WO2024085297A1 - Matériau actif d'anode, et anode et batterie secondaire au lithium le comprenant - Google Patents

Matériau actif d'anode, et anode et batterie secondaire au lithium le comprenant Download PDF

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WO2024085297A1
WO2024085297A1 PCT/KR2022/016876 KR2022016876W WO2024085297A1 WO 2024085297 A1 WO2024085297 A1 WO 2024085297A1 KR 2022016876 W KR2022016876 W KR 2022016876W WO 2024085297 A1 WO2024085297 A1 WO 2024085297A1
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active material
negative electrode
less
weight
electrode active
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PCT/KR2022/016876
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English (en)
Korean (ko)
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최정현
정대수
노광철
김민지
오민주
김정환
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한국세라믹기술원
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    • 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
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • 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
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • 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
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • 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, a negative electrode containing the same, and a lithium secondary battery.
  • Lithium secondary batteries have a high voltage of 4 V, a wide operating temperature of -20 degrees to more than 50 degrees, a high power density of more than 1 kW/kg, and a high energy density of more than 100 Wh/kg, and research is being actively conducted around the world.
  • the lithium secondary battery is used in various fields such as portable mobile power sources such as laptops and mobile phones, as well as HEV (Hybrid Electric Vehicle), PHEV (Plug in Hybrid Electric Vehicle), EV (Electric Vehicle), and energy storage system (ESS).
  • HEV Hybrid Electric Vehicle
  • PHEV Plug in Hybrid Electric Vehicle
  • EV Electric Vehicle
  • ESS energy storage system
  • the anode material of a lithium secondary battery accounts for about 15% of the material cost of a lithium ion battery, ranking third after the anode material and separator.
  • a counter electrode material of the anode material it is a key material that determines the performance such as the capacity of the battery. .
  • Natural graphite has the advantage of high capacity and has been widely applied to existing IT LiB, but there are issues such as swelling of the battery volume to meet the needs of high performance such as electric vehicles/ESS.
  • Silicon-based anode active material which is emerging as a new material for this, has the highest theoretical capacity (4,200 mAh/g) as a cathode material, which is three times higher than that of graphite, but it also has the problem of volume expansion during charging and discharging.
  • volume expansion of a lithium secondary battery occurs during the process of insertion and desorption of lithium ions within the lithium secondary battery.
  • the volume expands rapidly, causing decomposition of the anode active material particles and subsequent loss of storage space for lithium ions, resulting in a rapid decrease in capacity. This problem occurs more seriously in silicon-based active materials, which are high-capacity negative electrode active materials.
  • the silicon-based active material absorbs and stores the maximum amount of lithium, it is converted to Li 4.4 Si, and volume expansion occurs by charging.
  • the volume increase rate due to charging expands to about 4.12 times compared to the volume of silicon before volume expansion. Accordingly, during charging and discharging, metals such as Si, Sn, and Al are alloyed with lithium, causing volume expansion and contraction, which causes metal micronization and deteriorates cycle characteristics.
  • anode active materials such as silicon-based anode active materials.
  • Patent Document 1 a silicon metal alloy mixture obtained by mixing silicon with one or more metals selected from the group 2, 13, 14, and 15 elements, primary mechanical processing, and powdering, carbon material powder compound, and carbon
  • a mixture of nanofibers, carbon nanotubes, or a mixture thereof, or a compound represented by it is disclosed that it has the effect of significantly improving the problem of conductivity decrease, surface side reaction problem, etc.
  • this method still has the problem that cycle deterioration occurs as the interface between each component is broken and the structure is destroyed due to the insertion and release of lithium, resulting in micronization.
  • Patent Document 2 discloses an active material particle structure in which a hollow portion is formed inside and silicon (Si) exists in a plate shape as a shell surrounding the hollow portion.
  • Patent Document 3 and Non-Patent Document 1 As another method to suppress the volume expansion of the negative electrode active material, in Patent Document 3 and Non-Patent Document 1, a carbon coating layer is formed on the surface of the electrode active material, and in Patent Document 4, a conductive polymer coating layer is formed on the surface of the electrode active material to reduce the volume of the negative electrode active material. It is mentioned that volume expansion can be suppressed.
  • Patent Document 5 describes a technology for producing a negative electrode with no change in the thickness of the electrode by forming a fiber composite of polyolefin fibers and PE fibers on the negative electrode active material layer, which has excellent elasticity and elastic recovery even when the active material layer expands and decreases in volume. It is mentioned.
  • non-patent document 2 reported a study on adding carbon nanofibers (CNF)
  • non-patent document 3 reported a study on adding carbon nanotubes (CNT).
  • Non-Patent Document 4 reports that an aqueous binder, which is a suitable binder for silicon-based active materials, surrounds the active material and forms a stable solid-electrolyte-interphase (SEI layer), thereby reducing irreversible capacity.
  • SEI layer solid-electrolyte-interphase
  • the surface of the negative electrode active material is coated with polyacrylic acid crosslinked using polyacrylic acid with a weight average molecular weight (Mw) of 1 million and 3,5-diaminobenzoic acid as a crosslinking agent, thereby forming a current collector and negative electrode active material layer. It is disclosed that the volume expansion of the negative electrode active material can be suppressed by increasing the binding force.
  • Mw weight average molecular weight
  • Patent Document 7 mentions that by forming a metal-substituted polyacrylic acid polymer coating layer formed on silicon-based particles, volume expansion due to insertion of lithium ions is reduced, thereby demonstrating high lifespan characteristics.
  • volume expansion of anode active materials still remains an unresolved problem. Because of this, it is particularly difficult to universally use silicon-based active materials.
  • SEI solid-electrolyte-interphase
  • a specific binder was selected and the surface of the negative electrode active material was coated using this.
  • An aqueous binder was selected as a binder candidate. If the molecular weight of the aqueous binder is high, it has elastic properties that can withstand volume expansion of the negative electrode active material, so the molecular weight is limited to a high molecular weight, and the solvent is used when coating with a high molecular weight aqueous binder. In order to overcome coating difficulties due to low solubility in solvents, negative active material particles were manufactured by applying the mechano-fusion (MF) method, a solvent-free dry coating method.
  • MF mechano-fusion
  • negative electrode active material particles were manufactured by coating the negative electrode active material with a dry coating method using a high molecular weight aqueous binder, and when these negative electrode active material particles are introduced into the negative electrode, the problems of lifespan characteristics and deterioration due to volume expansion are effectively solved. It was confirmed that this can be done, and that the advantages of high capacity and energy density of anode active materials, especially silicon-based active materials, can be more preferably implemented.
  • the present invention provides a negative electrode active material whose volume expands and contracts while inserting and releasing lithium ions; and a coating layer obtained by dry coating the negative electrode active material with an aqueous binder.
  • the negative electrode active material is one or more selected from the group consisting of materials capable of reversibly intercalating/deintercalating lithium ions, lithium metal, alloys of lithium metal, materials capable of doping and dedoping lithium, and transition metal oxides. am.
  • the material capable of doping and dedoping lithium is at least one selected from the group consisting of carbon-based active materials, silicon-based active materials, and Sn-based active materials.
  • the silicon-based active material is Si, SiOx (0 ⁇ x ⁇ 2), Si-C composite, Si-Q alloy (where Q is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element, Group 15 element, Group 16 element, It is an element selected from the group consisting of transition metals, rare earth elements, and combinations thereof, but not Si.
  • the aqueous binder is polyacrylic acid, polyvinyl alcohol, polyethylene glycol, polyacrylonitrile, polyacryl amide, carboxymethyl cellulose, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyvinylpyridine, and chlorosulfonated Polyethylene, polyester resin, acrylic resin, phenol resin, epoxy resin, gum arabic, styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluorine rubber, ethylene propylene. At least one selected from the group consisting of diene copolymers and combinations thereof.
  • the water-based binder has a weight average molecular weight (Mw) of 2 million g/mol to 7.5 million g/mol.
  • the dry coating is performed in a solvent-free process.
  • the coating layer exists in a layer-type that continuously covers the surface of the negative electrode active material or an island-type that is discontinuously located.
  • It contains 0.1 to 50 parts by weight of aqueous binder based on 100 parts by weight of the negative electrode active material particles.
  • Negative active material particles for a secondary battery including a negative electrode active material that expands and contracts while inserting and releasing lithium ions, and a coating layer obtained by dry coating the negative electrode active material with an aqueous binder; conductive material; and a binder.
  • the negative electrode active material is one or more selected from the group consisting of materials capable of reversibly intercalating/deintercalating lithium ions, lithium metal, alloys of lithium metal, materials capable of doping and dedoping lithium, and transition metal oxides. am.
  • the material capable of doping and dedoping lithium is at least one selected from the group consisting of carbon-based active materials, silicon-based active materials, and Sn-based active materials.
  • the silicon-based active material is Si, SiOx (0 ⁇ x ⁇ 2), Si-C composite, Si-Q alloy (where Q is an alkali metal, alkaline earth metal, Group 13 element, Group 14 element, Group 15 element, Group 16 element, It is an element selected from the group consisting of transition metals, rare earth elements, and combinations thereof, but not Si.
  • the aqueous binder is polyacrylic acid, polyvinyl alcohol, polyethylene glycol, polyacrylonitrile, polyacryl amide, carboxymethyl cellulose, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyvinylpyridine, and chlorosulfonated Polyethylene, polyester resin, acrylic resin, phenol resin, epoxy resin, gum arabic, styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluorine rubber, ethylene propylene. At least one selected from the group consisting of diene copolymers and combinations thereof.
  • the water-based binder has a weight average molecular weight (Mw) of 2 million g/mol to 7.5 million g/mol.
  • the coating layer exists in a layer-type that continuously covers the surface of the negative electrode active material or an island-type that is discontinuously located.
  • the negative electrode slurry Based on the total weight of solids in the negative electrode slurry, it contains 80% to 99% by weight of negative electrode active material particles, 0.1% to 20.0% by weight of conductive material, and 0.5% to 5.0% by weight of binder.
  • the binder is a water-based binder.
  • the aqueous binder is polyacrylic acid, polyvinyl alcohol, polyethylene glycol, polyacrylonitrile, polyacryl amide, carboxymethyl cellulose, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyvinylpyridine, and chlorosulfonated Polyethylene, polyester resin, acrylic resin, phenol resin, epoxy resin, gum arabic, styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluorine rubber, ethylene propylene. At least one selected from the group consisting of diene copolymers and combinations thereof.
  • the binder has a weight average molecular weight (Mw) of 150,000 g/mol to 750,000 g/mol.
  • the present invention is a current collector; and a negative electrode for a secondary battery including a negative electrode active material layer laminated on an upper surface of a current collector, wherein the negative electrode active material layer includes the above-mentioned negative electrode active material particles.
  • the present invention provides a secondary battery including a negative electrode, a positive electrode, a separator, and an electrolyte, wherein the negative electrode includes the above-mentioned negative electrode active material particles.
  • the negative electrode active material particles according to the present invention coat the negative electrode active material with a high molecular weight water-based polymer, thereby effectively suppressing the volume expansion/contraction problem caused by charging and discharging of the high-capacity negative electrode active material, thereby preventing fine differentiation of the negative electrode active material and thickening of the SEI layer. (thickening) can be prevented.
  • MF Mechano-fusion
  • conventional high molecular weight aqueous binders have low solubility in solvents. This can solve the problem of forming an uneven cathode surface when wet coating.
  • FIG. 1 is a schematic diagram of anode active material particles for secondary batteries according to the present invention.
  • Figure 2 is a cross-sectional view showing a negative electrode for a lithium secondary battery according to the present invention.
  • Coating layer 20 Base material
  • % means weight%, and 1ppm is 0.0001% by weight.
  • Figure 1 is a schematic diagram of anode active material particles 10 for secondary batteries according to the present invention.
  • the negative electrode active material particles 10 include a negative electrode active material 11 whose volume expands and contracts while inserting and releasing lithium ions; and a coating layer 13 obtained by dry coating the negative electrode active material 11 with an aqueous binder.
  • the negative electrode active material 11 includes, for example, a material capable of reversibly intercalating/deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide. do.
  • the lithium metal alloy includes lithium and Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al and Sn. Any alloy of metals of choice may be used.
  • the lithium metal alloy includes lithium and Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al and Sn. Any alloy of metals of choice may be used.
  • a material capable of doping and dedoping lithium may be, for example, a carbon-based active material.
  • carbon-based active materials include crystalline carbon, amorphous carbon, or a combination of these.
  • the crystalline carbon include graphite such as amorphous, plate-shaped, flake, spherical or fibrous natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon ( hard carbon), mesophase pitch carbide, calcined coke, etc.
  • Materials capable of doping and dedoping lithium include, for example, Si, SiOx (0 ⁇ x ⁇ 2), Si-C composite, Si-Q alloy (where Q is an alkali metal, an alkaline earth metal, a group 13 element, a group 14 element, 15 Silicon-based active materials such as elements selected from the group consisting of group elements, group 16 elements, transition metals, rare earth elements, and combinations thereof, but not Si, may be used, and at least one of these may be mixed with SiO 2 . It may be possible.
  • the element Q includes Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, One selected from the group consisting of Se, Te, Po, and combinations thereof can be used.
  • silicon-based active materials containing Si have the advantage of high initial capacity and maintaining capacity even after repeated cycles.
  • Materials capable of doping and dedoping lithium include Sn, SnO 2 , S n -R (where R is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element, a Group 15 element, a Group 16 element, a transition metal, and a rare earth element).
  • Sn-based active materials such as elements selected from the group consisting of elements and combinations thereof, but not Sn, may be included, and at least one of these may be mixed with SiO 2 .
  • the elements R include Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, One selected from the group consisting of Se, Te, Po, and combinations thereof can be used.
  • the Si-C composite, or Si-Q alloy is a form in which Si nanoparticles are coated on the surface of a carbon-based material or metal (Q), such as graphite or metal (Q), or pores of graphite or metal (Q). It may be in a form impregnated within.
  • Si-C composite, Si-Q alloy, etc. may have a core-shell type structure.
  • the core is Si particles, Si, SiOx, Si-C composite, Si-Q alloy, Sn, SnO2, or Sn-R
  • the shell is other Si particles, Si, SiOx, Si-C. It may be any one of composite, Si-Q alloy, Sn, SnO 2 , or Sn-R.
  • a metal of the same material as the current collector of the negative electrode may be used as the shell.
  • lithium titanium oxide such as Li 4 Ti 5 O 12 can be used.
  • the negative electrode active material 11 described above has a large degree of volume expansion during the charging and discharging process of the battery, and microdifferentiation of the active material particles occurs due to mechanical stress generated when reacting with lithium ions. Due to the micronization, electrical contact between particles is lost and a new surface of the micronized particles is revealed, resulting in a significant lithium loss reaction due to the continuous formation of an SEI layer. As a result, it causes problems with deterioration of lifespan characteristics due to volume expansion of the anode active material, making commercialization difficult. This occurs more seriously in high-capacity silicon-based anode active materials.
  • the coating layer 13 is formed on the surface of the negative electrode active material 11 with an aqueous binder using a dry coating method, thereby effectively solving the problem of deterioration of life characteristics caused by volume expansion of the negative electrode active material 11, especially the high-capacity silicon-based active material. This can be done, and the advantages of high capacity and energy density of silicon-based active materials can be more preferably implemented.
  • Water-based binders have hydrophilic properties and are generally insoluble in electrolytes or electrolyte solutions used in lithium secondary batteries. These characteristics can provide strong stress or tensile strength to the water-based binder when applied to a negative electrode or lithium secondary battery, and thus can effectively suppress volume expansion/contraction problems due to charging and discharging of the negative electrode active material 11. .
  • the present invention forms a coating layer 13 on the surface of the anode active material 11 with an aqueous binder, and uses an aqueous binder as the binder used in the slurry composition for producing the anode.
  • Water-based binders have the advantage of high elasticity and stress, but when used alone, they cause bending of the cathode, cracks due to bending, and deterioration of lifespan characteristics.
  • the volume expansion/contraction problem of the negative electrode active material 11 is effectively solved by varying the molecular weight of the water-based binder formed in the coating layer 13 of the negative electrode active material 11 and the water-based binder used in the slurry composition for producing the negative electrode. It is possible to improve the lifespan characteristics and solve the problem of bending when manufacturing a thin film cathode, making it possible to implement a cathode with a thin thickness and high energy density.
  • Aqueous binders that can be used include polyacrylic acid, polyvinyl alcohol, polyethylene glycol, polyacrylonitrile, polyacryl amide, carboxymethyl cellulose, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyvinylpyridine, and chlorine.
  • Sulfonated polyethylene polyester resin, acrylic resin, phenol resin, epoxy resin, gum arabic, styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluorine rubber,
  • One or more types selected from the group consisting of ethylene propylene diene copolymer and combinations thereof are possible.
  • polyacrylic acid polyvinyl alcohol, polyethylene glycol, etc.
  • polyacrylic acid may be preferably used.
  • the water-based binder of the present invention is distinguished from that in which hydrogen in the water-based binder is replaced with Li, Na, or Ca, etc.
  • the water-based binder used in the coating layer 13 of the negative electrode active material 11 has a high molecular weight with a weight average molecular weight (Mw) of 2 million g/mol or more.
  • Mw weight average molecular weight
  • the high molecular weight aqueous binder has excellent binding properties for the negative electrode active material 11 and elasticity and stiffness that can withstand volume expansion. For example, in the case of polyacrylic acid, a strong interaction occurs between the carboxy group of acrylic acid and the hydroxy group of silicone, thereby ensuring the above-mentioned effect.
  • the water-based binder used in the coating layer 13 has a weight average molecular weight of 2 million g/mol or more, 2.5 million g/mol or more, 3 million g/mol or more, 3.5 million g/mol or more, or 4 million g/mol.
  • 4.5 million g/mol or more 5 million g/mol or more, 5.5 million g/mol or more, 6 million g/mol or more, 6.5 million g/mol or more, 7.5 million g/mol or less, 7 million g/mol or less , 6.5 million g/mol or less, 6 million g/mol or less, 5.5 million g/mol or less, 5 million g/mol or less, 4.5 million g/mol or less, 4 million g/mol or less, 3.5 million g/mol or less, It has a range of less than 3 million g/mol and less than 2.5 million g/mol.
  • 2 million g/mol or more Preferably, 2 million g/mol or more, 2.5 million g/mol or more, 3 million g/mol or more, 3.5 million g/mol or more, 7.5 million g/mol or less, 7 million g/mol or less, 6.5 million g/mol
  • the range is 6 million g/mol or less, 5.5 million g/mol or less, 5 million g/mol or less, 4.5 million g/mol or less, and 4 million g/mol or less.
  • the weight average molecular weight (Mw) is the weight average molecular weight (Mw) converted to polystyrene measured by gel permeation chromatography (GPC).
  • the coating method of the negative electrode active material 11 using a high molecular weight aqueous binder may be a dry method different from wet coating methods such as conventional sol-gel process, dip coating, and spray coating.
  • the mechano-fusion (MF) method which is a solvent-free dry coating method, can be used.
  • the mechanofusion method is a method of diffusion and immobilization by applying mechanical energy to the child particles on the surface of the parent particle and adding heat energy.
  • the negative electrode active material 11 is mixed with the particle-state negative electrode active material 11 and the particle-state aqueous binder.
  • a water-based binder coating layer 13 is formed on the surface.
  • Devices for performing the mechano fusion method include, for example, a high energy ball mill device, a planetary mill device, a stirred ball mill device, and a vibrating mill device. etc., of which mechanical alloying may be performed in a high-energy ball mill device, but is not limited thereto.
  • the water-based binder coating layer 13 formed through the mechanofusion method covers the particles of the negative electrode active material 11.
  • the water-based binder coating layer 13 is about 0.1% to about 10% of the particle surface of the negative electrode active material 11, for example, the ratio of the coating layer 13 to the negative electrode active material 11 is about 0.5% to about 99.5%, about 2.
  • the binder coating layer may cover the negative electrode active material from % to about 98%, from about 5% to about 95%, or from about 10% to about 90%.
  • the coating layer 13 may be a capsule or shell that partially covers, surrounds, or encapsulates the particles of the negative electrode active material 11.
  • the coating layer 13 may exist in a layer-type that continuously covers the surface of the negative electrode active material 11, or may exist in an island-type discontinuously located on the surface of the negative electrode active material. It may be possible.
  • the negative electrode active material particles 10 obtained through the mechanofusion method may have spaced portions, that is, pores, formed by the negative electrode active material 11 and the water-based binder particles.
  • the volume expansion of the negative electrode active material 11 is sucked in by the pores, thereby minimizing the volume expansion that occurs when the negative electrode active material is used, preventing micronization of the negative electrode active material 11, and preventing thickening of the SEI layer. It can be suppressed.
  • the high elasticity and strength of the high molecular weight aqueous binder allows it to sufficiently withstand volume expansion of the negative electrode active material 11.
  • the negative electrode active material particles 10 using the mechanofusion method are made by rotating the negative electrode active material 11 on the particles and a high molecular weight aqueous binder on the particles with a rotational force of 500 rpm to 5000 rpm in a mechanofusion device. can do. If the rotational force is outside the above range, dry coating may not work well.
  • the mechanofusion process may be performed by rotating the machine at a low rotation speed of 500 rpm to 1,500 rpm for 5 to 30 minutes and then rotating it at a high speed of 2,000 to 4,000 rpm for 5 to 30 minutes.
  • the water-based binder coated using the mechanofusion method of the present invention does not undergo additional processes such as cross-linking in addition to coating, and is different from the cross-linked water-based binder.
  • additional heat treatment for crosslinking is inevitable even if wet coating is performed or a dry mechanofusion method is performed.
  • This effect is different from the effect that can be obtained when using a wet coating method using a solvent or a low molecular weight aqueous binder.
  • the coating on the negative electrode active material 11 is not uniform due to the low dispersibility of the water-based binder, resulting in the problem of producing a non-uniform negative electrode with an uneven surface when manufacturing the negative electrode through slurry composition production.
  • the use of a low molecular weight aqueous binder has relatively low elasticity and cannot sufficiently withstand the volume expansion of the negative electrode active material 11.
  • the elasticity is low, and the effect according to the present invention cannot be secured due to the absence of the spaced portion.
  • the particles of the negative electrode active material 11, the water-based binder particles, their content ratio, and the thickness of the coating layer 13 may be limited.
  • the average particle diameter of particles can be defined as the particle size based on 50% of the particle size distribution.
  • the average particle diameter (D50) of the particles according to an embodiment of the present invention can be measured using, for example, a laser diffraction method.
  • the laser diffraction method is generally capable of measuring particle diameters ranging from the submicron region to several millimeters, and can obtain results with high reproducibility and high resolution.
  • the average particle diameter (D50) of the negative electrode active material 11 used in the present invention is more than 0 ⁇ m and less than 20 ⁇ m, specifically 0.01 ⁇ m or more, 0.05 ⁇ m or more, 0.1 ⁇ m or more, 0.15 ⁇ m or more, 0.2 ⁇ m or more, 0.5 ⁇ m or more, 1 More than ⁇ m, more than 1.2 ⁇ m, more than 1.5 ⁇ m, more than 2.0 ⁇ m, more than 2.5 ⁇ m, more than 3.0 ⁇ m, more than 3.5 ⁇ m, more than 4.0 ⁇ m, more than 4.5 ⁇ m, more than 5.0 ⁇ m, more than 5.5 ⁇ m, more than 6.0 ⁇ m, more than 6.5 ⁇ m , 7.0 ⁇ m or more, 7.5 ⁇ m or more, 8.0 ⁇ m or more, 8.5 ⁇ m or more, 9.0 ⁇ m or more, 9.5 ⁇ m or more, 10.0 ⁇ m or more, 10.5 ⁇ m or more, 11.0 ⁇
  • the average particle diameter of the negative electrode active material 11 is too small, side reactions with the electrolyte may increase and lifespan performance may be reduced, and if the average particle diameter is too large, volume expansion may be large during charging and discharging, which may cause particle cracks, thus causing lifespan performance. This may deteriorate.
  • excellent output and initial efficiency can be appropriately balanced, excellent tap density can be exhibited, and excellent loading amount can be exhibited during electrode coating.
  • the average particle diameter of the water-based binder is less than the above range, agglomeration may occur during the manufacturing process, and conversely, if it exceeds the above range, uniform reaction with lithium is difficult, and the lifespan characteristics and thickness expansion inhibition characteristics may be greatly reduced.
  • the thickness of the water-based binder coating layer 13 may be 0.01 ⁇ m or more and 20 ⁇ m or less. Specifically, 0.01 ⁇ m or more, 0.05 ⁇ m or more, 0.1 ⁇ m or more, 0.15 ⁇ m or more, 0.2 ⁇ m or more, 0.5 ⁇ m or more, 1 ⁇ m or more, 1.2 ⁇ m or more, 1.5 ⁇ m or more, 2.0 ⁇ m or more, 2.5 ⁇ m or more, 3.0 ⁇ m or more , 3.5 ⁇ m or more, 4.0 ⁇ m or more, 4.5 ⁇ m or more, 5.0 ⁇ m or more, 5.5 ⁇ m or more, 6.0 ⁇ m or more, 6.5 ⁇ m or more, 7.0 ⁇ m or more, 7.5 ⁇ m or more, 8.0 ⁇ m or more, 8.5 ⁇ m or more, 9.0 ⁇ m or more, 9.5 More than ⁇ m, more than 10.0 ⁇ m, more than 10.5 ⁇ m, more
  • the thickness of the coating layer 13 of the water-based binder is less than the above range, the volume expansion of the negative electrode active material 11 cannot be sufficiently suppressed. Conversely, if the above range is exceeded, the mobility of lithium ions may be impaired and resistance may increase.
  • the negative electrode active material particles 10 including the negative electrode active material 11 and the water-based binder coating layer 13 of the present invention have an average particle diameter (D50) of 0.02 ⁇ m or more and less than 30 ⁇ m.
  • D50 average particle diameter
  • the negative electrode active material particles 10 have an average particle diameter within the above range, excellent electrode manufacturing process efficiency and electrode density can be obtained.
  • the negative electrode active material particles 10 of the present invention contain an aqueous binder of 0.1 parts by weight to 50 parts by weight based on 100 parts by weight of the negative electrode active material 11. Specifically, 0.1 parts by weight or more, 0.2 parts by weight or more, 0.5 parts by weight or more, 1.0 parts by weight or more, 5.0 parts by weight or more, 10.0 parts by weight or more, 15.0 parts by weight or more, 20.0 parts by weight or more, 25.0 parts by weight or more, 30.0 parts by weight or more. parts or more, 35.0 parts by weight or more, 40.0 parts by weight or more, 45.0 parts by weight or more, and 47.0 parts by weight or more.
  • it is 5.0 parts by weight or less, 1.0 parts by weight or less, 0.5 parts by weight or less, and 0.3 parts by weight or less.
  • the negative electrode for a lithium secondary battery of the present invention includes a negative electrode active material 11 whose volume expands and contracts while inserting and releasing lithium ions, and a coating layer 13 obtained by dry coating the negative electrode active material 11 with an aqueous binder. Active material particles (10); conductive material; and a binder.
  • the negative electrode active material particles 10 described above may be used as the negative electrode active material particles 10.
  • Conductive materials are used to further improve the conductivity of the negative electrode active material. These conductive materials are not particularly limited as long as they have conductivity without causing chemical changes in the battery, and examples include graphite such as natural graphite or artificial graphite; Carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, 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 may be used.
  • graphite such as natural graphite or artificial graphite
  • Carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black
  • Conductive fibers such as carbon fiber and metal fiber
  • Metal powders such as carbon fluoride, aluminum, and nickel powder
  • Conductive whiskeys such as zinc oxide and potassium titanate
  • Conductive metal oxides
  • acetylene black (Chevron Chemical Company, Denka Black (Denka Singapore Private Limited), Gulf Oil Company products, etc.), Ketjenblack, and EC series. (from Armak Company), Vulcan XC-72 (from Cabot Company), and Super P (from Timcal).
  • the binder may be a water-based binder, but is not limited thereto.
  • the water-based binder is used in the water-based binder mentioned in the negative electrode active material particles 10, and the same or different water-based binders may be used.
  • the same water-based binder used in the negative electrode active material may be used to increase bonding strength.
  • the binder has a lower molecular weight than the water-based binder used in the negative electrode active material particles 10 to enable wet coating.
  • the binder has a weight average molecular weight of 150,000 g/mol or more, 170,000 g/mol or more, 200,000 g/mol or more, 250,000 g/mol or more, 300,000 g/mol or more, 350,000 g/mol or more, or 400,000 g/mol or more. g/mol or more, 450,000 g/mol or more, 500,000 g/mol or more, 550,000 g/mol or more, 600,000 g/mol or more, 650,000 g/mol or more, and 700,000 g/mol or more.
  • 150,000 g/mol or more 170,000 g/mol or more, 200,000 g/mol or more, 250,000 g/mol or more, 300,000 g/mol or more, 350,000 g/mol or more, 400,000 g/mol or more.
  • mol or more 450,000 g/mol or more, 500,000 g/mol or less, 750,000 g/mol or less, 700,000 g/mol or less, 650,000 g/mol or less, and 600,000 g/mol or less. More preferably, it has a range of 300,000 g/mol or more, 350,000 g/mol or more, 400,000 g/mol or more, 700,000 g/mol or less, 650,000 g/mol or less, and 600,000 g/mol or less. .
  • a binder within this range exhibits high dispersing power and can uniformly disperse the negative electrode active material particles 10 and the conductive material.
  • the negative electrode active material particles 10 have excellent compatibility with the water-based polymer of the coating layer 13, thereby increasing adhesion, thereby increasing the adhesion between the negative electrode active material particles 10 and the current collector to prevent interfacial peeling.
  • An anode slurry composition for a lithium secondary battery can be prepared by a known method.
  • the slurry composition according to one embodiment may be prepared by adding the negative electrode active material particles 10, a conductive material, and a binder to an aqueous solvent and then uniformly mixing them.
  • the negative electrode active material particles 10 in the negative electrode slurry composition are 80% to 99% by weight based on the total weight of the solid content of the negative electrode slurry, and specifically, 80% by weight or more, 85% by weight or more, 90% by weight or more, and 95% by weight. 97% by weight or more, 98% by weight or more, 99% by weight or less, 98% by weight or less, 97% by weight or less, 95% by weight or less, 90% by weight or less, 85% by weight or less, 82% by weight or less. have At this time, if the content of the negative electrode active material particles 10 is less than the above range, the capacity and lifespan characteristics of the lithium secondary battery may be significantly reduced.
  • the content of the conductive material and binder may be relatively reduced, thereby reducing the conductivity of the negative electrode containing the negative electrode active material particles 10 and the adhesion between the negative electrode active material particles 10 and the negative electrode current collector.
  • the conductive material in the anode slurry composition is 0.1% to 20.0% by weight based on the total weight of the solid content of the anode slurry, specifically 0.1% by weight or more, 0.5% by weight or more, 1.0% by weight or more, 3.0% by weight or more, 5.0% by weight or more. or more, 10.0% by weight or more, 15.0% by weight or more, 17.0% by weight or more, 19.0% by weight or more, and 19.5% by weight or more. In addition, 20% by weight or less, 19.5% by weight or less, 19.0% by weight or less, 17.0% by weight or less, 15.0% by weight or less, 10.0% by weight or less, 5.0% by weight or less, 3.0% by weight or less, 1.0% by weight or less, 0.5% by weight or less.
  • the range is 0.2% by weight or less.
  • the content of the conductive material is less than the above range, there may be difficulty in providing conductivity between the negative electrode active material particles 10 and the negative electrode current collector due to the insufficient amount of the conductive material.
  • the content of the negative electrode active material particles 10 may be relatively reduced, thereby deteriorating the capacity and lifespan characteristics of the lithium secondary battery.
  • the binder in the negative electrode slurry composition is 0.5% to 5.0% by weight based on the total weight of solids of the negative electrode slurry, specifically 0.5% by weight or more, 0.7% by weight or more, 1.0% by weight or more, 1.5% by weight or more, 2.0% by weight. or more, 2.5% by weight or more, 3.0% by weight or more, 3.5% by weight or more, 4.0% by weight or more, and 4.5% by weight or more.
  • the content of the binder is less than the above range, the bonding strength between the negative electrode active material particles 10 and the conductive material and the bonding force to the current collector may be reduced. Conversely, if the above range is exceeded, the content of the negative electrode active material particles 10 may be relatively reduced, thereby deteriorating the capacity and lifespan characteristics of the lithium secondary battery.
  • the solvent may be an aqueous solvent, but is not limited thereto.
  • the aqueous solvent includes not only water but also alcohols such as isopropyl alcohol, methyl alcohol, ethyl alcohol, and t-butyl alcohol, and N-methyl alcohol.
  • a solvent mixed with 40% by weight or less of additives such as cyclic amides such as N-Methyl pyrrolidone based on water may be used.
  • the aqueous solvent may be a solvent to which a metal salt is added.
  • the film includes the above-mentioned compounds such as Li 2 CO 3 , LiOCH 3 , LiOC 2 H 5 , or Li 2 O.
  • Components that make up SEI may be included. Since the components constituting the SEI are water-soluble, they are uniformly included in the film located on the outer surface of the negative electrode active material particles 10 in the negative electrode slurry composition and exist together in the form of a film to perform the same or similar function as SEI, thereby forming the negative electrode. Initial irreversibility can be minimized.
  • the aqueous solvent has a solid concentration of 15% by weight or more, 20% by weight, 25% by weight, or 30% by weight, including the anode active material, binder, and optionally a conductive material. It is % by weight or more, 35% by weight or more, 40% by weight or more, and 42% by weight or more. In addition, it has a range of 45% by weight or less, 42% by weight or less, 40% by weight or less, 35% by weight or less, 30% by weight or less, 25% by weight or less, 20% by weight or less, and 17% by weight or less. Preferably, it has a range of 20% by weight or more, 23% by weight or more, 30% by weight or less, and 27% by weight or less.
  • the negative electrode slurry composition may additionally include a thickener.
  • the thickener may be a cellulose-based compound, for example, one or more selected from the group consisting of carboxymethylcellulose (CMC), hydroxymethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose, and specifically carboxymethylcellulose. (CMC) can be
  • the negative electrode slurry composition contains the thickener in an amount of 0.1% to 3% by weight based on the total weight of solids of the negative electrode slurry, specifically 0.1% by weight or more, 0.5% by weight or more, 1.0% by weight or more, 1.5% by weight or more, It is 2.0% by weight or more, 2.5% by weight or more. Additionally, it is 3.0% by weight or less, 2.5% by weight or less, 2.0% by weight or less, 1.5% by weight or less, 1.0% by weight or less, and 0.5% by weight or less. Preferably, it is 0.5% by weight or more, 1.0% by weight or more, and 2.5% by weight or less, and 2.0% by weight or less.
  • the negative electrode slurry composition contains the thickener in the above range, an appropriate thickening effect can be achieved to ensure storage stability of the negative electrode slurry composition, and the thickener is included in the negative electrode slurry in an amount that does not affect the performance of the battery. You can.
  • the negative electrode slurry composition may further include a dispersant, and the dispersant may specifically be an aqueous dispersant.
  • the dispersing agent includes cellulose-based compounds, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetal, polyvinyl ether, polyvinyl sulfonic acid, polyvinyl chloride (PVC), polyvinylidene fluoride, chitosan, starch, and amyl.
  • Rose (amylose), polyacrylamide, poly-N-isopropylacrylamide, poly-N,N-dimethylacrylamide, polyethyleneimine, polyoxyethylene, poly(2-methoxyethoxyethylene), poly(acrylamide) -co-diallyldimethylammonium chloride), acrylonitrile/butadiene/styrene (ABS) polymer, acrylonitrile/styrene/acrylic ester (ASA) polymer, acrylonitrile/styrene/acrylic ester (ASA) polymer and propylene carbonate.
  • ABS acrylonitrile/butadiene/styrene
  • ASA acrylonitrile/styrene/acrylic ester
  • ASA acrylonitrile/styrene/acrylic ester
  • a mixture of styrene/acrylonitrile (SAN) copolymer, or methyl methacrylate/acrylonitrile/butadiene/styrene (MABS) polymer may be used, and any one or a mixture of two or more of these may be used.
  • SAN styrene/acrylonitrile
  • MABS methyl methacrylate/acrylonitrile/butadiene/styrene
  • the anode slurry contains the dispersant in an amount of 0.01% to 0.5% by weight based on the total weight of solids of the anode slurry, specifically 0.01% by weight or more, 0.05% by weight or more, 0.1% by weight or more, 0.2% by weight or more, 0.3% by weight. % or more, 0.4% by weight or more, or 0.45% by weight or more. Additionally, it is 0.5% by weight or less, 0.45% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, and 0.05% by weight or less. Preferably, it is 0.05% by weight or more, 0.1% by weight or more, and 0.5% by weight or less, or 0.3% by weight or less.
  • the dispersant can appropriately improve the dispersibility of the negative electrode active material, and the dispersant is included in the negative electrode slurry within a certain amount and does not deteriorate battery performance.
  • fillers, etc. may be additionally included in the water-based cathode slurry.
  • the filler can be used as a component to suppress expansion of the negative electrode, and is not particularly limited as long as it is a fibrous material that does not cause chemical changes in the secondary battery.
  • olipine polymers such as polyethylene and polypropylene
  • Fibrous materials such as glass fiber and carbon fiber may be used.
  • Figure 2 is a cross-sectional view showing the negative electrode 100 for a lithium secondary battery according to the present invention.
  • the negative electrode 100 for a lithium secondary battery includes a current collector 50; and a negative electrode active material layer 60 laminated on the upper surface of the current collector 50.
  • the negative electrode active material layer 60 is manufactured from the negative electrode slurry composition described above, and has negative electrode active material particles 10 dispersed in a substrate 20 containing a binder and a conductive material.
  • the negative electrode 100 may be manufactured by coating the upper surface of the negative electrode current collector 50 with the negative electrode slurry composition described above, followed by drying and rolling.
  • the negative electrode current collector 50 is not particularly limited as long as it is conductive without causing chemical changes in the battery, and may be made of, for example, copper, gold, stainless steel, aluminum, nickel, titanium, fired carbon, copper, or stainless steel. Surface treatment with carbon, nickel, titanium, silver, etc., aluminum-cadmium alloy, etc. can be used.
  • the bonding power of the negative electrode active material can be strengthened by forming fine irregularities on the surface, and it can be used in various forms such as films, sheets, foils, nets, porous materials, foams, and non-woven fabrics.
  • the negative electrode current collector generally has a thickness of 3 ⁇ m to 500 ⁇ m.
  • the negative electrode active material layer 60 can suppress the volume expansion of the negative electrode active material described above, and it may be possible to implement a thin film negative electrode having excellent adhesion between the negative electrode active material particles 10 and high energy density.
  • the thickness of the negative active material layer 60 is 10 ⁇ m or more, 15 ⁇ m or more, 20 ⁇ m or more, 25 ⁇ m or more, 30 ⁇ m or more, 35 ⁇ m or more, 40 ⁇ m or less, 35 ⁇ m or less, 30 ⁇ m or less, 25 ⁇ m or less, 20 ⁇ m or less, 15 ⁇ m or less, Preferably, it is 20 ⁇ m or more, 25 ⁇ m or more, 35 ⁇ m or less, and 30 ⁇ m or less.
  • the present invention provides a lithium secondary battery including a negative electrode, a positive electrode, a separator interposed between the negative electrode and the positive electrode, and an electrolyte.
  • the cathode described above may be used as the cathode.
  • the lithium secondary battery of the present invention can be manufactured by injecting the non-aqueous electrolyte solution of the present invention into an electrode structure consisting of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode.
  • the positive electrode, negative electrode, and separator that make up the electrode structure can all be used as those commonly used in manufacturing lithium secondary batteries.
  • the positive electrode can be manufactured by coating a positive electrode active material slurry containing a positive electrode active material and optionally a binder, a conductive material, and a solvent on a positive electrode current collector, followed by drying and rolling.
  • the positive electrode current collector is not particularly limited as long as it is conductive without causing chemical changes in the battery.
  • stainless steel, aluminum, nickel, titanium, calcined carbon, or carbon on the surface of aluminum or stainless steel. , surface treated with nickel, titanium, silver, etc. can be used.
  • the positive electrode active material is a compound capable of reversible intercalation and deintercalation of lithium, and may specifically include a lithium composite metal oxide containing lithium and one or more metals such as cobalt, manganese, nickel, or aluminum. there is. More specifically, the lithium composite metal oxide is lithium-manganese-based oxide (for example, LiMnO 2 , LiMn 2 O 4 , etc.), lithium-cobalt-based oxide (for example, LiCoO 2 , etc.), lithium-nickel-based oxide. (e.g. LiNiO 2 etc.), lithium-nickel-manganese oxide (e.g.
  • the lithium composite metal oxide is LiCoO 2 , LiMnO 2 , LiNiO 2 , lithium nickel manganese cobalt oxide (for example, Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , Li(Ni 0.5 Mn 0.3 Co 0.2 )O 2 , or Li(Ni 0.8 Mn 0.1 Co 0.1 )O 2 etc.), or lithium nickel cobalt aluminum oxide (for example, Li(Ni 0.8 Co 0.15 Al 0.05 )O 2 etc.), etc.
  • the lithium composite metal oxide is Li(Ni 0.6 Mn 0.2 Co 0.2 )O 2 , Li (Ni 0.5 Mn 0.3 Co 0.2 )O 2 , Li(Ni 0.7 Mn 0.15 Co 0.15 )O 2 or Li(Ni 0.8 Mn 0.1 Co 0.1 )O
  • the positive electrode active material may be included in an amount of 80% to 99% by weight based on the total weight of each positive electrode mixture.
  • the binder is a component that assists in the bonding of the active material and the conductive material and the bonding to the current collector, and is usually added in an amount of 1% to 30% by weight based on the total weight of the positive electrode mixture.
  • binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, Examples include polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluorine rubber, and various copolymers.
  • the conductive material is typically added in an amount of 1% to 30% by weight based on the total weight of the positive electrode mixture.
  • conductive materials are not particularly limited as long as they have conductivity without causing chemical changes in the battery.
  • graphite Carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black
  • Conductive fibers such as carbon fiber and metal fiber
  • Metal powders such as carbon fluoride, aluminum, 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 may be used.
  • Specific examples of commercially available conductive materials include acetylene black (Chevron Chemical Company, Denka Singapore Private Limited, Gulf Oil Company products, etc.), Ketjenblack, and EC series. (from Armak Company), Vulcan XC-72 (from Cabot Company), and Super P (from Timcal).
  • the solvent may include an organic solvent such as NMP (N-methyl-2-pyrrolidone), and may be used in an amount that provides a desirable viscosity when including the positive electrode active material, and optionally a binder and a conductive material.
  • NMP N-methyl-2-pyrrolidone
  • the solid concentration including the positive electrode active material, and optionally the binder and the conductive material may be included such that the concentration is 50% by weight to 95% by weight, preferably 70% by weight to 90% by weight.
  • the separator separates the negative electrode and the positive electrode and provides a passage for lithium ions to move. It can be used without particular restrictions as long as it is normally used as a separator in a lithium secondary battery, and in particular, it has low resistance to ion movement in the electrolyte. It is desirable to have excellent resistance and electrolyte moisturizing ability.
  • porous polymer films for example, porous polymer films made of polyolefin polymers such as ethylene homopolymer, propylene homopolymer, ethylene/butene copolymer, ethylene/hexene copolymer, and ethylene/methacrylate copolymer, or these. A laminated structure of two or more layers may be used.
  • porous non-woven fabrics for example, non-woven fabrics made of high melting point glass fibers, polyethylene terephthalate fibers, etc.
  • a coated separator containing a ceramic component or polymer material may be used to ensure heat resistance or mechanical strength, and may optionally be used in a single-layer or multi-layer structure.
  • electrolytes used in the present invention include organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel-type polymer electrolytes, solid inorganic electrolytes, and molten inorganic electrolytes that can be used in the production of lithium secondary batteries, and are limited to these. It doesn't work.
  • the electrolyte may include an organic solvent and a lithium salt.
  • the organic solvent may be used without particular limitation as long as it can serve as a medium through which ions involved in the electrochemical reaction of the battery can move.
  • the organic solvent includes ester solvents such as methyl acetate, ethyl acetate, gamma-butyrolactone, and ⁇ -caprolactone; Ether-based solvents such as dibutyl ether or tetrahydrofuran; Ketone-based solvents such as cyclohexanone; Aromatic hydrocarbon-based solvents such as benzene and fluorobenzene; Carbonate-based solvents such as dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); Alcohol-based solvents such as ethyl alcohol and isopropyl alcohol; nitriles such as R-CN (R is a C2 to C20 straight
  • carbonate-based solvents are preferable, and cyclic carbonates (e.g., ethylene carbonate or propylene carbonate, etc.) with high ionic conductivity and high dielectric constant that can improve the charge/discharge performance of the battery, and low-viscosity linear carbonate-based compounds ( For example, ethylmethyl carbonate, dimethyl carbonate, diethyl carbonate, etc.) are more preferable.
  • cyclic carbonates e.g., ethylene carbonate or propylene carbonate, etc.
  • low-viscosity linear carbonate-based compounds For example, ethylmethyl carbonate, dimethyl carbonate, diethyl carbonate, etc.
  • excellent electrolyte performance can be obtained by mixing cyclic carbonate and chain carbonate in a volume ratio of about 1:1 to about 1:9.
  • the lithium salt can be used without particular restrictions as long as it is a compound that can provide lithium ions used in lithium secondary batteries.
  • the lithium salt is LiPF6, LiClO 4 , LiAsF6, LiBF 4 , LiSbF 6 , LiAlO 4 , LiAlCl 4 , LiCF 3 SO 3 , LiC 4 F 9 SO 3 , LiN(C 2 F 5 SO 3 ) 2 , LiN (C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , LiCl, LiI, or LiB(C 2 O 4 ) 2 may be used.
  • the concentration of the lithium salt is preferably used within the range of 0.1 to 2.0M. When the concentration of lithium salt is within the above range, the electrolyte has appropriate conductivity and viscosity, so excellent electrolyte performance can be achieved and lithium ions can move effectively.
  • the electrolyte includes, for example, haloalkylene carbonate-based compounds such as difluoroethylene carbonate, pyridine, and trifluoroethylene for the purpose of improving battery life characteristics, suppressing battery capacity reduction, and improving battery discharge capacity.
  • haloalkylene carbonate-based compounds such as difluoroethylene carbonate, pyridine, and trifluoroethylene
  • One or more additives such as zolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxy ethanol, or aluminum trichloride may be further included. At this time, the additive may be included in an amount of 0.1% to 5% by weight based on the total weight of the electrolyte.
  • the lithium secondary battery according to the present invention stably exhibits excellent discharge capacity, output characteristics, and capacity maintenance rate, and is therefore widely used in portable devices such as mobile phones, laptop computers, digital cameras, and hybrid electric vehicles (HEV). ), etc., and is useful in the field of electric vehicles, etc., and can be particularly preferably used as a component battery of medium to large-sized battery modules. Accordingly, the present invention also provides a medium to large-sized battery module including the above secondary battery as a unit cell.
  • medium-to-large battery modules can be preferably applied to power sources that require high output and large capacity, such as electric vehicles, hybrid electric vehicles, and power storage devices.
  • a coating solution was prepared by adding 2 parts by weight of an aqueous binder to 500 parts by weight of water and stirring. The coating solution was sprayed onto 100 parts by weight of the negative electrode active material, and then dried in a vacuum oven at 120°C for 10 hours to prepare negative electrode active material particles coated with an aqueous binder.
  • PAA MW 3.5 million g/mol, average particle size (D50) 0.5 ⁇ m
  • PVA MW 3 million g/mol, average particle size (D50) 0.4 ⁇ m
  • the average particle diameter (D50) of the negative electrode active material was 2.5 ⁇ m.
  • a slurry composition was prepared by adding the negative electrode active material particles prepared above, carbon black (product name: Super C65, manufacturer: Timcal) as a conductive material, and a binder as a solvent for forming a negative electrode slurry at a weight ratio of 80:10:10 to distilled water.
  • the negative electrode slurry is coated on one side of a copper current collector (thickness: 8 ⁇ m) as a negative electrode current collector, rolled, and dried in a vacuum oven at 130°C for 10 hours to form a negative electrode active material layer, which is used as a negative electrode. did.
  • Li metal was used as a counter electrode, and a polyolefin separator was interposed between each cathode prepared above and Li metal, and then ethylene carbonate (EC) and diethyl carbonate (DEC) were added at a volume ratio of 30:70.
  • Coin-type half-cells were manufactured by injecting an electrolyte containing 1% by weight of vinylene carbonate (VC), 12.5% by weight of fluoroethylene carbonate (FEC), and 1M LiPF 6 dissolved in the mixed solvent.
  • Dispersibility More than half of the prepared negative electrode slurry was placed in a 40ml vial container and changes over time were measured. At this time, if the sedimentation rate is fast, the dispersibility is low, and if the sedimentation rate is high, the dispersibility is good.
  • Capacity maintenance rate at 50 cycles (%): The capacity retention rate at 50 cycles is defined by the following equation (1).
  • Capacity maintenance rate (%) Discharge capacity in 50 cycles / Discharge capacity in 1 cycle
  • Equation 2 The charge/discharge efficiency at 50 cycles is defined by Equation 2.
  • Charge/discharge efficiency (%) Discharge capacity in 50 cycles / Charge capacity in 50 cycles
  • Expansion rate (%) Thickness of anode mixture after charging / Thickness of anode mixture before charging
  • the composition was performed using the composition shown in Table 1 below, and the results are shown.
  • the secondary battery using the negative active material particles manufactured by the MF dry coating method had superior dispersibility and showed excellent results in battery characteristics compared to Comparative Examples 2 and 3, which were wet coating methods.
  • Comparative Examples 2 and 3 which were wet coating methods.
  • the expansion rates it can be seen that when dry coating is performed, the volume expansion of the battery is effectively suppressed due to the use of water-based polymers, PAA and PVA.
  • the composition was performed using the composition shown in Table 2 below, and the results are shown. At this time, all coatings of the negative electrode active material particles were performed using the MF dry method.

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  • Inorganic Chemistry (AREA)

Abstract

L'invention concerne un matériau actif d'anode, et une anode et une batterie secondaire au lithium le comprenant. Le matériau actif d'anode est revêtu d'un polymère à base d'eau de poids moléculaire élevé de telle sorte qu'une expansion de volume se produisant pendant la charge et la décharge d'une batterie secondaire au lithium est supprimée pour améliorer les caractéristiques de charge et de décharge et les caractéristiques de durée de vie de cycle à haut débit de la batterie.
PCT/KR2022/016876 2022-10-21 2022-11-01 Matériau actif d'anode, et anode et batterie secondaire au lithium le comprenant WO2024085297A1 (fr)

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Families Citing this family (1)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150027093A (ko) * 2012-05-25 2015-03-11 넥세온 엘티디 복합 입자
KR20180013105A (ko) * 2016-07-28 2018-02-07 삼성에스디아이 주식회사 리튬 이차 전지용 음극 및 이를 포함하는 리튬 이차 전지
KR20180033485A (ko) * 2018-03-23 2018-04-03 주식회사 엘지화학 표면 코팅된 다공성 실리콘계 음극 활물질 및 이의 제조방법
KR20190060698A (ko) * 2017-11-24 2019-06-03 주식회사 엘지화학 실리콘계 입자-고분자 복합체, 및 이를 포함하는 음극 활물질
KR20220008055A (ko) * 2020-07-13 2022-01-20 한국기계연구원 음극 활물질 및 이를 이용한 전극 제조방법

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101018659B1 (ko) 2008-03-19 2011-03-08 금호석유화학 주식회사 리튬 이차전지용 실리콘계 음극 활물질
KR102158221B1 (ko) 2018-07-31 2020-09-21 한국과학기술연구원 이차전지의 전극 활물질 표면에 전도성 고분자 코팅층을 균일하게 형성하는 방법
KR20200141318A (ko) 2019-06-10 2020-12-18 현대자동차주식회사 리튬이차전지용 음극 및 이를 포함하는 리튬이차전지
KR20210028920A (ko) 2019-09-05 2021-03-15 주식회사 아모그린텍 이차전지 음극 활물질용 중공형 입자, 이의 제조방법 및 이를 포함하는 이차전지
JP2021077487A (ja) 2019-11-06 2021-05-20 株式会社豊田自動織機 Ｓｉ含有負極活物質を含有する負極材料

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150027093A (ko) * 2012-05-25 2015-03-11 넥세온 엘티디 복합 입자
KR20180013105A (ko) * 2016-07-28 2018-02-07 삼성에스디아이 주식회사 리튬 이차 전지용 음극 및 이를 포함하는 리튬 이차 전지
KR20190060698A (ko) * 2017-11-24 2019-06-03 주식회사 엘지화학 실리콘계 입자-고분자 복합체, 및 이를 포함하는 음극 활물질
KR20180033485A (ko) * 2018-03-23 2018-04-03 주식회사 엘지화학 표면 코팅된 다공성 실리콘계 음극 활물질 및 이의 제조방법
KR20220008055A (ko) * 2020-07-13 2022-01-20 한국기계연구원 음극 활물질 및 이를 이용한 전극 제조방법

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