metal oxide Means a region corresponding to a distance of 0% or more and less than 100% from the particle surface, more specifically 0% to 50% from the particle surface, and more specifically 0% to 30% from the particle surface with respect to the semi-diameter of .
보다 구체적으로, 상기 세라믹 이온전도체의 금속원소에 의해 도핑된 리튬 복합금속 산화물은 하기 화학식 2의 화합물일 수 있다:More specifically, the lithium composite metal oxide doped by the metal element of the ceramic ion conductor may be a compound of Formula 2 below:
[화학식 2][Formula 2]
ALi1+aNi1-b-cMbCoc· (1-A)M'sO2 ALi 1 + a Ni 1-bc M b Co c (1-A) M 's O 2
상기 화학식 2에서, In Chemical Formula 2,
M은 Mn 및 Al로 이루어진 군에서 선택되는 적어도 하나의 금속원소이고, M is at least one metal element selected from the group consisting of Mn and Al,
M'는 도핑원소 포함 원료물질로부터 유래된 금속원소로서, 구체적으로는 Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, 및 Cr로 이루어진 군으로부터 선택되는 어느 하나 또는 이들 중 둘 이상의 혼합 원소일 수 있으며, 보다 구체적으로는 Y, Zr, La, Sr, Ga, Sc, Gd, Sm 및 Ce로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 혼합 원소일 수 있고, 보다 더 구체적으로는 Y 및 Zr로 이루어진 군으로부터 선택되는 적어도 어느 하나의 원소일 수 있으며, 단 M과 M'은 서로 다른 원소일 수 있다.M 'is a metal element derived from a dopant-containing raw material, specifically, Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, It may be any one selected from the group consisting of W, Mo, and Cr or a mixed element of two or more thereof, more specifically in the group consisting of Y, Zr, La, Sr, Ga, Sc, Gd, Sm and Ce It may be any one or two or more mixed elements selected, and more specifically at least one element selected from the group consisting of Y and Zr, provided that M and M 'may be different elements.
또, 상기 화학식 2에서, 0<A<1, 0≤a≤0.33, 0≤b≤0.5, 0≤c≤0.5, 0<s≤0.2이되 b와 c는 동시에 0.5는 아니다. 보다 구체적으로는 상기한 A, b, c 및 s를 충족하는 조건에서 0≤a≤0.09일 수 있고, 보다 더 구체적으로는 b, c 및 s를 충족하는 조건에서 0.9<A<1, a=0일 수 있다. 상기 화학식 2에서 a가 0.33 초과인 경우, 리튬 복합금속 입자에 도핑원소 포함 원료물질을 도핑하는 효과가 통상의 도핑 방법으로 금속원소를 도핑하는 경우에 비해 수명 특성 효과 차이가 약 10% 이내로 현저하지 않을 수 있다. 반면 상기 화학식 2에서 a가 0.09 이하, 특히 0인 경우 리튬 복합금속 산화물 입자에 상기 도핑원소 포함 원료물질을 도핑하는 효과가 통상의 도핑방법으로 금속원소를 도핑하는 경우에 비해 수명 특성 효과가 30% 내지 70%까지 현저할 수 있다. In Formula 2, 0 <A <1, 0 ≦ a ≦ 0.33, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.5, and 0 <s ≦ 0.2, but b and c are not 0.5 at the same time. More specifically, 0 ≦ a ≦ 0.09 under conditions satisfying A, b, c, and s, and more specifically 0.9 <A <1, a = under conditions satisfying b, c, and s. It may be zero. When a is greater than 0.33 in Chemical Formula 2, the effect of doping the raw material including the doping element on the lithium composite metal particles is not more than about 10% of the difference in life characteristic effect compared to the case of doping the metal element by a conventional doping method. You may not. On the other hand, when a is less than or equal to 0.09, particularly 0 in Formula 2, the effect of doping the raw material including the doping element on the lithium composite metal oxide particles is 30% longer than the case of doping the metal element by the conventional doping method. Up to 70%.
또, 상기 화학식 2에서, M'은 리튬 복합금속 산화물의 입자 내에서 입자 표면에서부터 중심으로 갈수록 점진적으로 감소하는 농도구배로 분포할 수도 있다. 이와 같이 양극활물질 입자 내 위치에 따라 도핑되는 금속의 농도가 점진적으로 변화하는 농도구배로 분포함으로써, 활물질내 급격한 상 경계 영역이 존재하지 않아 결정 구조가 안정화되고 열 안정성이 증가하게 된다. 또, 활물질 입자의 표면 측에서 도핑원소가 고농도로 분포하고, 입자 중심으로 갈수록 농도가 감소하는 농도 구배를 포함하는 경우, 열안정성을 나타내면서도 용량의 감소를 방지할 수 있다. In addition, in Formula 2, M 'may be distributed in a concentration gradient gradually decreasing from the particle surface to the center in the particles of the lithium composite metal oxide. As such, the concentration of the doped metal is gradually changed according to the position of the particles of the positive electrode active material, so that there is no abrupt phase boundary region in the active material, so that the crystal structure is stabilized and thermal stability is increased. In addition, when the doping element is distributed at a high concentration on the surface side of the active material particles and includes a concentration gradient in which the concentration decreases toward the particle center, it is possible to prevent a decrease in capacity while exhibiting thermal stability.
구체적으로, 본 발명의 일 실시예에 따른 양극활물질에 있어서, 도핑원소 M'의 농도가 농도구배를 나타내는 경우, 양극활물질내 포함되는 도핑원소 M' 총 원자량을 기준으로, 입자 중심에서부터 10부피% 이내의 영역(이하 간단히 'Rc10 영역' 이라 한다)과, 입자 표면으로부터 10부피% 이내의 영역(이하 간단히 'Rs10 영역' 이라 한다)에서의 M' 의 농도 차이는 10원자% 내지 90원자%일 수 있고, M"의 농도 차이는 10원자% 내지 90원자%일 수 있다.Specifically, in the positive electrode active material according to an embodiment of the present invention, when the concentration of the doping element M 'indicates a concentration gradient, based on the total atomic weight of the doping element M' included in the positive electrode active material, 10% by volume from the center of the particle The difference between the concentrations of M 'in the region within (hereinafter referred to simply as' Rc 10 region') and the region within 10% by volume (hereinafter referred to simply as' Rs 10 region ') is 10 to 90 atoms. %, And the concentration difference of M ″ may be from 10 atomic% to 90 atomic%.
본 발명에 있어서, 양극활물질 입자 내에서의 도핑원소의 농도구배 구조 및 농도는 전자선 마이크로 애널라이저(Electron Probe Micro Analyzer, EPMA), 유도결합 플라스마-원자 방출 분광법(Inductively Coupled Plasma - Atomic Emission Spectrometer, ICP-AES), 또는 비행 시간형 2차 이온 질량분석기(Time of Flight Secondary Ion Mass Spectrometry, ToF-SIMS) 등의 방법을 이용하여 확인할 수 있으며, 구체적으로는 EPMA를 이용하여 양극활물질의 중심에서부터 표면으로 이동하면서 각 금속의 원소비(atomic ratio)를 측정할 수 있다.In the present invention, the concentration gradient structure and the concentration of the doping element in the positive electrode active material particles are determined by the Electron Microbe (Electron Probe Micro Analyzer, EPMA), Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-). AES) or Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and more specifically, using EPMA to move from the center of the cathode active material to the surface. While measuring the atomic ratio of each metal (atomic ratio) can be measured.
또, 본 발명의 일 실시예에 따른 양극활물질은 그 제조시 판 두께가 150nm 초과의 1차 입자로 이루어진 금속 전구체를 사용할 경우, 상기 화학식 2의 리튬 복합금속 산화물로 이루어진 표면처리층을 더 포함할 수 있다. 상기 표면처리층은 리튬 복합금속 산화물 입자의 표면 상에 리튬 복합금속 산화물 입자의 반직경에 대해 0.001 내지 0.1의 두께비로 형성될 수 있으며, 보다 구체적으로는 1nm 내지 1000nm의 두께 범위로 형성될 수 있다.In addition, the cathode active material according to an embodiment of the present invention may further include a surface treatment layer made of the lithium composite metal oxide of Chemical Formula 2 when using a metal precursor made of primary particles having a plate thickness of more than 150 nm. Can be. The surface treatment layer may be formed in a thickness ratio of 0.001 to 0.1 with respect to the semi-diameter of the lithium composite metal oxide particles on the surface of the lithium composite metal oxide particles, more specifically, may be formed in a thickness range of 1nm to 1000nm. .
본 발명의 일 실시예에 따른 상기 양극활물질은 리튬 복합금속 산화물의 1차 입자일 수도 있고, 또는 상기 1차 입자가 조립되어 이루어진 2차 입자 일 수도 있다. 상기 양극활물질이 리튬 복합금속 산화물의 1차 입자일 경우 공기 중의 수분 또는 CO2 등과의 반응에 따른 Li2CO3, LiOH 등의 표면 불순물의 생성이 감소되어 전지 용량 저하 및 가스 발생의 우려가 낮고, 또 우수한 고온 안정성을 나타낼 수 있다. 또, 상기 양극활물질이 1차 입자가 조립된 2차 입자일 경우 출력 특성이 보다 우수할 수 있다. 또 2차 입자일 경우 상기 1차 입자의 평균 입경(D50)은 10nm 내지 200nm일 수 있다. 이 같은 활물질 입자 형태는 활물질을 구성하는 리튬 복합금속 산화물의 조성에 따라 적절히 결정될 수 있다. The cathode active material according to an embodiment of the present invention may be primary particles of a lithium composite metal oxide or secondary particles formed by assembling the primary particles. When the cathode active material is a primary particle of a lithium composite metal oxide, generation of surface impurities such as Li 2 CO 3 , LiOH, and the like caused by reaction with moisture or CO 2 in the air is reduced, thereby reducing battery capacity and gas generation. Also, excellent high temperature stability can be exhibited. In addition, when the cathode active material is secondary particles in which primary particles are assembled, output characteristics may be more excellent. In case of secondary particles, the primary average particle size (D 50) of the particles may be 10nm to 200nm. The form of such active material particles may be appropriately determined according to the composition of the lithium composite metal oxide constituting the active material.
본 발명의 또 다른 일 실시예에 따르면, 상기한 제조방법에 의해 제조된 양극활물질을 포함하는 양극을 제공한다.According to another embodiment of the present invention, there is provided a positive electrode including the positive electrode active material prepared by the above-described manufacturing method.
상기 양극은 상기한 양극활물질을 사용하는 것을 제외하고는 당해 기술 분야에 알려져 있는 통상적인 양극 제조 방법으로 제조할 수 있다. 예를 들면, 양극활물질에 용매, 필요에 따라 바인더, 도전재 또는 분산제를 혼합 및 교반하여 슬러리를 제조한 후, 이를 양극 집전체에 도포(코팅)하고 건조하여 양극활물질층을 형성함으로써 양극을 제조할 수 있다.The positive electrode may be manufactured by a conventional positive electrode manufacturing method known in the art, except for using the positive electrode active material described above. For example, a positive electrode is prepared by mixing and stirring a solvent, a binder, a conductive material, or a dispersant in a positive electrode active material, if necessary, and then coating (coating) and drying the positive electrode current collector to form a positive electrode active material layer. can do.
상기 양극 집전체는 전도성이 높은 금속으로, 상기 양극활물질의 슬러리가 용이하게 접착할 수 있는 금속으로 전지의 전압 범위에서 반응성이 없는 것이면 어느 것이라도 사용할 수 있다. 양극 집전체의 비제한적인 예로는 알루미늄, 니켈 또는 이들의 조합에 의하여 제조되는 호일 등이 있다. The positive electrode current collector is a metal having high conductivity, and may be any metal as long as it is a metal that the slurry of the positive electrode active material can easily adhere to. Non-limiting examples of the positive electrode current collector include a foil made of aluminum, nickel, or a combination thereof.
또, 상기 양극을 형성하기 위한 용매로는 NMP(N-메틸 피롤리돈), DMF(디메틸 포름아미드), 아세톤, 디메틸 아세트아미드 등의 유기 용매 또는 물 등이 있으며, 이들 용매는 단독으로 또는 2종 이상을 혼합하여 사용할 수 있다. 용매의 사용량은 슬러리의 도포 두께, 제조 수율을 고려하여 상기 양극활물질, 바인더 및 도전재를 용해 및 분산시킬 수 있는 정도이면 충분하다.In addition, the solvent for forming the positive electrode includes an organic solvent such as NMP (N-methyl pyrrolidone), DMF (dimethyl formamide), acetone, dimethyl acetamide or water, and these solvents are used alone or 2 It can mix and use species. The amount of the solvent used is sufficient to dissolve and disperse the positive electrode active material, the binder, and the conductive material in consideration of the coating thickness of the slurry and the production yield.
상기 바인더로는 비닐리덴플루오라이드-헥사플루오로프로필렌 코폴리머(PVDF-co-HFP), 폴리비닐리덴플루오라이드(polyvinylidenefluoride), 폴리아크릴로니트릴(polyacrylonitrile), 폴리메틸메타크릴레이트(polymethylmethacrylate), 폴리비닐알코올, 카르복시메틸셀룰로오스(CMC), 전분, 히드록시프로필셀룰로오스, 재생 셀룰로오스, 폴리비닐피롤리돈, 테트라플루오로에틸렌, 폴리에틸렌, 폴리프로필렌, 폴리아크릴산, 에틸렌-프로필렌-디엔 모노머(EPDM), 술폰화 EPDM, 스티렌 부타디엔 고무(SBR), 불소 고무, 폴리 아크릴산 (poly acrylic acid) 및 이들의 수소를 Li, Na 또는 Ca 등으로 치환된 고분자, 또는 다양한 공중합체 등의 다양한 종류의 바인더 고분자가 사용될 수 있다. 상기 바인더는 양극활물질층 총 중량에 대하여 1 내지 30 중량%로 포함될 수 있다.The binder may be vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, poly Vinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), liquor Various types of binder polymers can be used, such as fonned EPDM, styrene butadiene rubber (SBR), fluorine rubber, poly acrylic acid and polymers in which hydrogen thereof is replaced with Li, Na or Ca, or various copolymers. have. The binder may be included in an amount of 1 to 30% by weight based on the total weight of the positive electrode active material layer.
상기 도전재는 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 천연 흑연이나 인조 흑연 등의 흑연; 카본블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 파네스 블랙, 램프 블랙, 서멀 블랙, 탄소 나노 튜브 또는 탄소 섬유 등의 탄소계 물질; 구리, 니켈, 알루미늄, 은 등의 금속 분말 또는 금속 섬유; 플루오로카본, 산화아연 또는 티탄산 칼륨 등의 도전성 위스커; 산화 티탄 등의 도전성 금속 산화물; 또는 폴리페닐렌 유도체 등의 전도성 고분자 등을 들 수 있으며, 이들 중 어느 하나 또는 둘 이상의 혼합물이 사용될 수 있다. 상기 도전재는 양극활물질층 총 중량에 대하여 1 내지 30 중량%로 포함될 수 있다.The conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery. Examples of the conductive material include graphite such as natural graphite and artificial graphite; Carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, farnes black, lamp black, thermal black, carbon nanotubes or carbon fibers; Metal powder or metal fibers such as copper, nickel, aluminum, and silver; Conductive whiskers such as fluorocarbon, zinc oxide or potassium titanate; Conductive metal oxides such as titanium oxide; Or conductive polymers such as polyphenylene derivatives, and any one or a mixture of two or more thereof may be used. The conductive material may be included in an amount of 1 to 30 wt% based on the total weight of the cathode active material layer.
본 발명의 또 다른 일 실시예에 따르면, 상기한 제조방법에 의해 제조된 양극활물질을 포함하는 리튬 이차전지를 제공한다.According to another embodiment of the present invention, there is provided a lithium secondary battery including the cathode active material manufactured by the above-described manufacturing method.
상기 리튬 이차전지는 구체적으로 상기 양극, 음극, 상기 양극과 음극 사이에 개재된 세퍼레이터를 포함한다. The lithium secondary battery specifically includes a separator interposed between the positive electrode, the negative electrode, the positive electrode and the negative electrode.
상기 음극에 사용되는 음극 활물질로는 통상적으로 리튬 이온이 흡장 및 방출될 수 있는 탄소재, 리튬 금속, 규소 또는 주석 등을 사용할 수 있다. 바람직하게는 탄소재를 사용할 수 있는데, 탄소재로는 저결정 탄소 및 고결정성 탄소 등이 모두 사용될 수 있다. 저결정성 탄소로는 연화탄소 (soft carbon) 및 경화탄소 (hard carbon)가 대표적이며, 고결정성 탄소로는 천연 흑연, 키시흑연 (Kish graphite), 열분해 탄소 (pyrolytic carbon), 액정피치계 탄소섬유 (mesophase pitch based carbon fiber), 탄소 미소구체 (meso-carbon microbeads), 액정피치 (Mesophase pitches) 및 석유와 석탄계 코크스 (petroleum or coal tar pitch derived cokes) 등의 고온 소성탄소가 대표적이다. 또한, 상기 음극 집전체는 일반적으로 3 ㎛ 내지 500 ㎛의 두께로 만들어진다. 이러한 음극 집전체는, 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 구리, 스테인리스 스틸, 알루미늄, 니켈, 티탄, 소성 탄소, 구리나 스테인리스 스틸의 표면에 카본, 니켈, 티탄, 은 등으로 표면처리한 것, 알루미늄-카드뮴 합금 등이 사용될 수 있다. 또한, 양극 집전체와 마찬가지로, 표면에 미세한 요철을 형성하여 음극 활물질의 결합력을 강화시킬 수도 있으며, 필름, 시트, 호일, 네트, 다공질체, 발포체, 부직포체 등 다양한 형태로 사용될 수 있다.As the negative electrode active material used in the negative electrode, a carbon material, lithium metal, silicon, tin, or the like, in which lithium ions may be occluded and released, may be used. Preferably, a carbon material may be used, and as the carbon material, both low crystalline carbon and high crystalline carbon may be used. Soft crystalline carbon and hard carbon are typical low crystalline carbon, and high crystalline carbon is natural graphite, Kish graphite, pyrolytic carbon, liquid crystal pitch carbon fiber. High temperature calcined carbon such as (mesophase pitch based carbon fiber), meso-carbon microbeads, Mesophase pitches and petroleum or coal tar pitch derived cokes. In addition, the negative electrode current collector is generally made of a thickness of 3 ㎛ to 500 ㎛. Such a negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel Surface-treated with carbon, nickel, titanium, silver, and the like, aluminum-cadmium alloy, and the like can be used. In addition, like the positive electrode current collector, fine concavities and convexities may be formed on the surface to enhance the bonding strength of the negative electrode active material, and may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric.
상기 음극에 사용되는 바인더 및 도전재는 양극과 마찬가지로 당 분야에 통상적으로 사용될 수 있는 것을 사용할 수 있다. 음극은 음극 활물질 및 상기 첨가제들을 혼합 및 교반하여 음극 활물질 슬러리를 제조한 후, 이를 집전체에 도포하고 압축하여 음극을 제조할 수 있다. The binder and the conductive material used for the negative electrode may be used as can be commonly used in the art as the positive electrode. The negative electrode may prepare a negative electrode by mixing and stirring the negative electrode active material and the additives to prepare a negative electrode active material slurry, and then applying the same to a current collector and compressing the negative electrode.
또한, 세퍼레이터로는 종래에 세퍼레이터로 사용된 통상적인 다공성 고분자 필름, 예를 들어 에틸렌 단독중합체, 프로필렌 단독중합체, 에틸렌/부텐 공중합체, 에틸렌/헥센 공중합체 및 에틸렌/메타크릴레이트 공중합체 등과 같은 폴리올레핀계 고분자로 제조한 다공성 고분자 필름을 단독으로 또는 이들을 적층하여 사용할 수 있으며, 또는 통상적인 다공성 부직포, 예를 들어 고융점의 유리 섬유, 폴리에틸렌테레프탈레이트 섬유 등으로 된 부직포를 사용할 수 있으나, 이에 한정되는 것은 아니다.In addition, as the separator, conventional porous polymer films conventionally used as separators, for example, polyolefins such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer and ethylene / methacrylate copolymer, etc. The porous polymer film made of the polymer may be used alone or by laminating them, or a conventional porous nonwoven fabric, for example, a non-woven fabric made of high melting point glass fiber, polyethylene terephthalate fiber, or the like may be used. It is not.
본 발명에서 사용되는 전해질로는 리튬 이차전지 제조시 사용 가능한 유기계 액체 전해질, 무기계 액체 전해질, 고체 고분자 전해질, 겔형 고분자 전해질, 고체 무기 전해질, 용융형 무기 전해질 등을 들 수 있으며, 이들로 한정되는 것은 아니다. Examples of the electrolyte used in the present invention include an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel polymer electrolyte, a solid inorganic electrolyte, a molten inorganic electrolyte, and the like, which can be used in manufacturing a lithium secondary battery. no.
본 발명에서 사용되는 전해질로서 포함될 수 있는 리튬염은 리튬 이차전지용 전해질에 통상적으로 사용되는 것들이 제한 없이 사용될 수 있으며, 예를 들어 상기 리튬염의 음이온으로는 F-, Cl-, Br-, I-, NO3 -, N(CN)2 -, BF4 -, ClO4 -, PF6 -, (CF3)2PF4 -, (CF3)3PF3 -, (CF3)4PF2 -, (CF3)5PF-, (CF3)6P-, CF3SO3 -, CF3CF2SO3 -, (CF3SO2)2N-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, (SF5)3C-, (CF3SO2)3C-, CF3(CF2)7SO3 -, CF3CO2 -, CH3CO2 -, SCN- 및 (CF3CF2SO2)2N-로 이루어진 군에서 선택된 어느 하나일 수 있다. The lithium salt which can be included as an electrolyte used in the present invention can be used without limitation, those which are commonly used in a lithium secondary battery electrolyte, such as the lithium salt, the anion is F -, Cl -, Br -, I -, NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, CF 3 CF 2 SO 3 -, (CF 3 SO 2) 2 N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 - may be any one selected from the group consisting of -, CH 3 CO 2 -, SCN - , and (CF 3 CF 2 SO 2) 2 N.
상기와 같은 구성을 갖는 리튬 이차전지는, 양극과 음극 사이에 분리막을 개재하여 전극 조립체를 제조하고, 상기 전극 조립체를 케이스 내부에 위치시킨 후, 케이스 내부로 전해액을 주입함으로써 제조될 수 있다.The lithium secondary battery having the above configuration may be manufactured by manufacturing an electrode assembly through a separator between a positive electrode and a negative electrode, placing the electrode assembly inside a case, and then injecting an electrolyte solution into the case.
상기한 바와 같이 본 발명에 따른 양극활물질을 포함하는 리튬 이차전지는 우수한 방전 용량, 출력 특성 및 용량 유지율을 안정적으로 나타내기 때문에, 휴대전화, 노트북 컴퓨터, 디지털 카메라 등의 휴대용 기기, 및 하이브리드 전기자동차 등의 전기 자동차 분야 등에 유용하다.As described above, since the lithium secondary battery including the cathode active material according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity retention rate, portable devices such as mobile phones, notebook computers, digital cameras, and hybrid electric vehicles It is useful in the field of electric vehicles.
이에 따라, 본 발명의 다른 일 구현예에 따르면, 상기 리튬 이차전지를 단위 셀로 포함하는 전지 모듈 및 이를 포함하는 전지팩을 제공한다. Accordingly, according to another embodiment of the present invention, a battery module including the lithium secondary battery as a unit cell and a battery pack including the same are provided.
상기 전지모듈 또는 전지팩은 파워 툴(Power Tool); 전기자동차(Electric Vehicle, EV), 하이브리드 전기자동차(Hybrid Electric Vehicle, HEV), 및 플러그인 하이브리드 전기자동차(Plug-in Hybrid Electric Vehicle, PHEV)를 포함하는 전기차; 또는 전력 저장용 시스템 중 어느 하나 이상의 중대형 디바이스 전원으로 이용될 수 있다.The battery module or the battery pack is a power tool (Power Tool); Electric vehicles including electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs); Or it can be used as a power source for any one or more of the system for power storage.
이하, 본 발명을 구체적으로 설명하기 위해 실시예를 들어 상세하게 설명하기로 한다. 그러나, 본 발명에 따른 실시예는 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 아래에서 기술하는 실시예에 한정되는 것으로 해석되어서는 안 된다. 본 발명의 실시예는 당업계에서 평균적인 지식을 가진 자에게 본 발명을 보다 완전하게 설명하기 위해서 제공되는 것이다.Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.
실시예 1-1: 양극활물질의 제조Example 1-1 Preparation of Cathode Active Material
Ni0 . 83Co0 . 11Mn0 .06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)에 대해 이트리아 안정화 지르코니아 (YSZ) 나노분말(D50=50nm)을 2000ppm의 농도로 첨가한 후 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 60g의 음향에너지를 2분간 인가하여, YSZ 도핑원소 포함 원료물질 유래 세라믹 원소(Y 및 Zr)가 도핑된 전구체를 수득하였다.Ni 0 . 83 Co 0 . 11 Mn 0 .06 (OH) 2 precursor (D 50 = 15㎛, plate form primary average plate thickness = 95nm in size) yttria-stabilized zirconia (YSZ) nanopowders for a concentration of 2000ppm (D 50 = 50nm) After the addition, the acoustic energy of 60g was applied for 2 minutes using an acoustic mixer (LabRAM II) to obtain a precursor doped with ceramic elements (Y and Zr) derived from the raw material including the YSZ doping element.
도핑된 전구체에 대해 LiOH를 1.02의 몰비로 첨가하고 블렌딩 믹서를 이용하여 15000rpm으로 10분간 혼합한 후, 산소 분위기에서 800℃로 열처리하여, Y 및 Zr이 도핑된 리튬 복합금속 산화물의 양극활물질을 제조하였다. LiOH was added at a molar ratio of 1.02 to the doped precursor and mixed for 10 minutes at 15000 rpm using a blending mixer, followed by heat treatment at 800 ° C. in an oxygen atmosphere to prepare a positive electrode active material of a lithium composite metal oxide doped with Y and Zr. It was.
비교예 1-1: 양극활물질의 제조Comparative Example 1-1: Preparation of Cathode Active Material
Ni0 . 83Co0 . 11Mn0 .06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)에 대해 YSZ 나노분말(D50=50nm)을 2000ppm의 농도로 첨가한 후 블렌딩 믹서를 이용하여 15000rpm으로 10분간 혼합하여 도핑된 전구체를 수득하였다.Ni 0 . 83 Co 0 . 11 Mn 0 .06 (OH) 2 precursor (D 50 = 15㎛, plate form primary average plate thickness = 95nm particle) YSZ nanopowder on followed by the addition of (D 50 = 50nm) at a concentration of 2000ppm blending mixer 10 minutes at 15000rpm was mixed to obtain a doped precursor.
혼합된 전구체에 대해 LiOH를 1.02의 몰비로 첨가하고 블렌딩 믹서를 이용하여 15000rpm으로 10분간 혼합한 후 산소 분위기에서 800℃로 2차 열처리하여 양극활물질을 제조하였다. LiOH was added to the mixed precursor at a molar ratio of 1.02, and the mixture was mixed at 15000 rpm for 10 minutes using a blending mixer, followed by secondary heat treatment at 800 ° C. in an oxygen atmosphere to prepare a cathode active material.
비교예 1-2: 양극활물질의 제조Comparative Example 1-2: Preparation of Cathode Active Material
탈이온수를 기계식 교반기(mechanical stirrer)로 교반하면서 YSZ 나노분말(D50=50nm)을 2,000ppm의 농도로 첨가하여 균질한 상태로 만들었다. 이후 Ni0.83Co0.11Mn0.06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)를 투입하고 50rpm으로 30분간 혼합하였다. 혼합된 용액을 여과한 후 130℃에서 12시간 건조하였다.While deionized water was stirred with a mechanical stirrer, YSZ nanopowder (D 50 = 50 nm) was added at a concentration of 2,000 ppm to make it homogeneous. Since Ni 0.83 Co 0.11 Mn 0.06 (OH) 2 precursor (D 50 = 15㎛, average plate thickness of the plate-shaped primary particles = 95nm) was added and mixed for 30 minutes at 50rpm. The mixed solution was filtered and dried at 130 ° C. for 12 hours.
결과로 수득된 반응물에 대해 LiOH를 1.02의 몰비로 첨가하고 블렌딩 믹서를 이용하여 15000rpm으로 10분간 혼합한 후 산소 분위기에서 800℃로 소성하여 양극활물질을 제조하였다.LiOH was added to the resultant reactant at a molar ratio of 1.02, and the mixture was mixed at 15000 rpm for 10 minutes using a blending mixer, and then calcined at 800 ° C. in an oxygen atmosphere to prepare a cathode active material.
실험예 1Experimental Example 1
상기 실시예 1-1 및 비교예 1-1, 1-2에 따른 양극활물질의 제조시, 도핑된 전구체를 주사전자 현미경으로 관찰하였다. 그 결과를 하기 도 1 내지 3에 각각 나타내었다. In preparing the cathode active materials according to Example 1-1 and Comparative Examples 1-1 and 1-2, the doped precursor was observed under a scanning electron microscope. The results are shown in FIGS. 1 to 3, respectively.
확인 결과, 종래 건식 공정(비교예 1-1) 및 습식 공정(비교예 1-2)에 비해 음향 공진법을 이용할 경우 분산에 보다 유리하여 응집이 적고, 전구체 표면에 보다 균일하게 도핑됨을 확인할 수 있다. 또 음향 공진법의 이용시 전구체 표면에서의 손상이 없음을 확인할 수 있으며, 공정시간도 단축되었다. As a result, when the acoustic resonance method is used compared to the conventional dry process (Comparative Example 1-1) and wet process (Comparative Example 1-2), it is more favorable for dispersion and less cohesion, and it can be confirmed that the precursor surface is more uniformly doped. have. In addition, it can be seen that there is no damage on the surface of the precursor when the acoustic resonance method is used, and the process time is also shortened.
또, 상기 실시예 1-1 및 비교예 1-1에 따른 양극활물질의 제조시, 사용된 금속 전구체(a)), 도핑 공정 후 도핑된 전구체(b)), 그리고 최종 제조된 양극활물질(c))을 각각 SEM으로 관찰하였다. 그 결과를 도 4 및 5에 나타내었다. In addition, in the preparation of the cathode active material according to Example 1-1 and Comparative Example 1-1, the metal precursor (a) used, the doped precursor (b) after the doping process), and the final cathode active material (c )) Were respectively observed by SEM. The results are shown in FIGS. 4 and 5.
실시예 1-2, 1-3, 및 비교예 1-3, 1-4 : 양극활물질의 제조Examples 1-2, 1-3, and Comparative Examples 1-3, 1-4: Preparation of Cathode Active Material
전구체 입자와 도핑원소 포함 원료물질의 입자크기를 하기 표 1에 기재된 바와 같이 다양하게 변화시키는 것을 제외하고는 상기 실시예 1에서와 동일한 방법으로 수행하여 양극활물질을 제조하였다.A positive electrode active material was prepared in the same manner as in Example 1, except that the particle size of the precursor particles and the doping element-containing raw material were variously changed as shown in Table 1 below.
실시예 1-2Example 1-2 실시예 1-3Example 1-3 비교예 1-3Comparative Example 1-3 비교예 1-4Comparative Example 1-4
금속 전구체에서의 1차 입자의 평균 판 두께(nm)Average Plate Thickness of Primary Particles in Metal Precursors (nm) 100100 230230 100100 230230
금속 전구체 평균입경(D50)(㎛)Metal precursor average particle diameter (D 50 ) (㎛) 1515 1515 1515 1515
도핑원소 포함 원료물질의 평균입경(D50)(㎛)Average particle size of raw material including doping element (D 50 ) (㎛) 22 33 3.53.5 44
상기 표 1에서, 제조한 금속 전구체에 있어서의 1차 입자의 평균 판 두께는 주사전자현미경을 이용하여 관찰, 측정하였고, 2차 입자상의 금속 전구체의 평균 입경 및 도핑원소 포함 원료물질의 평균입경은 금속전구체 및 도핑원소 포함 원료물질를 각각 레이저 회절 입도 측정 장치(예를 들어 Microtrac MT 3000)에 도입하여 약 28 kHz의 초음파를 출력 60 W로 조사한 후, 측정 장치에 있어서의 입경 분포의 50% 기준에서의 평균 입경(D50)을 산출한 것이다.In Table 1, the average plate thickness of the primary particles in the prepared metal precursor was observed and measured using a scanning electron microscope, and the average particle diameter of the metal precursor on the secondary particles and the average particle diameter of the raw material including the doping element were A metal precursor and a doping element-containing raw material were respectively introduced into a laser diffraction particle size measuring device (e.g., Microtrac MT 3000) and irradiated with an ultrasonic wave of about 28 kHz at an output of 60 W. The average particle diameter (D 50 ) of was calculated.
실험예 2Experimental Example 2
상기 실시예 1-2, 1-3 및 비교예 1-3, 1-4에서 제조한 전구체를 SEM을 이용하여 관찰하고, 그 결과를 도 6 내지 9에 각각 나타내었다.The precursors prepared in Examples 1-2, 1-3 and Comparative Examples 1-3, 1-4 were observed using SEM, and the results are shown in FIGS. 6 to 9, respectively.
확인결과, D50이 15㎛인 금속 전구체와, D50이 2㎛ 또는 3㎛인 도핑원소 포함 원료물질을 각각 혼합한 실시예 1-2 및 1-3의 경우, 균일 혼합으로 균질상태의 전구체가 관찰된 반면, 전구체 입자와 도핑원소 포함 원료물질의 평균 입경비가 2000 내지 5:1의 조건을 충족하지 않는 평균 입경을 갖는 금속 전구체와 도핑원소 포함 원료물질을 사용한 비교예 1-3 및 1-4의 경우 전구체 표면에 도핑원소 포함 원료물질이 전구체 표면에 부분적으로 응집되어 분포되어 있음을 확인할 수 있으며, 도핑물질이 응집되어 부분적으로 존재하는 것이 관찰되었다.As a result, in Examples 1-2 and 1-3 where a metal precursor having a D 50 of 15 µm and a raw material including a doping element having a D 50 of 2 µm or 3 µm was mixed, the precursors were homogeneous by uniform mixing. Was observed, Comparative Examples 1-3 and 1 using the metal precursor and the doping element-containing raw material having an average particle diameter in which the average particle diameter of the precursor particles and the doping element-containing raw material did not satisfy the conditions of 2000 to 5: 1. In the case of -4, it was confirmed that the doping element-containing raw material was partially aggregated and distributed on the precursor surface on the precursor surface, and the doping material was partially aggregated and present.
실시예 1-4: 양극활물질의 제조Example 1-4 Preparation of Cathode Active Material
Ni0 . 83Co0 . 11Mn0 .06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)에 대해 이트리아 안정화 지르코니아 (YSZ) 나노분말(D50=50nm)을 2000ppm의 농도와 Al2O3 나노분말(D50=50nm)를 2000ppm의 농도로 첨가한 후 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 60g의 음향에너지를 2분간 인가하여, YSZ 도핑원소 포함 원료물질 유래 세라믹 원소(Y 및 Zr)와 Al2O3가 복합 도핑된 전구체를 수득하였다.Ni 0 . 83 Co 0 . 11 Mn 0 .06 (OH) 2 precursor (D 50 = 15㎛, plate form primary average plate thickness = 95nm in size) yttria-stabilized zirconia (YSZ) nanopowders for a concentration of 2000ppm (D 50 = 50nm) And Al 2 O 3 nanopowder (D 50 = 50nm) was added at a concentration of 2000ppm, and then 60 g of acoustic energy was applied for 2 minutes using an acoustic mixer (LabRAM II), and a ceramic element derived from a raw material containing YSZ doped element (Y And a precursor doped with Zr) and Al 2 O 3 complex.
도핑된 전구체에 대해 LiOH를 1.02의 몰비로 첨가하고 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 80g의 음향에너지를 2분간 인가하여 혼합한 후, 산소 분위기에서 800℃로 열처리하여, Y, Zr 및 Al이 도핑된 리튬 복합금속 산화물의 양극활물질을 제조하였다.LiOH was added to the doped precursor at a molar ratio of 1.02, and 80 g of acoustic energy was mixed for 2 minutes using an acoustic mixer (LabRAM II), followed by heat treatment at 800 ° C. in an oxygen atmosphere, and Y, Zr, and Al were doped. A cathode active material of the lithium composite metal oxide was prepared.
비교예 1-5: 양극활물질의 제조Comparative Example 1-5: Preparation of Cathode Active Material
Ni0 . 83Co0 . 11Mn0 .06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)에 대해 이트리아 안정화 지르코니아 (YSZ) 나노분말(D50=50nm)을 2000ppm의 농도와 Al2O3 나노분말(D50=50nm)를 2000ppm의 농도로 첨가한 후 블랜딩 믹서를 이용하여 15000rpm으로 10분간 혼합하여, YSZ 도핑원소 포함 원료물질 유래 세라믹 원소(Y 및 Zr)와 Al2O3가 복합 도핑된 전구체를 수득하였다.Ni 0 . 83 Co 0 . 11 Mn 0 .06 (OH) 2 precursor (D 50 = 15㎛, plate form primary average plate thickness = 95nm in size) yttria-stabilized zirconia (YSZ) nanopowders for a concentration of 2000ppm (D 50 = 50nm) and Al 2 O 3 nano-powder (D 50 = 50nm) for 10 min to mix with 15000rpm using a blending mixer was added at a concentration of 2000ppm, origin include raw materials YSZ doping element of ceramic elements (Y and Zr) and Al 2 A precursor doped with O 3 was obtained.
도핑된 전구체에 대해 LiOH를 1.02의 몰비로 첨가하고 블렌딩 믹서를 이용하여 15000rpm으로 10분간 혼합한 후 산소 분위기에서 800℃로 2차 열처리하여, Y, Zr 및 Al이 도핑된 리튬 복합금속 산화물의 양극활물질을 제조하였다.LiOH was added at a molar ratio of 1.02 to the doped precursor and mixed for 10 minutes at 15000 rpm using a blending mixer, followed by secondary heat treatment at 800 ° C. in an oxygen atmosphere to form a positive electrode of a lithium composite metal oxide doped with Y, Zr, and Al. An active material was prepared.
실험예 3Experimental Example 3
상기 실시예 1-4에서 도핑된 전구체와 리튬 원료물질의 혼합 후 수득된 결과물을 열처리에 앞서 SEM으로 관찰하였다. 그 결과를 도 10에 나타내었다. 비교를 위하여 상기 비교예 1-1에 따른 양극활물질 제조시 도핑된 전구체와 리튬 원료물질의 혼합 후 수득된 결과물에 대해서도 SEM으로 관찰하고, 그 결과를 도 11에 나타내었다.The result obtained after mixing the precursor doped in Example 1-4 and the lithium raw material was observed by SEM prior to the heat treatment. The results are shown in FIG. For comparison, the result obtained after mixing the doped precursor and the lithium raw material when preparing the cathode active material according to Comparative Example 1-1 was observed by SEM, and the results are shown in FIG. 11.
관찰 결과, 실시예 1-4의 경우 비교예 1-1에서의 블랜딩 믹싱 공정에 비해 도핑된 전구체와 리튬 원료물질에 대한 어쿠스틱 믹싱 공정 시간이 짧았음에도 불구하고, 도핑된 전구체와 리튬 원료물질이 균일하게 혼합되어 전구체 입자 표면에 리튬 원료물질이 균일하게 분산 도포되었다. 또 도핑된 전구체 입자 표면 및 벌크에 대한 손상 또한 관찰되지 않았다. 이로부터 도핑된 양극활물질의 제조시 도핑 전구체의 제조공정 외에도, 도핑 후 리튬 원료물질과의 혼합시 음향 공진을 인가함으로써 표면 손상 없이 보다 우수한 표면 특성을 갖는 양극활물질의 제조가 가능함을 확인할 수 있다.As a result, in Example 1-4, the doping precursor and the lithium raw material were uniform even though the acoustic mixing process time for the doped precursor and the lithium raw material was shorter than that of the blending mixing process in Comparative Example 1-1. After mixing, the lithium raw material was uniformly dispersed on the surface of the precursor particles. In addition, no damage to the doped precursor particle surface and bulk was observed. In addition to the manufacturing process of the doping precursor in the preparation of the doped cathode active material from this, it can be seen that it is possible to produce a cathode active material having better surface properties without surface damage by applying acoustic resonance when mixing with the lithium raw material after the doping.
실험예 4Experimental Example 4
상기 실시예 1-4에서 제조한 양극활물질과, 도전재로서 super P 그리고 바인더로서 PVDF를 92.5:2.5:5의 중합비로 혼합하여 양극형성용 조성물을 제조하였다. 이를 알루미늄 호일에 도포한 후 롤프레스를 이용하여 균일하게 압착하고, 130℃ 진공오븐에서 12시간 진공건조하여 리튬 이차전지용 양극을 제조하였다. 상기 양극을 사용하여 2032 규격의 하프코인 셀(half coin cell)을 제조한 후 용량특성을 평가하였다. 이때 비교를 위하여 상기 비교예 1-5에서 제조한 양극활물질을 이용하여 하프코인 셀을 제조하여 사용하였다.The cathode active material prepared in Example 1-4, super P as a conductive material and PVDF as a binder were mixed at a polymerization ratio of 92.5: 2.5: 5 to prepare a composition for forming a cathode. After coating it on an aluminum foil, it was uniformly compressed using a roll press and vacuum dried for 12 hours at 130 ° C. in a vacuum oven to prepare a cathode for a lithium secondary battery. After the production of a half coin cell (half coin cell) of the 2032 standard using the positive electrode was evaluated the capacity characteristics. At this time, the half-coin cell was prepared using the cathode active material prepared in Comparative Example 1-5 for comparison.
구체적으로 용량 특성은 리튬 이차전지를 25℃에서 0.2C의 정전류(CC)로 4.25V가 될 때까지 충전하고, 이후 4.25V의 정전압(CV)으로 충전하여 충전전류가 0.05mAh가 될 때까지 1회째의 충전을 행하였다. 이후 20분간 방치한 다음 0.2C의 정전류로 2.5V가 될 때까지 방전하였다. 이를 통해 방전 용량을 평가하고 비교하였다. 그 결과를 하기 표 2 및 도 12에 나타내었다.Specifically, the capacity characteristics of the lithium secondary battery is charged at 25 ° C. with a constant current (CC) of 0.2C until 4.25V, and then charged with a constant voltage (CV) of 4.25V until the charging current reaches 0.05mAh. The first charge was performed. After standing for 20 minutes, the battery was discharged until it reached 2.5V with a constant current of 0.2C. Through this, the discharge capacity was evaluated and compared. The results are shown in Table 2 and FIG. 12.
방전용량(mAh/g)Discharge Capacity (mAh / g) 방전효율(%)Discharge efficiency (%)
비교예 1-5Comparative Example 1-5 193.6193.6 88.588.5
실시예 1-4Example 1-4 201.6201.6 89.489.4
일반적으로 양극활물질에 대해 도핑을 하게 되면, 전지의 용량특성이 감소하게 되며, 추가적으로 균일하지 못한 도핑물질 또는 도핑원료물질의 잔여 및 응집으로 인해 표면에 불순물로 작용할 수 있는 입자가 생성되어 전지 특성을 감소시킬 수 있다. 실험결과, 실시예 1-4의 양극활물질을 포함하는 전지는, 비교예 1-5에 비해 보다 높은 용량 특성을 나타내었으며, 이로부터 본 발명에 따른 제조방법에 의해 제조된 양극활물질에서의 도핑 효율이 더 높음을 알 수 있다.In general, when the positive electrode active material is doped, the capacity characteristics of the battery are reduced, and additionally, particles which may act as impurities on the surface are generated due to the inhomogeneous doping or doping raw material remaining and agglomeration, thereby improving the battery characteristics. Can be reduced. As a result, the battery containing the positive electrode active material of Example 1-4, showed a higher capacity characteristics than Comparative Example 1-5, from which the doping efficiency in the positive electrode active material prepared by the manufacturing method according to the present invention You can see that this is higher.
실시예Example 1-5:  1-5: 양극활물질의Of positive electrode active material 제조 Produce
Ni0 . 83Co0 . 11Mn0 .06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)에 대해 이트리아 안정화 지르코니아 (YSZ) 나노분말(D50=50nm)을 2000ppm의 농도와 Al2O3 나노분말 (D50=50nm)를 2000ppm의 농도로 첨가한 후 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 60g의 음향에너지를 2분간 인가하여, YSZ 도핑원소 포함 원료물질 유래 세라믹 원소(Y 및 Zr)와 Al2O3 복합 도핑된 전구체를 수득하였다.Ni 0 . 83 Co 0 . 11 Mn 0 .06 (OH) 2 precursor (D 50 = 15㎛, plate form primary average plate thickness = 95nm in size) yttria-stabilized zirconia (YSZ) nanopowders for a concentration of 2000ppm (D 50 = 50nm) And Al 2 O 3 nanopowder (D50 = 50nm) was added at a concentration of 2000 ppm, and then 60 g of acoustic energy was applied for 2 minutes using an acoustic mixer (LabRAM II). Zr) and Al 2 O 3 complex doped precursors were obtained.
도핑된 전구체에 대해 LiOH를 1.03의 몰비로 첨가하고 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 80g의 음향에너지를 2분간 인가하여 혼합한 후, 산소 분위기에서 780℃로 열처리하였다. 열처리후 수득된 결과물을 탈이온수에 분산시킨 후, 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 40g의 음향에너지를 5분간 인가하면서 세척하고, 3분 이상 필터한 후, 130℃ 진공오븐에서 12시간 이상 건조하여 Y, Zr 및 Al이 도핑된 리튬 복합금속 산화물의 양극활물질을 제조하였다.LiOH was added to the doped precursor at a molar ratio of 1.03, and 80 g of acoustic energy was mixed for 2 minutes using an acoustic mixer (LabRAM II), followed by heat treatment at 780 ° C. in an oxygen atmosphere. The resultant obtained after the heat treatment was dispersed in deionized water, and then washed with an acoustic mixer (LabRAM II) while applying 40g of acoustic energy for 5 minutes, filtered for 3 minutes or more, and then dried in a vacuum oven at 130 ° C. for 12 hours or more. A cathode active material of a lithium composite metal oxide doped with Y, Zr, and Al was prepared.
실시예Example 1-6:  1-6: 양극활물질의Of positive electrode active material 제조 Produce
Ni0 . 83Co0 . 11Mn0 .06(OH)2 전구체(D50=15㎛, 판 형태 1차 입자의 평균 판 두께=95nm)에 대해 지르코니아 나노분말 (D50=50nm)을 2000ppm의 농도와 Al2O3 나노분말(D50=50nm)을 2000ppm의 농도로 첨가한 후 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 60g의 음향에너지를 2분간 인가하여 혼합하였다.Ni 0 . 83 Co 0 . 11 Mn 0 .06 (OH) 2 precursor (D 50 = 15㎛, plate form primary average plate thickness = 95nm in size) zirconia nanopowder on (D 50 = 50nm) with a concentration of 2000ppm nano-Al 2 O 3 Powder (D 50 = 50 nm) was added at a concentration of 2000 ppm, and 60 g of acoustic energy was applied and mixed for 2 minutes using an acoustic mixer (LabRAM II).
혼합된 전구체에 대해 LiOH를 1.03의 몰비로 첨가하고 어쿠스틱 믹서(LabRAMⅡ)를 이용하여 80g의 음향에너지를 2분간 인가하여 혼합한 후, 산소 분위기에서 780℃로 열처리하였다. 열처리 후의 결과물을 탈이온수에 분산시킨 후, 기계식 교반기(mechanical stirrer)를 이용하여 400rpm으로 5분간 세척하고, 3분 필터한 후, 130℃ 진공오븐에서 12시간 이상 건조하여 양극활물질을 제조하였다.LiOH was added to the mixed precursor at a molar ratio of 1.03, and 80 g of acoustic energy was applied for 2 minutes using an acoustic mixer (LabRAM II), followed by mixing, followed by heat treatment at 780 ° C. in an oxygen atmosphere. The resultant after the heat treatment was dispersed in deionized water, washed with a mechanical stirrer (mechanical stirrer) for 5 minutes at 400rpm, filtered for 3 minutes, and then dried for 12 hours at 130 ℃ vacuum oven to prepare a cathode active material.
실험예Experimental Example 5 5
상기 실시예 1-5 및 실시예 1-6에서 제조한 양극활물질 5g을 탈이온수 100ml에 첨가하여 5분간 교반한 후, 결과의 용액을 필터링하고, pH 적정기를 이용하여 pH 4가 될 때까지 0.1M HCl을 투입하여, pH 변화에 따른 HCl 소모량을 측정하여 적정점(EP, FP)의 HCl 투입량을 이용하여 하기 수학식 1 및 2에 따라 미반응 LiOH 및 Li2CO3를 계산하였다. 그 결과를 하기 표 3에 나타내었다.5 g of the positive electrode active material prepared in Examples 1-5 and 1-6 were added to 100 ml of deionized water and stirred for 5 minutes, and the resulting solution was filtered, and the pH was adjusted to 0.1 using a pH titrator. M HCl was added, HCl consumption was measured according to the pH change, and the unreacted LiOH and Li 2 CO 3 were calculated according to the following Equations 1 and 2 using the HCl dose of the appropriate point (EP, FP). The results are shown in Table 3 below.
[수학식 1][Equation 1]
LiOH(중량%)=100 × [(2 × EP-FP) × 0.1 X 0.001 × 23.94]/5LiOH (% by weight) = 100 × [(2 × EP-FP) × 0.1 × 0.001 × 23.94] / 5
[수학식 2][Equation 2]
Li2CO3(중량%)=100 × [(FP-EP) × 0.1 × 0.001 × 73.89]/5Li 2 CO 3 (% by weight) = 100 × [(FP-EP) × 0.1 × 0.001 × 73.89] / 5
상기 수학식 1 및 2에서 EP는 evaluation point이고, FP는 fixed point이다. In Equations 1 and 2, EP is an evaluation point and FP is a fixed point.
Li2CO3(중량%)Li 2 CO 3 (% by weight) LiOH(중량%)LiOH (% by weight) 과량의 Li (중량%)Excess Li (wt%) 초기 pHInitial pH
실시예 1-5Example 1-5 0.10770.1077 0.14520.1452 0.25290.2529 11.002311.0023
실시예 1-6Example 1-6 0.19150.1915 0.21060.2106 0.40210.4021 11.662911.6629
실험결과, 세척 공정시 어쿠스틱 믹서를 이용한 실시예 1-5의 양극활물질은, 실시예 1-6에 비해 보다 감소된 불순물의 함량 및 pH값을 나타내었다. As a result, the positive electrode active material of Example 1-5 using the acoustic mixer during the washing process showed a lower content of impurities and a pH value than those of Example 1-6.
또, 상기 실시예 1-6에서 제조한 양극활물질 표면을 SEM으로 관찰하고, 그 결과를 도 13에 나타내었다.In addition, the surface of the positive electrode active material prepared in Example 1-6 was observed by SEM, and the results are shown in FIG.
관찰결과, 통상의 방법으로 제조하여 수세한 실시예 1-6의 양극활물질에서는 표면에 Li 잔여물이 입자간에 관찰되었다.As a result of the observation, in the positive electrode active material of Example 1-6 prepared and washed with conventional methods, Li residues were observed between the particles.
실시예 1-7 양극활물질의 제조Example 1-7 Preparation of Cathode Active Material
YSZ 대신에 Al2O3를 사용하는 것을 제외하고는 상기 실시예 1-5에서와 동일한 방법으로 실시하여, Al으로 도핑된 리튬 복합금속 산화물의 양극활물질을 제조하였다.A positive electrode active material of a lithium composite metal oxide doped with Al was prepared in the same manner as in Example 1-5, except that Al 2 O 3 was used instead of YSZ.
실시예 1-8 양극활물질의 제조Example 1-8 Preparation of Cathode Active Material
YSZ 대신에 SSZ를 사용하는 것을 제외하고는 상기 실시예 1-5에서와 동일한 방법으로 실시하여 SSZ 도핑원소 포함 원료물질 유래 세라믹 원소(Sc 및 Zr)로 도핑된 리튬 복합금속 산화물의 양극활물질을 제조하였다.A positive electrode active material of a lithium composite metal oxide doped with ceramic elements (Sc and Zr) derived from a raw material including an SSZ doping element was prepared in the same manner as in Example 1-5 except that SSZ was used instead of YSZ. It was.
실시예 2-1: 리튬 이차전지의 제조Example 2-1 Fabrication of Lithium Secondary Battery
상기 실시예 1-1에서 제조한 양극활물질 94 중량%, 도전재로 카본 블랙(carbon black) 3 중량%, 그리고 바인더로 폴리비닐리덴 플루오라이드(PVdF) 3 중량%를 용매인 N-메틸-2-피롤리돈(NMP)에 첨가하여 양극 슬러리를 제조하였다. 상기 양극 슬러리를 두께 약 20㎛의 양극 집전체인 알루미늄(Al) 박막에 도포하고, 건조하여 양극을 제조한 후, 롤 프레스(roll press)를 실시하여 양극을 제조하였다.94% by weight of the positive electrode active material prepared in Example 1-1, 3% by weight of carbon black as the conductive material, and 3% by weight of polyvinylidene fluoride (PVdF) as the binder, N-methyl-2 Positive electrode slurry was prepared by addition to pyrrolidone (NMP). The positive electrode slurry was applied to a thin film of aluminum (Al), which is a positive electrode current collector having a thickness of about 20 μm, dried to prepare a positive electrode, and then roll rolled to prepare a positive electrode.
음극 활물질로 흑연 분말 96.3 중량%, 도전재로 super-p 1.0 중량% 및 바인더로 스티렌 부타디엔 고무(SBR) 및 카르복시메틸셀룰로오스(CMC)를 1.5 중량%와 1.2 중량%를 혼합하고 용매인 NMP에 첨가하여 음극 슬러리를 제조하였다. 상기 음극 슬러리를 두께 약 10㎛의 음극 집전체인 구리(Cu) 박막에 도포하고, 건조하여 음극을 제조한 후, 롤 프레스(roll press)를 실시하여 음극을 제조하였다.96.3 wt% graphite powder as negative electrode active material, 1.0 wt% super-p as conductive material, and 1.5 wt% and 1.2 wt% styrene butadiene rubber (SBR) and carboxymethylcellulose (CMC) as binders were added to NMP as a solvent. To prepare a negative electrode slurry. The negative electrode slurry was applied to a thin copper (Cu) thin film, which is a negative electrode current collector having a thickness of about 10 μm, dried to prepare a negative electrode, and then roll-rolled to prepare a negative electrode.
전해질로서 에틸렌카보네이트 및 디에틸카보네이트를 30:70의 부피비로 혼합하여 제조된 비수전해액 용매에 LiPF6를 첨가하여 1M의 LiPF6 비수성 전해액을 제조하였다.LiPF 6 was added to a non-aqueous electrolyte solvent prepared by mixing ethylene carbonate and diethyl carbonate as a electrolyte in a volume ratio of 30:70 to prepare a 1 M LiPF 6 non-aqueous electrolyte.
상기에서 제조한 양극과 음극 사이에 다공성 폴리에틸렌의 분리막을 개재하고, 리튬염 함유 전해액을 주입하여, 셀을 제조하였다.A cell was prepared by injecting a lithium salt-containing electrolyte solution through a separator of porous polyethylene between the positive electrode and the negative electrode prepared above.
실시예 2-2 내지 2-8 리튬 이차전지의 제조Example 2-2 to 2-8 manufacture of lithium secondary battery
상기 실시예 1-2 내지 1-8서 제조한 양극활물질을 각각 사용하는 것을 제외하고는, 실시예 2-1에서와 동일한 방법으로 실시하여 리튬 이차전지를 제조하였다.A lithium secondary battery was manufactured by the same method as in Example 2-1, except for using the cathode active materials prepared in Examples 1-2 to 1-8, respectively.
상기한 실험결과들로부터 본 발명에 따라 음향 공진을 이용하여 도핑원소 포함 원료물질 형성 금속원소로 도핑한 양극활물질은 보다 개선된 구조적 안정성을 가져, 전지 적용시 용량 감소가 최소화되고, 그 결과로 보다 우수한 사이클 특성을 나타냄을 확인하였다.From the above experimental results, according to the present invention, the positive electrode active material doped with a metal element containing a doping element using an acoustic resonance has improved structural stability, thereby minimizing capacity reduction in battery application. It was confirmed to exhibit excellent cycle characteristics.

Claims (19)

  1. 양극활물질용 금속 전구체와 도핑원소 포함 원료물질을 음향 공진을 이용하여 혼합하여, 상기 도핑원소로 도핑된 전구체를 준비하는 단계; 및 Preparing a precursor doped with the doping element by mixing a metal precursor for a positive electrode active material and a raw material including a doping element by using acoustic resonance; And
    상기 도핑된 전구체를 리튬 원료물질과 혼합한 후 열처리하는 단계를 포함하며, Mixing the doped precursor with a lithium raw material and then performing a heat treatment,
    상기 양극활물질용 금속 전구체와 도핑원소 포함 원료물질은 2000 내지 5 : 1의 평균입경비를 갖는 것인 이차전지용 양극활물질의 제조방법.The method of manufacturing a cathode active material for a secondary battery, wherein the raw material including the metal precursor and the doping element for the positive electrode active material has an average particle size ratio of 2000 to 5: 1.
  2. 제 1 항에 있어서,The method of claim 1,
    상기 도핑원소는 Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, 및 Cr로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 원소를 포함하는 것인 이차전지용 양극활물질의 제조방법.The doping element is any one selected from the group consisting of Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, and Cr Or a method for producing a cathode active material for a secondary battery containing two or more elements.
  3. 제 1 항에 있어서,The method of claim 1,
    상기 도핑원소 포함 원료물질은 도핑원소 포함 산화물, 수산화물 및 옥시수산화물로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 혼합물을 포함하는 것인 이차전지용 양극활물질의 제조방법.The doping element-containing raw material is a method of producing a positive electrode active material for a secondary battery comprising a mixture of one or two or more selected from the group consisting of doping element-containing oxide, hydroxide and oxy hydroxide.
  4. 제 1 항에 있어서,The method of claim 1,
    상기 도핑원소 포함 원료물질은 이트리아 안정화 지르코니아, 가돌리니아 도핑된 세리아, 란타늄 스트론튬 갈레이트 마그네사이트, 란타늄 스트론튬 망가네이트, 칼시아 안정화 지르코니아, 스칸디아 안정화 지르코니아, 니켈-이트리아 안정화 지르코니아 서멧 및 Al2O3로 이루어진 군으로부터 선택되는 어느 하나 또는 둘 이상의 혼합물을 포함하는 것인 이차전지용 양극활물질의 제조방법.The dopant-containing raw materials include yttria stabilized zirconia, gadolinia doped ceria, lanthanum strontium gallate magnesite, Lanthanum Strontium Manganate, Calcia Stabilized Zirconia, Scandia Stabilized Zirconia, Nickel-Yttria Stabilized Zirconia Cermet, and Al 2 O 3 . .
  5. 제 1 항에 있어서,The method of claim 1,
    상기 도핑원소 포함 원료물질의 평균입경(D50)은 4nm 내지 5㎛인 것인 이차전지용 양극활물질의 제조방법.The average particle diameter (D 50 ) of the doping element containing the raw material is a manufacturing method of the positive electrode active material for secondary batteries that are 4nm to 5㎛.
  6. 제 1 항에 있어서,The method of claim 1,
    상기 도핑원소 포함 원료물질은 양극활물질용 금속 전구체 및 도핑원소 포함 원료물질의 총 함량에 대하여, 500ppm 내지 10000ppm의 함량으로 사용되는 것인 이차전지용 양극활물질의 제조방법.The doping element-containing raw material is a method for producing a cathode active material for a secondary battery that is used in an amount of 500ppm to 10000ppm with respect to the total content of the metal precursor for the positive electrode active material and the raw material containing the doping element.
  7. 제 1 항에 있어서,The method of claim 1,
    상기 양극활물질용 금속 전구체는, 양극활물질용 금속을 포함하는 산화물, 수산화물 및 옥시수산화물로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 혼합물을 포함하고, The metal precursor for the positive electrode active material includes any one or a mixture of two or more selected from the group consisting of an oxide, a hydroxide and an oxyhydroxide containing a metal for the positive electrode active material,
    상기 양극활물질용 금속은 니켈, 코발트, 망간 및 알루미늄으로 이루어진 군에서 선택되는 어느 하나 또는 둘 이상의 금속원소를 포함하는 것인 이차전지용 양극활물질의 제조방법.Wherein the metal for the positive electrode active material is any one or two or more metal elements selected from the group consisting of nickel, cobalt, manganese and aluminum manufacturing method of a positive electrode active material for secondary batteries.
  8. 제 1 항에 있어서,The method of claim 1,
    상기 양극활물질용 금속 전구체의 평균입경(D50)은 10㎛ 내지 20㎛인 것인 이차전지용 양극활물질의 제조방법.The average particle diameter (D 50 ) of the metal precursor for the positive electrode active material is a method for producing a positive electrode active material for secondary batteries that are 10㎛ to 20㎛.
  9. 제 1 항에 있어서,The method of claim 1,
    상기 음향 공진은 50g 내지 90g의 음향에너지를 인가하여 수행되는 것인 이차전지용 양극활물질의 제조방법.The acoustic resonance is a method of manufacturing a cathode active material for a secondary battery that is performed by applying the acoustic energy of 50g to 90g.
  10. 제 1 항에 있어서,The method of claim 1,
    상기 양극활물질용 금속 전구체는 판 형태의 1차 입자가 응집되어 이루어진 2차 입자이고, 상기 1차 입자는 평균 판 두께가 150nm 이하인 것이며,The metal precursor for the positive electrode active material is a secondary particle formed by agglomeration of plate-shaped primary particles, and the primary particles have an average plate thickness of 150 nm or less.
    상기 음향 공진은 50g 내지 90g의 음향에너지를 1분 내지 4분간 인가하여 수행되는 것인 이차전지용 양극활물질의 제조방법.The acoustic resonance is a method of manufacturing a cathode active material for a secondary battery that is performed by applying 50g to 90g of acoustic energy for 1 minute to 4 minutes.
  11. 제 1 항에 있어서,The method of claim 1,
    상기 양극활물질용 금속 전구체는 판 형태의 1차 입자가 응집되어 이루어진 2차 입자이고, 상기 1차 입자는 평균 판 두께가 150nm 초과인 것이며,The metal precursor for the positive electrode active material is secondary particles formed by agglomeration of plate-shaped primary particles, and the primary particles have an average plate thickness of more than 150 nm.
    상기 음향 공진은 60g 내지 90g의 음향에너지를 2분 내지 5분간 인가하여 수행되는 것인 이차전지용 양극활물질의 제조방법.The acoustic resonance is a method of manufacturing a cathode active material for a secondary battery that is performed by applying a sound energy of 60g to 90g 2 minutes to 5 minutes.
  12. 제 1 항에 있어서,The method of claim 1,
    상기 음향 공진은 어쿠스틱 믹서를 이용하여 수행되는 것인 이차전지용 양극활물질의 제조방법.The acoustic resonance is a method of manufacturing a cathode active material for a secondary battery that is performed using an acoustic mixer.
  13. 제 1 항에 있어서,The method of claim 1,
    상기 도핑된 전구체와 리튬 원료물질의 혼합은 음향 공진에 의해 수행되는 것인 이차전지용 양극활물질의 제조방법.Mixing of the doped precursor and the lithium raw material is a method of manufacturing a cathode active material for a secondary battery that is performed by acoustic resonance.
  14. 제 1 항에 있어서,The method of claim 1,
    상기 열처리는 700℃ 내지 950℃의 온도에서 수행되는 것인 이차전지용 양극활물질의 제조방법.The heat treatment is a method of manufacturing a cathode active material for a secondary battery that is carried out at a temperature of 700 ℃ to 950 ℃.
  15. 제 1 항에 있어서,The method of claim 1,
    상기 열처리 후 수득된 결과물에 대한 수세 공정을 더 포함하며,Further comprising a washing step for the result obtained after the heat treatment,
    상기 수세 공정은 음향 공진을 이용하여 수행되는 것인 이차전지용 양극활물질의 제조방법.The washing process is a method of manufacturing a cathode active material for a secondary battery that is performed using the acoustic resonance.
  16. 제 1 항에 있어서,The method of claim 1,
    상기 열처리 후 수득된 결과물에 대한 표면처리 공정을 더 포함하며,Further comprising a surface treatment process for the resultant obtained after the heat treatment,
    상기 표면처리 공정은 상기 열처리 후 수득된 결과물과 표면처리제를 음향 공진을 이용하여 혼합 후 열처리 함으로써 수행되는 것인 이차전지용 양극활물질의 제조방법.The surface treatment process is a method of manufacturing a cathode active material for a secondary battery that is performed by heat treatment after mixing the resultant and the surface treatment agent obtained by the heat treatment using the acoustic resonance.
  17. 제 1 항에 따른 제조방법에 의해 제조되며, 금속원소로 도핑된 하기 화학식 2의 리튬 복합금속 산화물을 포함하는 이차전지용 양극활물질:A cathode active material for a secondary battery prepared by the method according to claim 1 and comprising a lithium composite metal oxide of Formula 2 doped with a metal element:
    [화학식 2][Formula 2]
    ALi1+aNi1-b-cMbCoc· (1-A)M'sO2 ALi 1 + a Ni 1-bc M b Co c (1-A) M 's O 2
    상기 화학식 2에서, In Chemical Formula 2,
    M은 Mn 및 Al 중 어느 하나 또는 둘 이상의 원소를 포함하고,M comprises any one or two or more elements of Mn and Al,
    M'는 Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, 및 Cr로 이루어진 군으로부터 선택되는 어느 하나 또는 둘 이상의 원소를 포함하며, 그리고M 'is any one selected from the group consisting of Y, Zr, La, Sr, Ga, Mg, Sc, Gd, Sm, Ca, Ce, Fe, Al, Ti, Ta, Nb, W, Mo, and Cr or Contains two or more elements, and
    0<A<1, 0≤a≤0.33, 0≤b≤0.5, 0≤c≤0.5, 0<s≤0.2이되, b와 c는 동시에 0.5는 아니다.0 <A <1, 0 ≦ a ≦ 0.33, 0 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.5, and 0 <s ≦ 0.2, but b and c are not 0.5 at the same time.
  18. 제 17 항에 따른 양극활물질을 포함하는 양극.A positive electrode comprising the positive electrode active material according to claim 17.
  19. 제 18 항에 따른 양극을 포함하는 리튬 이차전지.A lithium secondary battery comprising the positive electrode according to claim 18.
PCT/KR2017/007114 2016-07-04 2017-07-04 Method for manufacturing positive electrode active material for secondary battery and positive electrode active material for secondary battery, manufactured according to same WO2018008952A1 (en)

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