WO2016153255A1 - Cathode active material and preparation method therefor - Google Patents

Cathode active material and preparation method therefor Download PDF

Info

Publication number
WO2016153255A1
WO2016153255A1 PCT/KR2016/002861 KR2016002861W WO2016153255A1 WO 2016153255 A1 WO2016153255 A1 WO 2016153255A1 KR 2016002861 W KR2016002861 W KR 2016002861W WO 2016153255 A1 WO2016153255 A1 WO 2016153255A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
negative electrode
amorphous carbon
carbon layer
electrode active
Prior art date
Application number
PCT/KR2016/002861
Other languages
French (fr)
Korean (ko)
Inventor
김현욱
김은경
신선영
Original Assignee
주식회사 엘지화학
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020160033216A external-priority patent/KR101817418B1/en
Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to CN201680012017.6A priority Critical patent/CN107408698B/en
Priority to US15/548,969 priority patent/US10326126B2/en
Publication of WO2016153255A1 publication Critical patent/WO2016153255A1/en

Links

Images

Classifications

    • 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
    • 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
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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 negative electrode active material and a method of manufacturing the same.
  • a representative example of an electrochemical device using such electrochemical energy is a secondary battery, and its use area is gradually increasing.
  • portable devices such as portable computers, portable telephones, cameras, and the like
  • secondary batteries exhibit high energy density and operating potential, and have a cycle life.
  • Many studies have been conducted on this long, low self-discharge rate lithium battery and are commercially available and widely used.
  • a typical lithium secondary battery uses graphite as a negative electrode active material, and charging and discharging are performed while repeating a process in which lithium ions of a positive electrode are inserted into and detached from a negative electrode.
  • the theoretical capacity of the battery is different depending on the type of the electrode active material, but as the cycle progresses, the charge and discharge capacity is generally lowered.
  • Patent Document 1 provides a negative electrode for a lithium secondary battery, a method for producing the same, and a lithium secondary battery including the same as a related art related to a negative electrode active material.
  • the conventional negative electrode as described above may have a problem that the electrode resistance is increased by using an excessive amount of the binder.
  • the first technical problem to be solved of the present invention is to provide a negative electrode active material that can produce an electrode with improved adhesion while using less binder.
  • the second technical problem to be solved of the present invention is to provide a method of manufacturing the negative electrode active material.
  • a third technical problem to be solved of the present invention is to provide a negative electrode including the negative electrode active material.
  • a fourth technical problem to be solved of the present invention is to provide a secondary battery having the negative electrode, a battery module and a battery pack having the same.
  • a core comprising natural graphite; And a shell formed on the surface of the core, the shell including a roughened amorphous carbon layer, thereby providing an anode active material having improved adhesion to the surface.
  • the present invention comprises the steps of forming an amorphous carbon layer on the surface of natural graphite (step 1); And roughening by roughening the surface of the amorphous carbon layer of step 1 (step 2).
  • the present invention is a current collector; And a negative electrode mixture layer including the negative electrode active material formed on the current collector.
  • the present invention also provides a secondary battery, a battery module, and a battery pack including the anode, a cathode coated with a cathode mixture including a cathode active material, and an electrolyte.
  • the surface of the negative electrode active material according to the present invention is roughened, it is possible to implement the adhesive force improvement effect even using less binder due to the anchoring effect (anchoring effect) applied on the curved surface between the active material in contact with each other. Therefore, while the high loading of the negative electrode can be realized, the use of a small amount of binder can prevent the increase in resistance.
  • the negative electrode active material according to the present invention has a specific surface area, thereby increasing the access of lithium ions due to the roughened surface, thereby achieving high output of the battery.
  • FIG. 1 is a schematic diagram schematically showing the shape of the negative electrode active material according to an embodiment of the present invention.
  • Figure 2 is a schematic diagram schematically showing a method for producing a negative electrode active material according to an embodiment of the present invention.
  • Figure 3 is a photograph of the negative electrode active material prepared in (a) Example 1 and (b) Comparative Example 1 observed with a scanning electron microscope.
  • Figure 4 is a graph of the results of measuring the adhesion of the negative electrode prepared in Example 1 and Comparative Example 1.
  • FIG. 5 is a graph showing the results of measuring discharge characteristics of the secondary batteries manufactured in Example 1 and Comparative Example 1.
  • FIG. 6 is a schematic diagram schematically showing a spheronization equipment according to an embodiment of the present invention.
  • the material used as the graphite negative electrode material of a secondary battery was spherical natural graphite in which the surface was mostly coated with amorphous carbon.
  • the adhesive force was deteriorated.
  • increasing the content of the binder caused a side effect of increasing the resistance.
  • the present invention is to provide a negative electrode active material that can implement high loading of the negative electrode, excellent adhesion and high power at the same time.
  • a core comprising natural graphite
  • It provides a negative electrode active material comprising a; a shell including a roughened amorphous carbon layer formed on the surface of the core.
  • the core may have a spherical shape having an average particle diameter (D 50 ) of 1 ⁇ m to 20 ⁇ m, and an aspect ratio (length of long axis / length of short axis) may be 1 to 1.5 (
  • the average particle diameter (D 50 ) means the diameter of the particles corresponding to the cumulative volume 50% by volume in the particle size distribution).
  • the core may comprise natural graphite.
  • a crystalline graphite material is mainly used as a negative electrode active material of a secondary battery, and the natural graphite corresponds to crystalline graphite.
  • the natural graphite included in the core may be in the form of a sphere in which granular natural graphite is granulated into a sphere.
  • the amorphous carbon layer constituting the shell may include at least one soft carbon raw material selected from coal-based pitch, petroleum-based pitch, polyvinyl chloride, mesophase pitch, tar, and low molecular weight heavy oil; Polyvinyl alcohol resin, furfuryl alcohol resin, triton, citric acid, stearic acid, sucrose, polyvinylidene fluoride, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, polyvinylpi Lollidon, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), polyacrylic acid, polyacrylic sodium, polyacrylonitrile, glucose, gelatin, sugars, phenol resins, naphthalene resins, polyamide resins, furan resins, polyis At least one hard carbon raw material selected from a mid resin, a cellulose resin, a styrene resin, an epoxy resin and a vinyl chloride resin; Or it can form using the precursor which combined these.
  • the amorphous carbon layer may be included in about 2 to 5% by weight based on the total weight of the negative electrode active material. If the amorphous carbon layer is included in less than 2% by weight based on the entire negative active material, the amorphous carbon layer is too thin so that the natural graphite as a core may be destroyed by the electrolyte, or roughened to the core, 5 In the case where the content is included in an amount of more than% by weight, it is difficult to access lithium ions due to an increase in thickness of the shell.
  • the weight of the amorphous carbon layer may be measured by a thermogravimetric analyzer (TGA) measuring method.
  • TGA thermogravimetric analyzer
  • the weight loss temperature range of the low crystalline coating layer and the crystalline core is different, and thus the coating amount may be measured by the weight ratio. Can be.
  • the shell including the roughened amorphous carbon layer may have a thickness of 0.01 ⁇ m to 0.5 ⁇ m.
  • the negative electrode active material of the present invention may have a sphere having an average particle diameter (D 50 ) of 5 ⁇ m to 22 ⁇ m, and an aspect ratio (length of long axis / length of short axis) may be 1 to 1.5.
  • the surface of the amorphous carbon layer surrounding the core 11 is roughened 15, thereby generating an anchoring effect in which curved surfaces are caught between the active materials contacting each other. Therefore, the adhesive force can be improved even with less binder. Therefore, it is possible to solve the problem of increasing the resistance due to the use of excess binder while the high loading of the negative electrode can be realized.
  • the specific surface area of the negative electrode active material is increased due to the roughened shell surface, the lithium ion is easily introduced and exited, thereby achieving high output of the battery.
  • the surface roughness Ra of the roughened amorphous carbon layer may be 0.01 ⁇ m to 5 ⁇ m. If the surface roughness of the amorphous carbon layer is less than 0.01 ⁇ m, the effect of improving adhesion is insignificant. If the thickness is greater than 5 ⁇ m, the thickness of the shell may become thinner, which may cause the core to be destroyed by the electrolyte.
  • the roughened amorphous carbon layer may include a first roughness surface having a surface roughness Ra of 1 ⁇ m to 5 ⁇ m and a second roughness surface having a surface roughness of 0.01 ⁇ m to 1 ⁇ m on the surface of the first roughness surface. .
  • the surface roughness is the sum of the total area of the top and bottom of the center line of the measurement section (reference length), and the measured value divided by the length of the measurement section (arithmetic mean roughness).
  • the first roughness surface having a larger roughness has an effect of increasing the loading rate of the active material while using fewer binders due to the anchoring effect of the surfaces contacted between the active materials, and having a smaller roughness on the first roughness surface.
  • the second roughness surface has the effect of widening the surface area of the negative electrode active material. Therefore, by using the negative electrode active material of the present invention including both the first roughness surface and the second roughness surface, it is possible to manufacture a negative electrode having high loading while having high loading, and showing excellent output.
  • the roughened amorphous carbon layer may have a specific surface area 1.5 to 2.0 times improved compared to the specific surface area of the amorphous carbon layer before roughening. If the specific surface area of the roughened amorphous carbon layer has a specific surface area increase rate of less than 1.5 times that of the amorphous carbon layer before roughening, the expected anchoring effect does not appear much, and thus the adhesion improvement range is insignificant, and more than 2.0 times. In the case of having a specific surface area increase rate of, the specific surface area becomes so large that the initial efficiency decreases and the capacity decreases.
  • It provides a method for producing a negative electrode active material comprising a; step (step 2) to roughen the surface of the amorphous carbon layer of step 1 by mechanical processing.
  • step 1 is a step of forming an amorphous carbon layer 13 on the core surface made of natural graphite (a).
  • Step 1 is more advantageous in the subsequent mechanical processing is performed by a method of coating the amorphous carbon on the surface of the natural graphite by mixing the solid amorphous carbon with natural graphite.
  • the solid phase pitch and the natural graphite can be performed by rotating and coating together in a drum mixer.
  • a conventional production method may be used through drying and heat treatment.
  • the natural graphite may have a spherical particle having an average particle diameter (D 50 ) of 1 ⁇ m to 20 ⁇ m, and an aspect ratio (length of major axis / length of minor axis) may be 1 to 1.5. As shown in FIG. 6, the natural graphite may be rolled into a spherical shape using a semicircular spherical cutter of a spheronization equipment, and may be shaved into a spherical shape.
  • the amorphous carbon layer may have a thickness of 0.01 ⁇ m to 5 ⁇ m, and the precursor of the amorphous carbon layer is at least one selected from coal pitch, petroleum pitch, polyvinyl chloride, mesophase pitch, tar and low molecular weight heavy oil.
  • Soft carbon raw materials Polyvinyl alcohol resin, furfuryl alcohol resin, triton, citric acid, stearic acid, sucrose, polyvinylidene fluoride, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, polyvinylpi Lollidon, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), polyacrylic acid, polyacrylic sodium, polyacrylonitrile, glucose, gelatin, sugars, phenol resins, naphthalene resins, polyamide resins, furan resins, polyis At least one hard carbon raw material selected from a mid resin, a cellulose resin, a styrene resin, an epoxy resin and a vinyl chloride resin; Or a combination thereof, and in particular, the amorphous carbon layer prepared using a phenol resin, naphthalene resin is preferred because it is easy to roughen and further maximize the anchoring effect.
  • the solvent mixed with the amorphous precursor is water, N-methylpyrrolidone, dimethylformamide, toluene, ethylene, dimethylacetamide, acetone, methyl ethyl ketone, hexane, tetrahydrofuran, decane, ethanol, methanol , Isopropanol, ethyl acetate or a combination thereof.
  • the amorphous carbon layer may be included in 2 to 5% by weight based on the entire negative active material. If the amorphous carbon layer is included in less than 2% by weight based on the entire negative electrode active material, the amorphous carbon layer is too thin so that the core of natural graphite is destroyed by the electrolyte or roughened to natural graphite, If it is included in more than 5% by weight may be a problem that is difficult to access the lithium ion.
  • step 2 is a step of roughening the surface of the amorphous carbon layer of step 1 by mechanical processing (b).
  • step 2 the surface of the amorphous carbon layer 13 surrounding the surface of the core 11 manufactured in step 1 is mechanically processed to roughen the surface of the negative electrode active material (15) to form irregularities, and thus the surface is roughened.
  • the negative electrode active material may have improved adhesion even with less binder due to the anchoring effect of the curved surface between the active materials in contact with each other, thereby increasing the specific surface area.
  • the mechanical processing of step 2 may be performed through the spheronization equipment shown in FIG. 6 used in step 1.
  • the original spheronization equipment may be used to spheronize a specific material using a semicircular spherical cutter, but in the present invention, instead of the spherical cutter as shown in FIG. It is possible to produce a curved shape with irregularities without cutting the surface of the amorphous carbon layer by using a barbed roughening cutter.
  • the mechanical processing of step 2 is not necessarily performed through the spheronization equipment, and a mechanical processing method capable of roughening the surface of the amorphous carbon layer may be appropriately selected and used.
  • the large first surface roughening cutter is used to make the round graphite into a large bumpy shape (b-1), and the second surface roughing cutter with a small area makes the bumpy shape small. (b-2)
  • the anchoring effect can be shown.
  • the equipment is operated at 500 rpm using a first roughening cutter having a diameter of 10 ⁇ m to form a first roughness surface, and then the equipment is operated at 200 rpm using a second roughening cutter having a diameter of 2 ⁇ m. Can be operated to form a second roughness surface.
  • the amorphous carbon layer may be mechanically processed to have a surface roughness Ra of 0.01 ⁇ m to 5 ⁇ m. If the surface roughness of the amorphous carbon layer is less than 0.01 ⁇ m, the effect of improving the adhesion is insignificant. If the surface roughness is more than 5 ⁇ m, natural graphite may be destroyed by the electrolyte.
  • the amorphous carbon layer may include a first roughness surface having a surface roughness Ra of 1 ⁇ m to 5 ⁇ m and a second roughness surface having a surface roughness of 0.01 ⁇ m to 1 ⁇ m on the surface of the amorphous carbon layer. It can be mechanically processed to have
  • the first roughness surface having a larger roughness has an effect of increasing the loading rate while using fewer binders due to the anchoring effect of the surfaces contacted between the active materials, and the second roughness having a smaller roughness on the first roughness surface.
  • Roughness surface has the effect of widening the surface area of the negative electrode active material. Therefore, by using the negative electrode active material of the present invention including both the first roughness surface and the second roughness surface, it is possible to manufacture a negative electrode having high loading while having high loading, and showing excellent output.
  • the roughened amorphous carbon layer may have a specific surface area 1.5 to 2.0 times improved compared to the specific surface area of the amorphous carbon layer before roughening. If the specific surface area of the roughened amorphous carbon layer has a specific surface area increase rate of less than 1.5 times that of the amorphous carbon layer before roughening, the expected anchoring effect does not appear much, and thus the adhesion improvement range is insignificant, and more than 2.0 times. In the case of having a specific surface area increase rate of, the specific surface area becomes so large that the initial efficiency decreases and the capacity decreases.
  • It provides a negative electrode comprising a; negative electrode mixture layer comprising the negative electrode active material formed on the current collector.
  • the negative electrode may be prepared by applying a slurry prepared by mixing the negative electrode mixture including the negative electrode active material of the present invention to an organic solvent on a negative electrode current collector, followed by drying and rolling.
  • at least one of the negative electrode mixture and the positive electrode mixture may include a binder, and in particular, it is preferable to use polyvinylidene fluoride (PVDF) as a binder.
  • PVDF polyvinylidene fluoride
  • the anchoring effect is expressed between the particles, so that the adhesive strength of the electrode is increased at the same binder content, and thus secondary loading due to the use of an excessive amount of binder can be achieved.
  • the problem that the resistance of a battery increases can be solved.
  • the specific surface area is increased due to the roughened surface, the entrance and exit of lithium ions is facilitated, and thus there is an effect of implementing a high output secondary battery.
  • a secondary battery including the anode, a cathode coated with a cathode mixture including a cathode active material, and an electrolyte solution.
  • the positive electrode active material of the secondary battery is not particularly limited, specifically, a lithium transition metal oxide may be used.
  • the lithium transition metal oxide include Li.Co-based composite oxides such as LiCoO 2 , Li.Ni.Co.Mn-based composite oxides such as LiNi x Co y Mn z O 2 , and Li.sub.2 such as LiNiO 2 .
  • Ni-based composite oxide may be mentioned, such as LiMn 2 O 4 of the Li-Mn composite oxide such, may be mixed alone or a plurality of them.
  • the positive electrode mixture and the negative electrode mixture may include a conductive material, and are not particularly limited as long as they have conductivity without causing chemical change in the battery.
  • a conductive material for example, graphite; Carbon blacks such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black and summer black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride powder, aluminum powder and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.
  • the positive electrode or the negative electrode may have a form in which the positive electrode mixture or the negative electrode mixture is coated on a current collector.
  • the current collector is not particularly limited as long as it is conductive without causing chemical change in the battery.
  • the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel Surface treated with carbon, nickel, titanium, silver, or the like can be used.
  • the said electrolyte solution is a lithium salt containing electrolyte solution
  • a non-aqueous organic solvent, an organic solid electrolyte, an inorganic solid electrolyte, etc. are used, it is not limited to these.
  • a battery module including the secondary battery as a unit cell and a battery pack including the same are provided.
  • the battery module or battery pack includes a secondary battery having low resistance, high capacity, and high output characteristics, such as a power tool, an electric vehicle (EV), a hybrid electric vehicle (HEV), and Electric vehicles, including plug-in hybrid electric vehicles (PHEVs), or any one or more of the power storage system can be used as a power source for the device.
  • a power tool such as a power tool, an electric vehicle (EV), a hybrid electric vehicle (HEV), and Electric vehicles, including plug-in hybrid electric vehicles (PHEVs), or any one or more of the power storage system can be used as a power source for the device.
  • EV electric vehicle
  • HEV hybrid electric vehicle
  • PHEVs plug-in hybrid electric vehicles
  • Step 1 1000 g of natural graphite (product name: SG16) having an average particle diameter (D 50 ) of 16 ⁇ m and 100 g of coal tar pitch, a precursor of an amorphous carbon layer, were mixed in a drum type mixer for 2 hours. Thereafter, heat treatment was performed at 1150 ° C. for 600 minutes to prepare natural graphite coated with an amorphous carbon layer (specific surface area of 3.3 m 2 / g).
  • Natural graphite coated with the amorphous carbon layer prepared above was added to a spheronization equipment (equipment name: AMD3), and spheronized at a process condition (time, speed, etc.) at 1000 rpm for 2 hours using a spherical cutter.
  • Step 2 The spherical amorphous carbon layer-coated natural graphite was put into a spheronization apparatus replaced with a roughening cutter having a diameter of 10 ⁇ m in the form of a needle, and processed at a speed of 500 rpm to obtain a surface roughness of 7 ⁇ m.
  • the branches formed the first roughness plane.
  • the second active material was processed at 200 rpm to form a second roughness surface having a surface roughness of 3 ⁇ m, and the anode active material including an amorphous carbon layer whose surface was roughened (non- Surface area of 4.1 m 2 / g).
  • Step 3 The negative electrode mixture was prepared by mixing 98 g of the natural graphite coated with the roughened amorphous carbon layer, 1 g of PVDF as a binder, and 1 g of carbon black as a conductive material. The negative electrode mixture was coated on a copper current collector, dried at 120 ° C. in a vacuum oven, and rolled to prepare a negative electrode.
  • Step 4 LiNi 0 with the negative electrode . 6 Mn 0 . 2 Co 0 .
  • a lithium secondary battery was prepared by interposing a porous polyethylene separator between the positive electrodes using 2 O 2 as a positive electrode active material and injecting a lithium electrolyte.
  • An anode active material comprising a core (natural graphite) coated with an amorphous carbon layer (surface roughness 0) in the same manner as in Example 1, except that Step 2 in Example 1 was not performed, and the same.
  • a negative electrode and a secondary battery having the same were prepared.
  • Example 1 The negative electrode active materials prepared in Example 1 and Comparative Example 1 were observed with a scanning electron microscope (SEM), and the results are shown in FIG. 3.
  • the surface-negative anode active material according to the present invention has a roughness plane having a heterogeneous size. Furthermore, it can be predicted that the anchoring effect can be realized due to the relatively large roughness plane, and that a large surface area can be exhibited due to the relatively small roughness plane.
  • the adhesion of the negative electrode of Example 1 using the roughened negative electrode active material was about 75 gf / 10mm, whereas the adhesion of the negative electrode of Comparative Example 1 using the non-roughened negative electrode active material was about 30 gf. / 10mm, it can be seen that the adhesion of the negative electrode of Example 1 of the present invention is about 2.5 times as excellent.
  • the lithium secondary batteries prepared in Example 1 and Comparative Example 1 were measured for continuous discharge characteristics (discharge output value: 160 mW) under SOC 50% at room temperature, and the results are shown in FIG. 5.
  • Example 1 including the roughened negative electrode active material having a voltage characteristic over time is superior to the secondary battery of Comparative Example 1 that is not roughened in all time sections.
  • the roughened negative electrode active material has a wider surface area than the non-roughened negative electrode active material, and thus it is easy to access lithium ions, thereby providing a secondary battery having a higher output.

Abstract

The present invention relates to a cathode active material and a preparation method therefor and, specifically, to a cathode active material comprising: a core comprising natural graphite; and a shell encompassing the core and comprising a roughened amorphous carbon layer. According to the present invention, the cathode active material is roughened, and thus adhesive strength can be improved even while using a small amount of a binder because of the anchoring effect in which curved surfaces are caught between active materials coming in contact with each other. Therefore, the problem of an increase in resistance caused by the use of an excessive amount of a binder can be solved while implementing high loading of a cathode. In addition, high output of a battery can be implemented by facilitating the entering and exiting of lithium ions since the specific surface area increases due to a roughened surface.

Description

음극 활물질 및 이의 제조방법Anode active material and method for preparing same
관련 출원(들)과의 상호 인용Cross Citation with Related Application (s)
본 출원은 2015년 3월 23일자 한국 특허 출원 제10-2015-0039933호 및 2016년 3월 21일자 한국 특허출원 제10-2016-0033216호에 기초한 우선권 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. 10-2015-0039933 filed on March 23, 2015 and Korean Patent Application No. 10-2016-0033216 filed on March 21, 2016. All content disclosed in is included as part of this specification.
기술분야Technical Field
본 발명은 음극 활물질 및 이의 제조방법에 관한 것이다. The present invention relates to a negative electrode active material and a method of manufacturing the same.
화석연료 사용의 급격한 증가로 인하여 대체 에너지나 청정에너지의 사용에 대한 요구가 증가하고 있으며, 그 일환으로 가장 활발하게 연구되고 있는 분야가 전기화학 반응을 이용한 발전, 축전 분야이다.Due to the rapid increase in the use of fossil fuels, the demand for the use of alternative energy or clean energy is increasing, and the most actively researched fields are power generation and storage using electrochemical reactions.
현재 이러한 전기화학적 에너지를 이용하는 전기화학 소자의 대표적인 예로 이차전지를 들 수 있으며, 점점 더 그 사용 영역이 확대되고 있는 추세이다. 최근에는 휴대용 컴퓨터, 휴대용 전화기, 카메라 등의 휴대용 기기에 대한 기술 개발과 수요가 증가함에 따라 에너지원으로서 이차전지의 수요가 급격히 증가하고 있고, 그러한 이차전지 중 높은 에너지 밀도와 작동 전위를 나타내고 사이클 수명이 길며 자기방전율이 낮은 리튬 이차전지에 대해 많은 연구가 행해져 왔고, 또한 상용화되어 널리 사용되고 있다.A representative example of an electrochemical device using such electrochemical energy is a secondary battery, and its use area is gradually increasing. Recently, as the development and demand for portable devices such as portable computers, portable telephones, cameras, and the like, the demand for secondary batteries is rapidly increasing, and these secondary batteries exhibit high energy density and operating potential, and have a cycle life. Many studies have been conducted on this long, low self-discharge rate lithium battery and are commercially available and widely used.
또한, 환경 문제에 대한 관심이 커짐에 따라 대기오염의 주요 원인의 하나인 가솔린 차량, 디젤 차량 등 화석연료를 사용하는 차량을 대체할 수 있는 전기자동차, 하이브리드 전기자동차 등에 대한 연구가 많이 진행되고 있다. 이러한 전기자동차, 하이브리드 전기자동차 등의 동력원으로는 주로 니켈 수소금속 이차전지가 사용되고 있지만, 높은 에너지 밀도와 방전 전압의 리튬 이차전지를 사용하는 연구가 활발히 진행되고 있으며, 일부 상용화 단계에 있다.In addition, as interest in environmental issues grows, researches on electric vehicles and hybrid electric vehicles, which can replace vehicles using fossil fuel, such as gasoline and diesel vehicles, which are one of the main causes of air pollution, are being conducted. . As a power source of such electric vehicles and hybrid electric vehicles, nickel-metal hydride secondary batteries are mainly used, but researches using lithium secondary batteries with high energy density and discharge voltage have been actively conducted and some commercialization stages are in progress.
종래 전형적인 리튬 이차전지는 음극 활물질로 흑연을 사용하며, 양극의 리튬 이온이 음극으로 삽입되고 탈리되는 과정을 반복하면서 충전과 방전이 진행된다. 전극 활물질의 종류에 따라 전지의 이론 용량은 차이가 있으나, 대체로 사이클이 진행됨에 따라 충전 및 방전 용량이 저하되는 문제점이 발생하게 된다.Conventionally, a typical lithium secondary battery uses graphite as a negative electrode active material, and charging and discharging are performed while repeating a process in which lithium ions of a positive electrode are inserted into and detached from a negative electrode. The theoretical capacity of the battery is different depending on the type of the electrode active material, but as the cycle progresses, the charge and discharge capacity is generally lowered.
한편, 특허문헌 1에는 음극 활물질과 관련된 종래 기술로서 리튬 이차 전지용 음극과 이의 제조 방법, 및 이를 포함하는 리튬 이차 전지를 제공한다. 구체적으로, 집전체 및 상기 집전체 위에 형성되는 음극 활물질 층을 포함하고, 상기 음극 활물질 층은 탄소계 음극 활물질 및 폴리아크릴산 바인더를 포함하며, 상기 탄소계 음극 활물질에 대한 상기 폴리아크릴산 바인더의 중량비는 0.01 내지 0.4인 리튬 이차 전지용 음극과 이의 제조 방법, 및 이를 포함하는 리튬 이차 전지를 제공한다. On the other hand, Patent Document 1 provides a negative electrode for a lithium secondary battery, a method for producing the same, and a lithium secondary battery including the same as a related art related to a negative electrode active material. Specifically, a current collector and a negative electrode active material layer formed on the current collector, the negative electrode active material layer includes a carbon-based negative electrode active material and a polyacrylic acid binder, the weight ratio of the polyacrylic acid binder to the carbon-based negative electrode active material It provides a negative electrode for a lithium secondary battery of 0.01 to 0.4 and a method of manufacturing the same, and a lithium secondary battery comprising the same.
그러나 상기와 같은 종래 음극은 바인더를 과량으로 사용하게 되어 전극 저항이 증가하는 문제점이 있을 수 있다. However, the conventional negative electrode as described above may have a problem that the electrode resistance is increased by using an excessive amount of the binder.
따라서, 전극의 제조 시 접착력을 높이면서도 저항을 줄일 수 있는 음극 활물질의 개발이 요구된다. Therefore, the development of a negative electrode active material that can reduce the resistance while increasing the adhesion in the manufacture of the electrode is required.
선행기술문헌Prior art literature
대한민국 공개특허공보 제10-2014-0093877호Republic of Korea Patent Publication No. 10-2014-0093877
본 발명의 해결하고자 하는 제1 기술적 과제는 바인더는 적게 사용하면서, 접착력은 향상된 전극을 제조할 수 있는 음극 활물질을 제공하는 것이다. The first technical problem to be solved of the present invention is to provide a negative electrode active material that can produce an electrode with improved adhesion while using less binder.
본 발명의 해결하고자 하는 제2 기술적 과제는 상기 음극 활물질의 제조방법을 제공하는 것이다.The second technical problem to be solved of the present invention is to provide a method of manufacturing the negative electrode active material.
또한, 본 발명의 해결하고자 하는 제3 기술적 과제는 상기 음극 활물질을 포함하는 음극을 제공하는 것이다.In addition, a third technical problem to be solved of the present invention is to provide a negative electrode including the negative electrode active material.
또한, 본 발명의 해결하고자 하는 제4 기술적 과제는 상기 음극을 구비한 이차전지와, 이를 구비한 전지모듈 및 전지팩을 제공하는 것이다. In addition, a fourth technical problem to be solved of the present invention is to provide a secondary battery having the negative electrode, a battery module and a battery pack having the same.
상기 과제를 해결하기 위하여, 본 발명의 일 실시예에서는 In order to solve the above problems, in one embodiment of the present invention
천연흑연을 포함하는 코어; 및 상기 코어 표면에 형성되는, 조면화(粗面, roughened)된 비정질 탄소층을 포함하는 쉘;을 포함함으로써, 표면이 접착력이 향상된 음극 활물질을 제공한다. A core comprising natural graphite; And a shell formed on the surface of the core, the shell including a roughened amorphous carbon layer, thereby providing an anode active material having improved adhesion to the surface.
또한, 본 발명은 천연흑연의 표면에 비정질 탄소층을 형성하는 단계(단계 1); 및 상기 단계 1의 비정질 탄소층의 표면을 기계적 가공하여 조면화하는 단계(단계 2);를 포함하는 음극 활물질의 제조방법을 제공한다.In addition, the present invention comprises the steps of forming an amorphous carbon layer on the surface of natural graphite (step 1); And roughening by roughening the surface of the amorphous carbon layer of step 1 (step 2).
또한, 본 발명은 집전체; 및 상기 집전체 상에 형성된 상기 음극 활물질을 포함하는 음극 합제층;을 포함하는 음극을 제공한다.In addition, the present invention is a current collector; And a negative electrode mixture layer including the negative electrode active material formed on the current collector.
또한, 본 발명은 상기 음극과, 양극 활물질을 포함하는 양극 합제가 도포되어 있는 양극, 및 전해액을 포함하는 이차전지, 전지모듈 및 전지팩을 제공한다.The present invention also provides a secondary battery, a battery module, and a battery pack including the anode, a cathode coated with a cathode mixture including a cathode active material, and an electrolyte.
본 발명에 따른 음극 활물질은 표면이 조면화되어, 서로 맞닿은 활물질 간에 굴곡진 표면에서 걸리는 앵커링 효과(anchoring effect)로 인해 바인더를 적게 사용하고도 접착력 향상 효과를 구현할 수 있다. 따라서, 음극의 고로딩화를 구현할 수 있으면서도 소량의 바인더 사용으로 인해, 저항 증가를 방지할 수 있다. The surface of the negative electrode active material according to the present invention is roughened, it is possible to implement the adhesive force improvement effect even using less binder due to the anchoring effect (anchoring effect) applied on the curved surface between the active material in contact with each other. Therefore, while the high loading of the negative electrode can be realized, the use of a small amount of binder can prevent the increase in resistance.
더욱이, 본 발명에 따른 음극 활물질은 조면화된 표면에 의하여, 비표면적이 증가되어 리튬 이온의 출입이 용이해지므로, 전지의 고출력을 구현할 수 있다. In addition, the negative electrode active material according to the present invention has a specific surface area, thereby increasing the access of lithium ions due to the roughened surface, thereby achieving high output of the battery.
도 1은 본 발명의 일 실시예에 따른 음극활물질의 형상을 개략적으로 나타낸 모식도이다.1 is a schematic diagram schematically showing the shape of the negative electrode active material according to an embodiment of the present invention.
도 2는 본 발명의 일 실시예에 따른 음극 활물질 제조 방법을 개략적으로 나타낸 모식도이다.Figure 2 is a schematic diagram schematically showing a method for producing a negative electrode active material according to an embodiment of the present invention.
도 3은 (a) 실시예 1 및 (b) 비교예 1에서 제조된 음극 활물질을 주사 전자 현미경으로 관찰한 사진이다. Figure 3 is a photograph of the negative electrode active material prepared in (a) Example 1 and (b) Comparative Example 1 observed with a scanning electron microscope.
도 4는 실시예 1 및 비교예 1에서 제조된 음극의 접착력을 측정한 결과 그래프이다. Figure 4 is a graph of the results of measuring the adhesion of the negative electrode prepared in Example 1 and Comparative Example 1.
도 5는 실시예 1 및 비교예 1에서 제조된 이차전지의 방전 특성을 측정한 결과 그래프이다. 5 is a graph showing the results of measuring discharge characteristics of the secondary batteries manufactured in Example 1 and Comparative Example 1. FIG.
도 6은 본 발명의 일 실시예에 따른 구형화 장비를 개략적으로 나타낸 모식도이다.6 is a schematic diagram schematically showing a spheronization equipment according to an embodiment of the present invention.
도면부호의 설명Explanation of References
11: 코어11: core
13: 비정질 탄소층13: amorphous carbon layer
15: 표면이 조면화된 비정질 탄소층15: A roughened surface of the amorphous carbon layer
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.
본 명세서에서 사용되는 용어는 단지 예시적인 실시예들을 설명하기 위해 사용된 것으로, 본 발명을 한정하려는 의도는 아니다. 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한, 복수의 표현을 포함한다. The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.
본 명세서에서, “포함하다”, “구비하다” 또는 “가지다” 등의 용어는 실시된 특징, 숫자, 단계, 구성 요소 또는 이들을 조합한 것이 존재함을 지정하려는 것이지, 하나 또는 그 이상의 다른 특징들이나 숫자, 단계, 구성 요소, 또는 이들을 조합한 것들의 존재 또는 부가 가능성을 미리 배제하지 않는 것으로 이해되어야 한다.In this specification, the terms “comprise,” “comprise,” or “have” are intended to indicate that there is a feature, number, step, component, or combination thereof, that is, one or more other features, It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.
종래에 이차전지의 흑연계 음극재로서 사용되고 있는 물질은 대부분이 표면이 비정질 탄소로 코팅된 구형화 천연흑연이었다. 그러나 음극의 고로딩화가 진행될수록 접착력이 저하되는 문제가 발생하였고, 이를 해결하기 위해 바인더의 함량을 증가시키면 저항이 증가하는 부작용이 발생하였다. Conventionally, the material used as the graphite negative electrode material of a secondary battery was spherical natural graphite in which the surface was mostly coated with amorphous carbon. However, as the loading of the negative electrode progressed, the adhesive force was deteriorated. In order to solve this problem, increasing the content of the binder caused a side effect of increasing the resistance.
이에, 본 발명에서는 음극의 고로딩화, 우수한 접착력 및 고출력을 동시에 구현할 수 있는 음극 활물질을 제공하고자 한다. Thus, the present invention is to provide a negative electrode active material that can implement high loading of the negative electrode, excellent adhesion and high power at the same time.
구체적으로, 본 발명의 일 실시예에서는Specifically, in one embodiment of the present invention
천연흑연을 포함하는 코어; 및 A core comprising natural graphite; And
상기 코어 표면에 형성된, 조면화(粗面, roughened)된 비정질 탄소층을 포함하는 쉘;을 포함하는 음극 활물질을 제공한다.It provides a negative electrode active material comprising a; a shell including a roughened amorphous carbon layer formed on the surface of the core.
이하, 본 발명에 따른 음극 활물질을 상세히 설명한다. Hereinafter, the negative electrode active material according to the present invention will be described in detail.
본 발명의 음극활물질에 있어서, 상기 코어는 평균입경(D50)이 1 ㎛ 내지 20 ㎛인 구형일 수 있으며, 종횡비(aspect ratio, 장축의 길이/단축의 길이)는 1 내지 1.5일 수 있다(이때, 상기 평균입경(D50)은 입도 분포에서 누적 부피가 50 부피%에 해당되는 입자의 지름을 의미한다).In the negative electrode active material of the present invention, the core may have a spherical shape having an average particle diameter (D 50 ) of 1 μm to 20 μm, and an aspect ratio (length of long axis / length of short axis) may be 1 to 1.5 ( In this case, the average particle diameter (D 50 ) means the diameter of the particles corresponding to the cumulative volume 50% by volume in the particle size distribution).
상기 코어는 천연흑연을 포함할 수 있다. 통상 이차 전지의 음극 활물질로는 결정질 흑연 재료가 주로 사용되며, 상기 천연흑연은 결정질 흑연에 해당한다. 상기 코어에 포함되는 천연흑연은 인편상의 천연흑연을 구형으로 조립화(造粒化)시킨 구형의 형태일 수 있다. The core may comprise natural graphite. Usually, a crystalline graphite material is mainly used as a negative electrode active material of a secondary battery, and the natural graphite corresponds to crystalline graphite. The natural graphite included in the core may be in the form of a sphere in which granular natural graphite is granulated into a sphere.
이때, 음극 활물질로서 천연흑연을 사용하는 경우 고율 충방전 특성 및 사이클 수명 특성이 보다 저조하다. 따라서, 적절한 양의 비정질 탄소층으로 코팅하여 천연흑연의 표면을 감싸줌으로써, 전해질에 의한 파괴를 방지하고 비가역 반응을 감소시킬 수 있다. In this case, when natural graphite is used as the negative electrode active material, high rate charge / discharge characteristics and cycle life characteristics are lower. Thus, by coating with an appropriate amount of amorphous carbon layer to cover the surface of natural graphite, it is possible to prevent destruction by the electrolyte and to reduce irreversible reaction.
상기 쉘을 이루는 상기 비정질 탄소층은 석탄계 핏치, 석유계 핏치, 폴리비닐클로라이드, 메조페이스 핏치, 타르 및 저분자량 중질유로부터 선택되는 적어도 하나의 소프트 카본 원료; 폴리비닐알코올 수지, 퍼푸릴 알코올(furfuryl alcohol) 수지, 트리톤(triton), 구연산, 스테아르산(stearic acid), 수크로오스, 폴리불화비닐리덴, 카르복시메틸셀룰로오스, 히드록시프로필셀룰로오스, 재생셀룰로오스, 폴리비닐피롤리돈, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 모노머(EPDM), 폴리아크릴산, 폴리아크릴나트륨, 폴리아크릴로니트릴, 글루코오스, 젤라틴, 당류, 페놀 수지, 나프탈렌 수지, 폴리아미드 수지, 퓨란 수지, 폴리이미드 수지, 셀룰로오스 수지, 스티렌 수지, 에폭시 수지 및 염화비닐 수지로부터 선택되는 적어도 하나의 하드 카본 원료; 또는 이들을 조합한 전구체를 이용하여 형성할 수 있다. 특히 페놀 수지, 나프탈렌 수지를 사용하여 제조된 비정질 탄소층은 조면화가 용이하고 앵커링 효과를 더욱 극대화할 수 있어 바람직하다. The amorphous carbon layer constituting the shell may include at least one soft carbon raw material selected from coal-based pitch, petroleum-based pitch, polyvinyl chloride, mesophase pitch, tar, and low molecular weight heavy oil; Polyvinyl alcohol resin, furfuryl alcohol resin, triton, citric acid, stearic acid, sucrose, polyvinylidene fluoride, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, polyvinylpi Lollidon, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), polyacrylic acid, polyacrylic sodium, polyacrylonitrile, glucose, gelatin, sugars, phenol resins, naphthalene resins, polyamide resins, furan resins, polyis At least one hard carbon raw material selected from a mid resin, a cellulose resin, a styrene resin, an epoxy resin and a vinyl chloride resin; Or it can form using the precursor which combined these. In particular, an amorphous carbon layer prepared using a phenol resin or a naphthalene resin is preferred because it is easy to roughen and further maximize the anchoring effect.
상기 비정질 탄소층은 음극 활물질 전체 중량에 대하여 약 2 내지 5 중량%로 포함될 수 있다. 만약, 상기 비정질 탄소층이 음극 활물질 전체에 대하여 2 중량% 미만으로 포함되는 경우에는 비정질 탄소층이 너무 얇아 코어인 천연흑연이 전해질에 의해 파괴되거나, 코어까지 조면화되는 문제점이 발생할 수 있고, 5 중량% 초과로 포함되는 경우에는 쉘의 두께 증가로 리튬 이온의 출입이 어려운 문제점이 발생할 수 있다. The amorphous carbon layer may be included in about 2 to 5% by weight based on the total weight of the negative electrode active material. If the amorphous carbon layer is included in less than 2% by weight based on the entire negative active material, the amorphous carbon layer is too thin so that the natural graphite as a core may be destroyed by the electrolyte, or roughened to the core, 5 In the case where the content is included in an amount of more than% by weight, it is difficult to access lithium ions due to an increase in thickness of the shell.
상기 비정질 탄소층의 중량은 열중량분석기(TGA) 측정방법으로 측정할 수 있다. The weight of the amorphous carbon layer may be measured by a thermogravimetric analyzer (TGA) measuring method.
예를 들어, TGA를 통해서 온도를 4 ℃/min으로 상승시키면서 중량 손실(mass loss)을 측정하면, 저결정성 코팅층과 결정성 코어의 중량 손실 온도 범위가 다르기 때문에 중량비를 통해서 코팅 양을 측정할 수 있다.For example, if the mass loss is measured while the temperature is increased to 4 ° C./min through the TGA, the weight loss temperature range of the low crystalline coating layer and the crystalline core is different, and thus the coating amount may be measured by the weight ratio. Can be.
본 발명의 음극활물질에 있어서, 상기 조면화된 비정질 탄소층을 포함하는 쉘은 0.01 ㎛ 내지 0.5 ㎛의 두께를 가질 수 있다.In the negative electrode active material of the present invention, the shell including the roughened amorphous carbon layer may have a thickness of 0.01 μm to 0.5 μm.
또한, 본 발명의 음극 활물질은 평균입경(D50) 5 ㎛ 내지 22 ㎛의 구형일 수 있으며, 종횡비(aspect ratio, 장축의 길이/단축의 길이)는 1 내지 1.5일 수 있다. In addition, the negative electrode active material of the present invention may have a sphere having an average particle diameter (D 50 ) of 5 μm to 22 μm, and an aspect ratio (length of long axis / length of short axis) may be 1 to 1.5.
도 1에 도시한 바와 같이, 본 발명에 따른 음극 활물질은 코어(11)를 둘러싼 비정질 탄소층 표면이 조면화되어(15), 서로 맞닿은 활물질 간에 굴곡진 표면이 걸리는 앵커링 효과(anchoring effect)이 발생하기 때문에, 바인더를 적게 사용하고도 접착력이 향상될 수 있다. 따라서, 음극의 고로딩화를 구현할 수 있으면서도 과량의 바인더 사용으로 인해 저항이 증가하는 문제점을 해결할 수 있다. 또한, 조면화된 쉘 표면으로 인해 음극활물질의 비표면적이 증가되므로, 리튬 이온의 출입이 용이해져 전지의 고출력을 구현할 수 있는 효과가 있다. As shown in FIG. 1, in the anode active material according to the present invention, the surface of the amorphous carbon layer surrounding the core 11 is roughened 15, thereby generating an anchoring effect in which curved surfaces are caught between the active materials contacting each other. Therefore, the adhesive force can be improved even with less binder. Therefore, it is possible to solve the problem of increasing the resistance due to the use of excess binder while the high loading of the negative electrode can be realized. In addition, since the specific surface area of the negative electrode active material is increased due to the roughened shell surface, the lithium ion is easily introduced and exited, thereby achieving high output of the battery.
이때, 상기 조면화된 비정질 탄소층의 표면 조도(Ra)는 0.01 ㎛ 내지 5 ㎛일 수 있다. 만약, 상기 비정질 탄소층의 표면 조도가 0.01 ㎛ 미만인 경우에는 접착력 향상의 효과가 미미한 문제점이 있고, 5 ㎛ 초과인 경우에는 쉘의 일부 두께가 얇아져 코어가 전해질에 의해 파괴되는 문제점이 발생할 수 있다. In this case, the surface roughness Ra of the roughened amorphous carbon layer may be 0.01 μm to 5 μm. If the surface roughness of the amorphous carbon layer is less than 0.01 μm, the effect of improving adhesion is insignificant. If the thickness is greater than 5 μm, the thickness of the shell may become thinner, which may cause the core to be destroyed by the electrolyte.
구체적으로, 상기 조면화된 비정질 탄소층은 표면 조도(Ra) 1 ㎛ 내지 5 ㎛을 갖는 제1 조도면 및 상기 제1 조도면 표면에 표면 조도 0.01 ㎛ 내지 1 ㎛를 갖는 제2 조도면을 포함할 수 있다. Specifically, the roughened amorphous carbon layer may include a first roughness surface having a surface roughness Ra of 1 μm to 5 μm and a second roughness surface having a surface roughness of 0.01 μm to 1 μm on the surface of the first roughness surface. .
상기 표면 조도는 측정구간(기준길이)의 중심선에서 위쪽과 아래쪽의 전체 면적의 합을 구하고, 그 측정 값을 측정 구간의 길이로 나눈 값 (산술평균조도)이다. The surface roughness is the sum of the total area of the top and bottom of the center line of the measurement section (reference length), and the measured value divided by the length of the measurement section (arithmetic mean roughness).
보다 큰 크기의 조도를 갖는 제1 조도면은 활물질 간에 맞닿은 면끼리 서로 걸리는 앵커링 효과를 나타내어 바인더를 적게 사용하면서도 활물질의 로딩율을 높이는 효과가 있고, 상기 제1 조도면 상에 보다 작은 크기의 조도를 갖는 제2 조도면은 음극 활물질의 표면적을 넓게 하는 효과가 있다. 따라서, 제1 조도면 및 제2 조도면을 모두 포함하는 본 발명의 음극 활물질을 사용하면 고로딩이면서도 높은 접착력을 가지고, 우수한 출력을 나타내는 음극을 제조할 수 있다. The first roughness surface having a larger roughness has an effect of increasing the loading rate of the active material while using fewer binders due to the anchoring effect of the surfaces contacted between the active materials, and having a smaller roughness on the first roughness surface. The second roughness surface has the effect of widening the surface area of the negative electrode active material. Therefore, by using the negative electrode active material of the present invention including both the first roughness surface and the second roughness surface, it is possible to manufacture a negative electrode having high loading while having high loading, and showing excellent output.
한편, 상기 조면화된 비정질 탄소층은, 조면화되기 전의 비정질 탄소층의 비표면적에 비해 1.5 내지 2.0 배 향상된 비표면적을 가질 수 있다. 만약, 조면화된 비정질 탄소층의 비표면적이 조면화되기 전의 비정질 탄소층에 비해 1.5배 미만의 비표면적 증가율을 갖는 경우, 기대하는 앵커링 효과가 크게 나타나지 않아서 접착력 향상 폭이 미미하며, 2.0 배 초과의 비표면적 증가율을 갖는 경우 비표면적이 너무 커져서 초기효율의 감소 및 용량 저하가 발생한다. Meanwhile, the roughened amorphous carbon layer may have a specific surface area 1.5 to 2.0 times improved compared to the specific surface area of the amorphous carbon layer before roughening. If the specific surface area of the roughened amorphous carbon layer has a specific surface area increase rate of less than 1.5 times that of the amorphous carbon layer before roughening, the expected anchoring effect does not appear much, and thus the adhesion improvement range is insignificant, and more than 2.0 times. In the case of having a specific surface area increase rate of, the specific surface area becomes so large that the initial efficiency decreases and the capacity decreases.
또한, 본 발명의 일 실시예에서는 In addition, in one embodiment of the present invention
천연흑연의 표면에 비정질 탄소층을 형성하는 단계(단계 1); 및Forming an amorphous carbon layer on the surface of natural graphite (step 1); And
상기 단계 1의 비정질 탄소층의 표면을 기계적 가공하여 조면화하는 단계(단계 2);를 포함하는 음극 활물질의 제조방법을 제공한다. It provides a method for producing a negative electrode active material comprising a; step (step 2) to roughen the surface of the amorphous carbon layer of step 1 by mechanical processing.
이하, 본 발명에 따른 음극 활물질의 제조방법을 도 2를 참조하여 각 단계별로 상세히 설명한다. Hereinafter, a method of manufacturing an anode active material according to the present invention will be described in detail with respect to each step.
본 발명에 따른 음극 활물질의 제조방법에 있어서, 단계 1은 천연흑연으로 이루어진 코어 표면에 비정질 탄소층(13)을 형성하는 단계이다(a). In the method of manufacturing a negative electrode active material according to the present invention, step 1 is a step of forming an amorphous carbon layer 13 on the core surface made of natural graphite (a).
상기 단계 1은 고상의 비정질 탄소를 천연흑연과 함께 혼합함으로써, 천연흑연의 표면에 비정질 탄소를 코팅하는 방법으로 수행되는 것이 후속 공정인 기계적 가공을 하는데 있어 보다 유리하다. 구체적으로, 고상 피치(pitch)와 천연흑연을 드럼 믹서에서 함께 회전시켜 코팅하는 방법으로 수행할 수 있다. 다만, 상기 방법에 제한되지 않으며 천연흑연과 비정질 탄소 전구체 및 용매를 혼합한 후, 건조 및 열처리를 통해 제조하는 통상적인 제조방법을 사용할 수 있다. Step 1 is more advantageous in the subsequent mechanical processing is performed by a method of coating the amorphous carbon on the surface of the natural graphite by mixing the solid amorphous carbon with natural graphite. Specifically, the solid phase pitch and the natural graphite can be performed by rotating and coating together in a drum mixer. However, it is not limited to the above method, and after mixing natural graphite with an amorphous carbon precursor and a solvent, a conventional production method may be used through drying and heat treatment.
상기 천연흑연은 평균입경(D50) 1 ㎛ 내지 20 ㎛의 구형인 것을 사용할 수 있으며, 종횡비(aspect ratio, 장축의 길이/단축의 길이)는 1 내지 1.5일 수 있다. 도 6에 나타낸 바와 같이, 상기 천연흑연은 구형화 장비의 반원 형태의 구형화 커터를 사용하여 구형의 형태로 말려지고, 깎여 구형화된 것일 수 있다. The natural graphite may have a spherical particle having an average particle diameter (D 50 ) of 1 μm to 20 μm, and an aspect ratio (length of major axis / length of minor axis) may be 1 to 1.5. As shown in FIG. 6, the natural graphite may be rolled into a spherical shape using a semicircular spherical cutter of a spheronization equipment, and may be shaved into a spherical shape.
상기 비정질 탄소층은 0.01 ㎛ 내지 5 ㎛의 두께를 가질 수 있으며, 상기 비정질 탄소층의 전구체는 석탄계 핏치, 석유계 핏치, 폴리비닐클로라이드, 메조페이스 핏치, 타르 및 저분자량 중질유로부터 선택되는 적어도 하나의 소프트 카본 원료; 폴리비닐알코올 수지, 퍼푸릴 알코올(furfuryl alcohol) 수지, 트리톤(triton), 구연산, 스테아르산(stearic acid), 수크로오스, 폴리불화비닐리덴, 카르복시메틸셀룰로오스, 히드록시프로필셀룰로오스, 재생셀룰로오스, 폴리비닐피롤리돈, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 모노머(EPDM), 폴리아크릴산, 폴리아크릴나트륨, 폴리아크릴로니트릴, 글루코오스, 젤라틴, 당류, 페놀 수지, 나프탈렌 수지, 폴리아미드 수지, 퓨란 수지, 폴리이미드 수지, 셀룰로오스 수지, 스티렌 수지, 에폭시 수지 및 염화비닐 수지로부터 선택되는 적어도 하나의 하드 카본 원료; 또는 이들의 조합일 수 있으며, 특히 페놀 수지, 나프탈렌 수지를 사용하여 제조된 비정질 탄소층은 조면화가 용이하고 앵커링 효과를 더욱 극대화할 수 있어 바람직하다.The amorphous carbon layer may have a thickness of 0.01 μm to 5 μm, and the precursor of the amorphous carbon layer is at least one selected from coal pitch, petroleum pitch, polyvinyl chloride, mesophase pitch, tar and low molecular weight heavy oil. Soft carbon raw materials; Polyvinyl alcohol resin, furfuryl alcohol resin, triton, citric acid, stearic acid, sucrose, polyvinylidene fluoride, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, polyvinylpi Lollidon, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), polyacrylic acid, polyacrylic sodium, polyacrylonitrile, glucose, gelatin, sugars, phenol resins, naphthalene resins, polyamide resins, furan resins, polyis At least one hard carbon raw material selected from a mid resin, a cellulose resin, a styrene resin, an epoxy resin and a vinyl chloride resin; Or a combination thereof, and in particular, the amorphous carbon layer prepared using a phenol resin, naphthalene resin is preferred because it is easy to roughen and further maximize the anchoring effect.
이때, 상기 비정질 전구체와 함께 혼합하는 상기 용매는 물, N-메틸피롤리돈, 디메틸포름아미드, 톨루엔, 에틸렌, 디메틸아세트아미드, 아세톤, 메틸에틸케톤, 헥산, 테트라하이드로퓨란, 데칸, 에탄올, 메탄올, 이소프로판올, 아세트산에틸 또는 이들의 조합을 포함할 수 있다. At this time, the solvent mixed with the amorphous precursor is water, N-methylpyrrolidone, dimethylformamide, toluene, ethylene, dimethylacetamide, acetone, methyl ethyl ketone, hexane, tetrahydrofuran, decane, ethanol, methanol , Isopropanol, ethyl acetate or a combination thereof.
이때, 상기 비정질 탄소층은 음극 활물질 전체에 대하여 2 내지 5 중량%으로 포함될 수 있다. 만약, 상기 비정질 탄소층이 음극 활물질 전체에 대하여 2 중량% 미만으로 포함되는 경우에는 비정질 탄소층이 너무 얇아 코어인 천연흑연이 전해질에 의해 파괴되거나, 천연흑연까지 조면화되는 문제점이 발생할 수 있고, 5 중량% 초과로 포함되는 경우에는 리튬 이온의 출입이 어려운 문제점이 발생할 수 있다.  In this case, the amorphous carbon layer may be included in 2 to 5% by weight based on the entire negative active material. If the amorphous carbon layer is included in less than 2% by weight based on the entire negative electrode active material, the amorphous carbon layer is too thin so that the core of natural graphite is destroyed by the electrolyte or roughened to natural graphite, If it is included in more than 5% by weight may be a problem that is difficult to access the lithium ion.
또한, 본 발명에 따른 음극 활물질의 제조방법에 있어서, 단계 2는 상기 단계 1의 비정질 탄소층의 표면을 기계적 가공하여 조면화하는 단계이다(b). In addition, in the method of manufacturing the negative electrode active material according to the present invention, step 2 is a step of roughening the surface of the amorphous carbon layer of step 1 by mechanical processing (b).
상기 단계 2에서는 단계 1에서 제조된 코어(11) 표면을 감싸는 비정질 탄소층(13)의 표면을 기계적으로 가공하여 음극 활물질 표면을 조면화(15)하여 요철을 형성하고, 이와 같이 표면이 조면화된 음극활물질은 서로 맞닿은 활물질 간에 굴곡진 표면이 걸리는 앵커링 효과(anchoring effect)로 인해 바인더를 적게 사용하고도 접착력이 향상될 수 있고, 비표면적이 증가하는 효과를 얻을 수 있다. In step 2, the surface of the amorphous carbon layer 13 surrounding the surface of the core 11 manufactured in step 1 is mechanically processed to roughen the surface of the negative electrode active material (15) to form irregularities, and thus the surface is roughened. The negative electrode active material may have improved adhesion even with less binder due to the anchoring effect of the curved surface between the active materials in contact with each other, thereby increasing the specific surface area.
상기 단계 2의 기계적 가공은 단계 1에서 사용된 도 6에 나타낸 구형화 장비를 통해 수행될 수 있다. 전술한 바와 같이 본래 구형화 장비는 반원 형태의 구형화 커터를 사용하여 특정 물질을 구형화하는 데 사용될 수 있으나, 본 발명에서는 물질 표면의 조면화를 위해, 도 6에 나타낸 바와 같이 구형화 커터 대신 봉침 형태의 조면화 커터를 사용하여 비정질 탄소층의 표면을 깎지 않고 요철을 구비한 굴곡진 형상으로 제조할 수 있다. 그러나, 상기 단계 2의 기계적 가공이 반드시 구형화 장비를 통해 수행되는 것은 아니며, 비정질 탄소층의 표면을 조면화할 수 있는 기계적 가공법을 적절히 선택하여 사용할 수 있다. The mechanical processing of step 2 may be performed through the spheronization equipment shown in FIG. 6 used in step 1. As described above, the original spheronization equipment may be used to spheronize a specific material using a semicircular spherical cutter, but in the present invention, instead of the spherical cutter as shown in FIG. It is possible to produce a curved shape with irregularities without cutting the surface of the amorphous carbon layer by using a barbed roughening cutter. However, the mechanical processing of step 2 is not necessarily performed through the spheronization equipment, and a mechanical processing method capable of roughening the surface of the amorphous carbon layer may be appropriately selected and used.
본 발명의 방법에서는 상기 조면화 단계를 위하여, 모양과 크기가 다른 2 종의 조면화 커터를 이용할 수 있다. 즉, 면적이 큰 제1 조면화 커터를 사용하여 동그란 모양의 흑연을 크게 울퉁불퉁한 모양으로 만들어 준 다음(b-1), 작은 면적의 제2 조면화 커터를 사용하여 울퉁불퉁한 모양을 작게 만들어 주어서(b-2) 앵커링 효과가 나타나도록 할 수 있다.In the method of the present invention, two kinds of roughening cutters different in shape and size may be used for the roughening step. In other words, the large first surface roughening cutter is used to make the round graphite into a large bumpy shape (b-1), and the second surface roughing cutter with a small area makes the bumpy shape small. (b-2) The anchoring effect can be shown.
보다 구체적으로, 직경 10 ㎛ 의 제1 조면화 커터를 사용하여 500 rpm속도로 장비를 가동시켜 제1 조도면을 형성한 다음, 직경 2 ㎛의 제2 조면화 커터를 사용하여 200 rpm속도로 장비를 가동시켜 제2 조도면을 형성할 수 있다.More specifically, the equipment is operated at 500 rpm using a first roughening cutter having a diameter of 10 μm to form a first roughness surface, and then the equipment is operated at 200 rpm using a second roughening cutter having a diameter of 2 μm. Can be operated to form a second roughness surface.
그 결과, 상기 비정질 탄소층은 0.01 ㎛ 내지 5 ㎛의 표면 조도(Ra)를 갖도록 기계적 가공 될 수 있다. 만약, 상기 비정질 탄소층의 표면 조도가 0.01 ㎛ 미만인 경우에는 접착력 향상의 효과가 미미한 문제점이 있고, 5 ㎛ 초과인 경우에는 천연흑연이 전해질에 의해 파괴되는 문제점이 발생할 수 있다. As a result, the amorphous carbon layer may be mechanically processed to have a surface roughness Ra of 0.01 μm to 5 μm. If the surface roughness of the amorphous carbon layer is less than 0.01 μm, the effect of improving the adhesion is insignificant. If the surface roughness is more than 5 μm, natural graphite may be destroyed by the electrolyte.
구체적으로, 상기 비정질 탄소층은, 비정질 탄소층의 표면에 표면 조도(Ra) 1 ㎛ 내지 5 ㎛을 갖는 제1 조도면 및 상기 제1 조도면 표면에 표면 조도 0.01 ㎛ 내지 1 ㎛를 갖는 제2 조도면을 갖도록 기계적 가공 될 수 있다. In detail, the amorphous carbon layer may include a first roughness surface having a surface roughness Ra of 1 μm to 5 μm and a second roughness surface having a surface roughness of 0.01 μm to 1 μm on the surface of the amorphous carbon layer. It can be mechanically processed to have
보다 큰 크기의 조도를 갖는 제1 조도면은 활물질 간에 맞닿은 면끼리 서로 걸리는 앵커링 효과를 나타내어 바인더를 적게 사용하면서도 로딩율을 높이는 효과가 있고, 상기 제1 조도면 상에 보다 작은 크기의 조도를 갖는 제2 조도면은 음극 활물질의 표면적을 넓게 하는 효과가 있다. 따라서, 제1 조도면 및 제2 조도면을 모두 포함하는 본 발명의 음극 활물질을 사용하면 고로딩이면서도 높은 접착력을 가지고, 우수한 출력을 나타내는 음극을 제조할 수 있다. The first roughness surface having a larger roughness has an effect of increasing the loading rate while using fewer binders due to the anchoring effect of the surfaces contacted between the active materials, and the second roughness having a smaller roughness on the first roughness surface. Roughness surface has the effect of widening the surface area of the negative electrode active material. Therefore, by using the negative electrode active material of the present invention including both the first roughness surface and the second roughness surface, it is possible to manufacture a negative electrode having high loading while having high loading, and showing excellent output.
한편, 상기 조면화된 비정질 탄소층은, 조면화되기 전의 비정질 탄소층의 비표면적에 비해 1.5 내지 2.0 배 향상된 비표면적을 가질 수 있다. 만약, 조면화된 비정질 탄소층의 비표면적이 조면화되기 전의 비정질 탄소층에 비해 1.5 배 미만의 비표면적 증가율을 갖는 경우, 기대하는 앵커링 효과가 크게 나타나지 않아서 접착력 향상 폭이 미미하며, 2.0 배 초과의 비표면적 증가율을 갖는 경우 비표면적이 너무 커져서 초기효율의 감소 및 용량 저하가 발생한다.Meanwhile, the roughened amorphous carbon layer may have a specific surface area 1.5 to 2.0 times improved compared to the specific surface area of the amorphous carbon layer before roughening. If the specific surface area of the roughened amorphous carbon layer has a specific surface area increase rate of less than 1.5 times that of the amorphous carbon layer before roughening, the expected anchoring effect does not appear much, and thus the adhesion improvement range is insignificant, and more than 2.0 times. In the case of having a specific surface area increase rate of, the specific surface area becomes so large that the initial efficiency decreases and the capacity decreases.
또한, 본 발명의 다른 일 실시예에 따르면, In addition, according to another embodiment of the present invention,
집전체; 및Current collector; And
상기 집전체 상에 형성된 상기 음극 활물질을 포함하는 음극 합제층;을 포함하는 음극을 제공한다.It provides a negative electrode comprising a; negative electrode mixture layer comprising the negative electrode active material formed on the current collector.
상기 음극은 본 발명의 음극 활물질을 포함하는 음극 합제를 유기 용매에 혼합하여 만들어진 슬러리를 음극 집전체 상에 도포한 후 건조 및 압연하여 제조될 수 있다. 이때, 상기 음극 합제 및 상기 양극 합제 중 하나 이상은 바인더를 포함할 수 있으며, 특히 바인더로 PVDF(polyvinylidenefluoride)를 사용하는 것이 바람직하다.The negative electrode may be prepared by applying a slurry prepared by mixing the negative electrode mixture including the negative electrode active material of the present invention to an organic solvent on a negative electrode current collector, followed by drying and rolling. In this case, at least one of the negative electrode mixture and the positive electrode mixture may include a binder, and in particular, it is preferable to use polyvinylidene fluoride (PVDF) as a binder.
본 발명에 따른 조면화된 음극 활물질을 사용하면, 입자 사이에서 앵커링 효과가 발현되므로 동일한 바인더 함량에서 전극의 접착강도가 증가하며, 따라서 음극의 고로딩화를 구현할 수 있으면서도 과량의 바인더 사용으로 인해 이차전지의 저항이 증가하는 문제점을 해결할 수 있다. 또한, 조면화된 표면으로 인해 비표면적이 증가되므로, 리튬 이온의 출입이 용이해져 고출력 이차전지를 구현할 수 있는 효과가 있다.  When the roughened negative electrode active material according to the present invention is used, the anchoring effect is expressed between the particles, so that the adhesive strength of the electrode is increased at the same binder content, and thus secondary loading due to the use of an excessive amount of binder can be achieved. The problem that the resistance of a battery increases can be solved. In addition, since the specific surface area is increased due to the roughened surface, the entrance and exit of lithium ions is facilitated, and thus there is an effect of implementing a high output secondary battery.
또한, 본 발명은In addition, the present invention
상기 음극과, 양극 활물질을 포함하는 양극 합제가 도포되어 있는 양극, 및 전해액을 포함하는 이차전지를 제공한다.Provided is a secondary battery including the anode, a cathode coated with a cathode mixture including a cathode active material, and an electrolyte solution.
상기 이차전지의 상기 양극 활물질은 특별히 한정되지 않지만, 구체적으로 리튬 전이금속 산화물을 사용할 수 있다. 상기 리튬 전이금속 산화물로는, 예를 들면, LiCoO2 등의 LiㆍCo계 복합 산화물, LiNixCoyMnzO2 등의 LiㆍNiㆍCoㆍMn계 복합 산화물, LiNiO2 등의 LiㆍNi계 복합 산화물, LiMn2O4 등의 LiㆍMn계 복합 산화물 등을 들 수 있고, 이들을 단독 또는 복수 개 혼합하여 사용할 수 있다.Although the positive electrode active material of the secondary battery is not particularly limited, specifically, a lithium transition metal oxide may be used. Examples of the lithium transition metal oxide include Li.Co-based composite oxides such as LiCoO 2 , Li.Ni.Co.Mn-based composite oxides such as LiNi x Co y Mn z O 2 , and Li.sub.2 such as LiNiO 2 . Ni-based composite oxide may be mentioned, such as LiMn 2 O 4 of the Li-Mn composite oxide such, may be mixed alone or a plurality of them.
상기 양극 합제 및 음극 합제는 도전재를 포함할 수 있으며, 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 그라파이트; 카본블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 퍼니스 블랙, 램프 블랙, 서머 블랙 등의 카본블랙; 탄소 섬유나 금속 섬유 등의 도전성 섬유; 불화 카본, 알루미늄, 니켈 분말 등의 금속 분말; 산화아연, 티탄산 칼륨 등의 도전성 위스키; 산화 티탄 등의 도전성 금속 산화물; 폴리페닐렌 유도체 등의 도전성 소재 등이 사용될 수 있다. The positive electrode mixture and the negative electrode mixture may include a conductive material, and are not particularly limited as long as they have conductivity without causing chemical change in the battery. For example, graphite; Carbon blacks such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black and summer black; Conductive fibers such as carbon fibers and metal fibers; Metal powders such as carbon fluoride powder, aluminum powder and nickel powder; Conductive whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.
상기 양극 또는 음극은 집전체 상에 상기 양극 합제 또는 음극 합제가 도포되어 있는 형태일 수 있다. 상기 집전체는, 당해 전지에 화학적 변화를 유발하지 않으면서 도전성을 가진 것이라면 특별히 제한되는 것은 아니며, 예를 들어, 구리, 스테인리스 스틸, 알루미늄, 니켈, 티탄, 소성 탄소, 또는 알루미늄이나 스테인리스 스틸의 표면에 카본, 니켈, 티탄, 은 등으로 표면 처리한 것 등이 사용될 수 있다. The positive electrode or the negative electrode may have a form in which the positive electrode mixture or the negative electrode mixture is coated on a current collector. The current collector is not particularly limited as long as it is conductive without causing chemical change in the battery. For example, the surface of copper, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel Surface treated with carbon, nickel, titanium, silver, or the like can be used.
또한, 상기 전해액은 리튬염 함유 전해액으로서, 비수계 유기용매, 유기 고체 전해질, 무기 고체 전해질 등이 사용되지만 이들만으로 한정되는 것은 아니다.In addition, although the said electrolyte solution is a lithium salt containing electrolyte solution, although a non-aqueous organic solvent, an organic solid electrolyte, an inorganic solid electrolyte, etc. are used, it is not limited to these.
본 발명의 다른 일 실시예에 따르면, 상기 이차전지를 단위 셀로 포함하는 전지 모듈 및 이를 포함하는 전지팩을 제공한다. 상기 전지모듈 또는 전지팩은 저항이 낮고 고용량, 고출력 특성을 지닌 이차전지를 포함함으로써, 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. According to another embodiment of the present invention, a battery module including the secondary battery as a unit cell and a battery pack including the same are provided. The battery module or battery pack includes a secondary battery having low resistance, high capacity, and high output characteristics, such as a power tool, an electric vehicle (EV), a hybrid electric vehicle (HEV), and Electric vehicles, including plug-in hybrid electric vehicles (PHEVs), or any one or more of the power storage system can be used as a power source for the device.
이하, 본 발명이 속하는 기술 분야에서 통상의 지식을 가진 자가 용이하게 실시할 수 있도록 본 발명의 실시예에 대하여 상세히 설명한다. 그러나 본 발명은 여러 가지 상이한 형태로 구현될 수 있으며 여기에서 설명하는 실시예에 한정되지 않는다. Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.
실시예Example
실시예 1. 조면화된 음극 활물질을 포함하는 이차전지의 제조Example 1. Fabrication of Secondary Battery Containing Roughened Anode Active Material
(단계 1) 평균입경(D50)이 16 ㎛인 천연흑연(제품명: SG16) 1000g, 및 비정질 탄소층의 전구체인 콜타르 피치(coal tar pitch) 100g을 드럼 타입의 혼합기 내에서 2시간 동안 혼합한 후, 1150℃에서 600 분간 열처리하여 비정질 탄소층 (비표면적 3.3 ㎡/g)이 코팅된 천연흑연을 제조하였다. (Step 1) 1000 g of natural graphite (product name: SG16) having an average particle diameter (D 50 ) of 16 μm and 100 g of coal tar pitch, a precursor of an amorphous carbon layer, were mixed in a drum type mixer for 2 hours. Thereafter, heat treatment was performed at 1150 ° C. for 600 minutes to prepare natural graphite coated with an amorphous carbon layer (specific surface area of 3.3 m 2 / g).
상기 제조된 비정질 탄소층이 코팅된 천연흑연을 구형화 장비(장비명: AMD3)에 투입하고, 구형화 커터를 이용하여 2시간, 1000 rpm의 공정 조건(시간, 속도 등)에서 구형화하였다. Natural graphite coated with the amorphous carbon layer prepared above was added to a spheronization equipment (equipment name: AMD3), and spheronized at a process condition (time, speed, etc.) at 1000 rpm for 2 hours using a spherical cutter.
(단계 2) 상기 구형화된 비정질 탄소층이 코팅된 천연흑연을 봉침 형태의 직경 10 ㎛인 조면화 커터로 교체한 구형화 장비에 투입하고, 500 rpm의 속도로 가공하여 7 ㎛의 표면 조도를 가지는 제1 조도면을 형성하였다. 그 후, 직경 2 ㎛ 인 조면화 커터로 교체한 후, 200 rpm 속도로 가공하여 3 ㎛의 표면 조도를 가지는 제2 조도면을 형성하여, 표면이 조면화된 비정질 탄소층을 포함하는 음극활물질 (비표면적 4.1 ㎡/g)을 제조하였다. (Step 2) The spherical amorphous carbon layer-coated natural graphite was put into a spheronization apparatus replaced with a roughening cutter having a diameter of 10 μm in the form of a needle, and processed at a speed of 500 rpm to obtain a surface roughness of 7 μm. The branches formed the first roughness plane. Subsequently, after replacing with a roughening cutter having a diameter of 2 μm, the second active material was processed at 200 rpm to form a second roughness surface having a surface roughness of 3 μm, and the anode active material including an amorphous carbon layer whose surface was roughened (non- Surface area of 4.1 m 2 / g).
(단계 3) 상기 조면화된 비정질 탄소층이 코팅된 천연흑연 98g, 바인더인 PVDF 1g, 도전재인 카본블랙 1g를 혼합하여 음극 합제를 제조하였다. 상기 음극합제를 구리 집전체에 도포한 후, 120℃에서 진공오븐에서 건조하고 압연하여 음극을 제조하였다. (Step 3) The negative electrode mixture was prepared by mixing 98 g of the natural graphite coated with the roughened amorphous carbon layer, 1 g of PVDF as a binder, and 1 g of carbon black as a conductive material. The negative electrode mixture was coated on a copper current collector, dried at 120 ° C. in a vacuum oven, and rolled to prepare a negative electrode.
(단계 4) 상기 음극과 LiNi0 . 6Mn0 . 2Co0 . 2O2를 양극활물질로 사용한 양극 사이에 다공성 폴리에틸렌 분리막을 개재하고, 리튬 전해액을 주입하여, 리튬 이차전지를 제조하였다.(Step 4) LiNi 0 with the negative electrode . 6 Mn 0 . 2 Co 0 . A lithium secondary battery was prepared by interposing a porous polyethylene separator between the positive electrodes using 2 O 2 as a positive electrode active material and injecting a lithium electrolyte.
비교예 1. 조면화되지 않은 음극 활물질을 포함하는 이차전지의 제조Comparative Example 1. Fabrication of Secondary Battery Containing Unroughened Negative Active Material
상기 실시예 1에서 단계 2를 수행하지 않은 것을 제외하고는 상기 실시예 1과 마찬가지의 방법으로 비정질 탄소층 (표면 조도 0)이 코팅된 코어(천연흑연)를 포함하는 음극활물질과, 이를 포함하는 음극 및 이를 구비한 이차전지를 제조하였다. An anode active material comprising a core (natural graphite) coated with an amorphous carbon layer (surface roughness 0) in the same manner as in Example 1, except that Step 2 in Example 1 was not performed, and the same. A negative electrode and a secondary battery having the same were prepared.
실험예Experimental Example
실험예 1. 음극 활물질의 표면 관찰 Experimental Example 1. Surface observation of the negative electrode active material
상기 실시예 1 및 비교예 1에서 제조된 음극 활물질을 SEM(주사 전자 현미경)으로 관찰한 후, 그 결과를 도 3에 도시하였다. The negative electrode active materials prepared in Example 1 and Comparative Example 1 were observed with a scanning electron microscope (SEM), and the results are shown in FIG. 3.
도 3에 나타낸 바와 같이, (b) 조면화되지 않은 비교예 1의 음극 활물질의 경우, 전체적으로 매끄러운 표면을 가진 구형의 입자임을 알 수 있다. 그러나, (a) 조면화된 실시예 1의 음극 활물질의 경우, 약 3㎛의 표면 조도를 가지는 입자임을 알 수 있다. As shown in Figure 3, (b) in the case of the negative electrode active material of Comparative Example 1 not roughened, it can be seen that the spherical particles having a smooth surface as a whole. However, (a) in the case of the roughened anode active material of Example 1, it can be seen that the particles having a surface roughness of about 3㎛.
이와 같이, 본 발명에 따른 표면이 조면화된 음극 활물질은 이종(異種)의 크기를 가지는 조도면을 가지는 것을 알 수 있다. 더욱이, 상대적으로 큰 크기의 조도면으로 인해 앵커링 효과를 구현할 수 있고, 상대적으로 작은 크기의 조도면으로 인해 넓은 표면적을 나타낼 수 있음을 예측할 수 있다. As described above, it can be seen that the surface-negative anode active material according to the present invention has a roughness plane having a heterogeneous size. Furthermore, it can be predicted that the anchoring effect can be realized due to the relatively large roughness plane, and that a large surface area can be exhibited due to the relatively small roughness plane.
실험예 2.Experimental Example 2.
상기 실시예 1 및 비교예 1에서 제조된 음극의 접착강도를 알아보기 위해, 접착력 측정은 일반적으로 알려진 180 o 벗김 테스트 (peel test)로 진행하였다. 그 결과를 도 4에 나타내었다. In order to find out the adhesive strength of the negative electrode prepared in Example 1 and Comparative Example 1, the adhesion measurement was carried out by a commonly known 180 o peel test (peel test). The results are shown in FIG.
도 4에 나타낸 바와 같이, 조면화된 음극 활물질을 사용한 실시예 1의 음극의 접착력은 약 75 gf/10mm로 나타난 반면, 조면화되지 않은 음극 활물질을 사용한 비교예 1의 음극의 접착력은 약 30 gf/10mm으로, 본 발명의 실시예 1의 음극의 접착력이 약 2.5 배 정도 우수한 것을 알 수 있다.As shown in FIG. 4, the adhesion of the negative electrode of Example 1 using the roughened negative electrode active material was about 75 gf / 10mm, whereas the adhesion of the negative electrode of Comparative Example 1 using the non-roughened negative electrode active material was about 30 gf. / 10mm, it can be seen that the adhesion of the negative electrode of Example 1 of the present invention is about 2.5 times as excellent.
상기 결과로부터, 동일한 바인더 종류와 함량을 사용하는 음극이라 할지라도, 조면화된 표면을 갖는 음극 활물질을 사용한 경우 현저히 향상된 접착력을 나타내는 것을 알 수 있으며, 이는 조면화된 음극 활물질 간의 앵커링 효과에 기인한 것임을 알 수 있다. From the above results, even if the negative electrode using the same binder type and content, it can be seen that the use of the negative electrode active material having a roughened surface shows a significantly improved adhesion, which is due to the anchoring effect between the roughened negative electrode active material It can be seen that.
실험예 3.Experimental Example 3.
상기 실시예 1 및 비교예 1에서 제조된 상기 리튬 이차전지를 상온에서 SOC 50%의 조건에서 연속 방전특성(방전 출력 값: 160 mW)를 측정하였고, 그 결과를 도 5에 도시하였다.The lithium secondary batteries prepared in Example 1 and Comparative Example 1 were measured for continuous discharge characteristics (discharge output value: 160 mW) under SOC 50% at room temperature, and the results are shown in FIG. 5.
도 5에 나타낸 바와 같이, 시간에 따른 전압특성이 조면화된 음극 활물질을 포함하는 실시예 1의 이차전지가 조면화되지 않은 비교예 1의 이차전지에 비해 모든 시간 구간에서 우수한 것을 확인할 수 있다. As shown in FIG. 5, it can be confirmed that the secondary battery of Example 1 including the roughened negative electrode active material having a voltage characteristic over time is superior to the secondary battery of Comparative Example 1 that is not roughened in all time sections.
이를 통해, 조면화된 음극 활물질이 조면화되지 않은 음극 활물질에 비해 표면적이 넓고, 이에 따라 리튬 이온의 출입이 용이하므로 보다 고출력의 이차전지를 제공할 수 있음을 알 수 있다. As a result, the roughened negative electrode active material has a wider surface area than the non-roughened negative electrode active material, and thus it is easy to access lithium ions, thereby providing a secondary battery having a higher output.
이상에서 본 발명의 바람직한 실시예에 대하여 상세하게 설명하였지만 본 발명의 권리범위는 이에 한정되는 것은 아니며, 이하의 청구범위에서 정의하고 있는 본 발명의 기본 개념을 이용한 당업자의 여러 변형 및 개량 형태 또한 본 발명의 권리범위에 속하는 것이다.Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

Claims (20)

  1. 천연흑연을 포함하는 코어; 및A core comprising natural graphite; And
    상기 코어 표면에 형성된, 조면화(roughened)된 비정질 탄소층을 포함하는 쉘;을 포함하는 음극 활물질. And a shell comprising a roughened amorphous carbon layer formed on the surface of the core.
  2. 청구항 1에 있어서, The method according to claim 1,
    상기 천연흑연은 구형인 것인 음극 활물질. The natural graphite is a negative electrode active material.
  3. 청구항 1에 있어서,The method according to claim 1,
    상기 비정질 탄소층은 음극 활물질 전체 중량을 기준으로 2 중량% 내지 5 중량%로 포함되는 것인 음극 활물질. The amorphous carbon layer is 2 to 5% by weight based on the total weight of the negative electrode active material negative electrode active material.
  4. 청구항 1에 있어서,The method according to claim 1,
    상기 조면화된 비정질 탄소층의 표면 조도(Ra)는 0.01 ㎛ 내지 5 ㎛인 것인 음극 활물질. The surface roughness (Ra) of the roughened amorphous carbon layer is 0.01 μm to 5 μm.
  5. 청구항 1에 있어서,The method according to claim 1,
    상기 조면화된 비정질 탄소층은 표면 조도(Ra) 1 ㎛ 내지 5 ㎛을 갖는 제1 조도면, 및 상기 제1 조도면 표면에 표면 조도 0.01 ㎛ 내지 1 ㎛를 갖는 제2 조도면을 포함하는 것인 음극 활물질. The roughened amorphous carbon layer includes a first roughness surface having a surface roughness (Ra) of 1 μm to 5 μm, and a second roughness surface having a surface roughness of 0.01 μm to 1 μm on the surface of the first roughness surface. .
  6. 청구항 1에 있어서,The method according to claim 1,
    상기 비정질 탄소층은 석탄계 핏치, 석유계 핏치, 폴리비닐클로라이드, 메조페이스 핏치, 타르 및 저분자량 중질유로부터 선택되는 적어도 하나의 소프트 카본 원료; 폴리비닐알코올 수지, 퍼푸릴 알코올(furfuryl alcohol) 수지, 트리톤(triton), 구연산, 스테아르산, 수크로오스, 폴리불화비닐리덴, 카르복시메틸셀룰로오스, 히드록시프로필셀룰로오스, 재생셀룰로오스, 폴리비닐피롤리돈, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 모노머, 폴리아크릴산, 폴리아크릴나트륨, 폴리아크릴로니트릴, 글루코오스, 젤라틴, 당류, 페놀 수지, 나프탈렌 수지, 폴리아미드 수지, 퓨란 수지, 폴리이미드 수지, 셀룰로오스 수지, 스티렌 수지, 에폭시 수지 및 염화비닐 수지로부터 선택되는 적어도 하나의 하드 카본 원료; 또는 이들의 조합으로부터 제조된 것인 음극 활물질. The amorphous carbon layer comprises at least one soft carbon raw material selected from coal-based pitch, petroleum-based pitch, polyvinyl chloride, mesophase pitch, tar and low molecular weight heavy oil; Polyvinyl alcohol resin, furfuryl alcohol resin, triton, citric acid, stearic acid, sucrose, polyvinylidene fluoride, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polyethylene , Polypropylene, ethylene-propylene-diene monomer, polyacrylic acid, polyacrylic sodium, polyacrylonitrile, glucose, gelatin, sugars, phenol resin, naphthalene resin, polyamide resin, furan resin, polyimide resin, cellulose resin, styrene At least one hard carbon raw material selected from resins, epoxy resins and vinyl chloride resins; Or a negative electrode active material prepared from a combination thereof.
  7. 천연흑연의 표면에 비정질 탄소층을 형성하는 단계(단계 1); 및Forming an amorphous carbon layer on the surface of natural graphite (step 1); And
    상기 단계 1의 비정질 탄소층의 표면을 기계적 가공하여 조면화하는 단계(단계 2);를 포함하는 청구항 1의 음극 활물질의 제조방법. And roughening the surface of the amorphous carbon layer of step 1 by mechanical processing (step 2).
  8. 청구항 7에 있어서,The method according to claim 7,
    상기 단계 2의 기계적 가공은 구형화 장비를 통해 수행되는 것인 음극 활물질의 제조방법. Mechanical processing of step 2 is to be carried out through the spheronization equipment manufacturing method of the negative electrode active material.
  9. 청구항 8에 있어서,The method according to claim 8,
    상기 구형화 장비는 봉침 형태의 조면화 커터를 구비한 것인 음극 활물질의 제조방법. The spheronization equipment is a method of manufacturing a negative electrode active material having a roughening cutter in the form of a needle.
  10. 청구항 7에 있어서, The method according to claim 7,
    상기 단계 1의 천연흑연은 구형인 것인 음극 활물질의 제조방법. Natural graphite of step 1 is a method for producing a negative electrode active material will be spherical.
  11. 청구항 7에 있어서,The method according to claim 7,
    상기 단계 2에서 조면화된 비정질 탄소층은 음극 활물질 전체 중량을 기준으로 2 중량% 내지 5 중량%로 포함되는 것인 음극 활물질의 제조방법. The amorphous carbon layer roughened in the step 2 is 2 to 5% by weight based on the total weight of the negative electrode active material manufacturing method of the negative electrode active material.
  12. 청구항 7에 있어서,The method according to claim 7,
    상기 단계 2에서 조면화된 비정질 탄소층의 표면 조도(Ra)는 0.01 ㎛ 내지 5 ㎛인 것인 음극 활물질의 제조방법.Surface roughness (Ra) of the roughened amorphous carbon layer in the step 2 is 0.01 ㎛ to 5 ㎛ manufacturing method of the active material.
  13. 청구항 7에 있어서,The method according to claim 7,
    상기 단계 2에서 조면화된 비정질 탄소층은 표면 조도(Ra) 1 ㎛ 내지 5 ㎛을 갖는 제1 조도면 및 상기 제1 조도면 표면에 표면 조도 0.01 ㎛ 내지 1 ㎛를 갖는 제2 조도면을 포함하는 음극 활물질의 제조방법.The amorphous carbon layer roughened in step 2 includes a first roughness surface having a surface roughness Ra of 1 μm to 5 μm and a second roughness surface having a surface roughness of 0.01 μm to 1 μm on the surface of the first roughness surface. Manufacturing method.
  14. 청구항 7에 있어서,The method according to claim 7,
    상기 단계 2의 조면화된 비정질 탄소층의 비표면적은 조면화되기 전의 비정질 탄소층의 비표면적과 비교하여 1.5 배 내지 2.0 배 증가한 것인 음극 활물질의 제조방법.The specific surface area of the roughened amorphous carbon layer of step 2 is 1.5 to 2.0 times increased compared to the specific surface area of the amorphous carbon layer before roughening.
  15. 청구항 7에 있어서, The method according to claim 7,
    상기 비정질 탄소층은 석탄계 핏치, 석유계 핏치, 폴리비닐클로라이드, 메조페이스 핏치, 타르 및 저분자량 중질유로부터 선택되는 적어도 하나의 소프트 카본 원료; 폴리비닐알코올 수지, 퍼푸릴 알코올(furfuryl alcohol) 수지, 트리톤(triton), 구연산, 스테아르산, 수크로오스, 폴리불화비닐리덴, 카르복시메틸셀룰로오스, 히드록시프로필셀룰로오스, 재생셀룰로오스, 폴리비닐피롤리돈, 폴리에틸렌, 폴리프로필렌, 에틸렌-프로필렌-디엔 모노머, 폴리아크릴산, 폴리아크릴나트륨, 폴리아크릴로니트릴, 글루코오스, 젤라틴, 당류, 페놀 수지, 나프탈렌 수지, 폴리아미드 수지, 퓨란 수지, 폴리이미드 수지, 셀룰로오스 수지, 스티렌 수지, 에폭시 수지 및 염화비닐 수지로부터 선택되는 적어도 하나의 하드 카본 원료; 또는 이들의 조합으로부터 제조되는 것인 음극 활물질의 제조방법.The amorphous carbon layer comprises at least one soft carbon raw material selected from coal-based pitch, petroleum-based pitch, polyvinyl chloride, mesophase pitch, tar and low molecular weight heavy oil; Polyvinyl alcohol resin, furfuryl alcohol resin, triton, citric acid, stearic acid, sucrose, polyvinylidene fluoride, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polyethylene , Polypropylene, ethylene-propylene-diene monomer, polyacrylic acid, polyacrylic sodium, polyacrylonitrile, glucose, gelatin, sugars, phenol resin, naphthalene resin, polyamide resin, furan resin, polyimide resin, cellulose resin, styrene At least one hard carbon raw material selected from resins, epoxy resins and vinyl chloride resins; Or a method for producing a negative electrode active material is prepared from a combination thereof.
  16. 전극 집전체; 및Electrode current collectors; And
    상기 전극 집전체 상에 형성된 청구항 1의 음극 활물질을 포함하는 음극 합제층;을 포함하는 음극.And a negative electrode mixture layer comprising the negative electrode active material of claim 1 formed on the electrode current collector.
  17. 청구항 16의 음극, 양극 활물질을 포함하는 양극 합제가 도포되어 있는 양극, 상기 양극 및 양극 사이에 개재된 분리막 및 전해액을 포함하는 이차전지.A secondary battery comprising a cathode coated with a cathode, an anode active material including a cathode active material, a separator interposed between the cathode and the anode, and an electrolyte solution.
  18. 청구항 17의 이차전지를 단위셀로 포함하는 전지모듈.A battery module comprising the secondary battery of claim 17 as a unit cell.
  19. 청구항 18의 전지모듈을 포함하며, 중대형 디바이스의 전원으로 사용되는 것인 전지팩.A battery pack including the battery module of claim 18, which is used as a power source for medium and large devices.
  20. 청구항 19에 있어서, The method according to claim 19,
    상기 중대형 디바이스가 전기자동차, 하이브리드 전기자동차, 플러그-인 하이브리드 전기자동차 및 전력 저장용 시스템으로 이루어진 군에서 선택되는 것인 전지팩.The medium-to-large device is a battery pack that is selected from the group consisting of electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles and power storage systems.
PCT/KR2016/002861 2015-03-23 2016-03-22 Cathode active material and preparation method therefor WO2016153255A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201680012017.6A CN107408698B (en) 2015-03-23 2016-03-22 Negative active material and method for preparing same
US15/548,969 US10326126B2 (en) 2015-03-23 2016-03-22 Negative electrode active material and method of preparing the same

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR20150039933 2015-03-23
KR10-2015-0039933 2015-03-23
KR1020160033216A KR101817418B1 (en) 2015-03-23 2016-03-21 Negative electrode active material and method for preparing the same
KR10-2016-0033216 2016-03-21

Publications (1)

Publication Number Publication Date
WO2016153255A1 true WO2016153255A1 (en) 2016-09-29

Family

ID=56977627

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2016/002861 WO2016153255A1 (en) 2015-03-23 2016-03-22 Cathode active material and preparation method therefor

Country Status (1)

Country Link
WO (1) WO2016153255A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109952672A (en) * 2016-11-14 2019-06-28 日立化成株式会社 Lithium ion secondary battery cathode material, lithium ion secondary battery cathode and lithium ion secondary battery
CN114830376A (en) * 2019-12-20 2022-07-29 株式会社Posco Negative active material for lithium secondary battery and method for preparing same

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080039035A (en) * 2006-10-31 2008-05-07 강원대학교산학협력단 Negative electrode for using lithium secondary battery, and lithium secondary battery comprising the same
KR20140016899A (en) * 2011-02-28 2014-02-10 제이에무에나지 가부시키가이샤 Lithium-ion capacitor
KR20140082265A (en) * 2012-12-24 2014-07-02 주식회사 엘지화학 Anode For Cable type Secondary Battery, A Manufacturing Method of The Same And Cable type Secondary Battery Having The Same
JP2014127275A (en) * 2012-12-25 2014-07-07 Toyota Industries Corp Power storage device and method for manufacturing power storage device
KR20140094418A (en) * 2013-01-15 2014-07-30 강원대학교산학협력단 Negative active material for rechargeable lithium battery, method of preparing the same, and negative electrode and rechargeable lithium battery including the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20080039035A (en) * 2006-10-31 2008-05-07 강원대학교산학협력단 Negative electrode for using lithium secondary battery, and lithium secondary battery comprising the same
KR20140016899A (en) * 2011-02-28 2014-02-10 제이에무에나지 가부시키가이샤 Lithium-ion capacitor
KR20140082265A (en) * 2012-12-24 2014-07-02 주식회사 엘지화학 Anode For Cable type Secondary Battery, A Manufacturing Method of The Same And Cable type Secondary Battery Having The Same
JP2014127275A (en) * 2012-12-25 2014-07-07 Toyota Industries Corp Power storage device and method for manufacturing power storage device
KR20140094418A (en) * 2013-01-15 2014-07-30 강원대학교산학협력단 Negative active material for rechargeable lithium battery, method of preparing the same, and negative electrode and rechargeable lithium battery including the same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109952672A (en) * 2016-11-14 2019-06-28 日立化成株式会社 Lithium ion secondary battery cathode material, lithium ion secondary battery cathode and lithium ion secondary battery
CN114830376A (en) * 2019-12-20 2022-07-29 株式会社Posco Negative active material for lithium secondary battery and method for preparing same

Similar Documents

Publication Publication Date Title
WO2017204466A1 (en) Anode active material and lithium secondary battery comprising same
WO2019108039A2 (en) Anode and secondary battery comprising same
WO2015041450A1 (en) Porous silicon-based anode active material, and lithium secondary battery containing same
WO2014193124A1 (en) Porous silicon-based negative electrode active material, method for preparing same, and lithium secondary battery comprising same
WO2012165758A1 (en) Lithium secondary battery
WO2017164702A1 (en) Negative electrode and method for manufacturing same
WO2018217071A1 (en) Fabrication method of cathode for secondary battery, cathode for secondary battery fabricated thereby, and lithium secondary battery comprising same cathode
WO2015199384A1 (en) Lithium secondary battery
KR20190104895A (en) Negative electrode active material, preparing method of the same, negative electrode and lithium secondary battery including the same
WO2012096472A2 (en) Method for preparing a negative electrode active material
WO2019013511A2 (en) Positive electrode for lithium secondary battery, manufacturing method therefor, and lithium secondary battery comprising same
KR101817418B1 (en) Negative electrode active material and method for preparing the same
WO2021107586A1 (en) Positive electrode for secondary battery including flake graphite and secondary battery including same
WO2019093830A1 (en) Negative electrode active material, negative electrode comprising same negative electrode active material, and secondary battery comprising same negative electrode
WO2018194345A1 (en) Anode for lithium secondary battery, lithium secondary battery comprising same, and manufacturing method therefor
WO2021112607A1 (en) Method for producing positive electrode material for secondary battery
WO2016122196A1 (en) Electrode, and method for producing battery and electrode
WO2019050216A2 (en) Anode active material, anode comprising same anode active material, and secondary battery comprising same anode
WO2016153255A1 (en) Cathode active material and preparation method therefor
WO2020226329A1 (en) Functional separator having catalytic sites introduced thereinto, manufacturing method therefor, and lithium secondary battery comprising same
WO2019078506A2 (en) Method for preparing cathode active material for lithium secondary battery, cathode active material prepared thereby, cathode comprising same for lithium secondary battery, and lithium secondary battery
WO2018135929A1 (en) Negative electrode for lithium secondary battery, lithium secondary battery comprising same, and method for manufacturing same
WO2013187707A1 (en) Anode for lithium secondary battery, method for manufacturing same, and lithium secondary battery using same
WO2017142261A1 (en) Negative electrode manufacturing method and negative electrode
WO2020149618A1 (en) Method for preparing negative electrode active material

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16769073

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 15548969

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16769073

Country of ref document: EP

Kind code of ref document: A1