WO2017123029A1 - Matériau actif d'anode pour batterie secondaire au lithium et son procédé de préparation - Google Patents

Matériau actif d'anode pour batterie secondaire au lithium et son procédé de préparation Download PDF

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WO2017123029A1
WO2017123029A1 PCT/KR2017/000436 KR2017000436W WO2017123029A1 WO 2017123029 A1 WO2017123029 A1 WO 2017123029A1 KR 2017000436 W KR2017000436 W KR 2017000436W WO 2017123029 A1 WO2017123029 A1 WO 2017123029A1
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lithium secondary
active material
graphite
secondary battery
negative electrode
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English (en)
Korean (ko)
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신선영
이수민
채오병
김은경
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LG Chem Ltd
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LG Chem Ltd
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Priority claimed from KR1020170005388A external-priority patent/KR101961365B1/ko
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Priority to US15/748,747 priority Critical patent/US10604410B2/en
Publication of WO2017123029A1 publication Critical patent/WO2017123029A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D15/00—Lithium compounds
    • C01D15/08—Carbonates; Bicarbonates
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
    • C01D7/00—Carbonates of sodium, potassium or alkali metals in general
    • 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
    • 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
    • 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 for a lithium secondary battery and a method for manufacturing the same, and more particularly, to a negative electrode active material for a lithium secondary battery including graphite having an alkali carbonate layer formed on its surface.
  • a lithium secondary battery generally includes a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, a separator, and an electrolyte, and is a secondary battery in which charge and discharge are performed by intercalation-decalation of lithium ions.
  • Lithium secondary batteries have high energy density, high electromotive force, and high capacity, and thus have been applied to various fields.
  • Metal oxides such as LiCoO 2 , LiMnO 2 , LiMn 2 O 4, or LiCrO 2 are used as the positive electrode active material constituting the positive electrode of the lithium secondary battery, and metal lithium, graphite (graphite) ), Or carbon-based materials such as activated carbon, or materials such as silicon oxide (SiO x ) are used.
  • metal lithium was initially used, but as the charge and discharge cycles progress, lithium atoms grow on the surface of the metal lithium to damage the separator and damage the battery. Recently, carbon-based materials are mainly used.
  • the problem to be solved of the present invention is to provide a negative electrode active material for a lithium secondary battery that can solve the problem caused by the side reaction between the graphite-based active material and propylene carbonate.
  • Another object of the present invention is to provide a negative electrode active material for a lithium secondary battery and a method of manufacturing the same.
  • the graphite provides a Raman spectrometry (Raman spectroscopy) I D / I G -band ratio (ratio) value of 0.05 to 0.3, negative active material from.
  • the negative electrode active material for a lithium secondary battery of the present invention includes graphite having an alkali carbonate layer formed on its surface, the alkali carbonate layer contributes to forming a stable solid electrolyte (SEI) film, and includes propylene carbonate. Since the side reaction with the electrolyte is reduced, thereby improving the low temperature performance of the lithium secondary battery and improving the initial efficiency, it can be usefully used in the production of the lithium secondary battery.
  • SEI solid electrolyte
  • FIG. 2 is a view schematically showing a negative electrode including the negative electrode active material for a lithium secondary battery according to an example of the present invention.
  • FIG. 3 is a scanning electron microscope (SEM) photograph taken at different magnifications of graphite in which an alkali carbonate layer is formed on the surface prepared in Example 2.
  • SEM scanning electron microscope
  • Figure 4 is a graph showing the high temperature life evaluation results of the secondary battery manufactured using the negative electrodes prepared in Examples 3 and 4, and Comparative Examples 1 and 3.
  • the negative electrode active material for lithium secondary batteries of the present invention contains graphite having an alkali carbonate layer formed on its surface.
  • the alkali carbonate may be at least one selected from the group consisting of sodium carbonate (Na 2 CO 3 ), lithium carbonate (Li 2 CO 3 ), and potassium carbonate (K 2 CO 3 ).
  • the alkali carbonate layer is formed on the surface of the graphite and reacts with an electrolyte to form a more stable and solid solid electrolyte layer (SEI) on a negative electrode active material including graphite on which the alkali carbonate layer is formed.
  • SEI solid electrolyte coating
  • the solid electrolyte coating (SEI) may improve the initial efficiency of the lithium secondary battery including the same by suppressing side reactions between the graphite and propylene carbonate, which may be included in the electrolyte, and reduce the degree of self-discharge of lithium ions at high temperature and durability. Can improve.
  • the lithium secondary battery including the negative electrode active material containing graphite in which the alkali carbonate layer is formed restricts the propylene carbonate to the electrolyte. Because it can be used without, it can exhibit improved low temperature performance.
  • the alkali carbonate layer may have a thickness of 1 nm to 150 nm, specifically, may have a thickness of 10 nm to 130 nm, and more specifically, may have a thickness of 30 nm to 100 nm.
  • the thickness of the alkali carbonate layer is 1 nm or more, an appropriate degree of side reaction suppression effect of graphite and propylene carbonate due to the formation of the alkali carbonate layer may be expected, and when the thickness of the alkali carbonate layer is 150 nm or less, Alkali carbonate can be prevented from excessively lowering the electrical conductivity between the graphites.
  • the alkali carbonate layer may be 1% by weight to 5% by weight, specifically 2% by weight to 3% by weight, based on the total weight of the graphite on which the alkali carbonate layer is formed on the surface.
  • the alkali carbonate layer is formed to an appropriate degree to form the alkali carbonate layer. It can be expected that the appropriate degree of suppression of side reaction between the graphite and propylene carbonate, if the weight is less than 5% by weight, the thickness of the alkali carbonate layer is too thick, or the alkali carbonate layer is electrically conductive between the graphite, that is, one Excessive formation can be prevented so as to interfere with the electrical conduction between the graphite particles and other graphite particles in the surroundings.
  • the graphite may have a particle shape, and the alkali carbonate layer may cover the particle surface of the graphite.
  • the alkali carbonate layer may be formed in an area corresponding to 10% to 50% of the total surface area of the graphite, specifically, may be formed in an area corresponding to 10% to 40%, more specifically It may be formed in an area corresponding to 20% to 30%.
  • the alkali carbonate layer When the alkali carbonate layer is formed at 10% or more of the total surface area of the graphite, the alkali carbonate layer covers an appropriate area of the surface of the graphite, thereby suppressing side reactions of graphite with propylene carbonate at an appropriate level.
  • the alkali carbonate layer When the alkali carbonate layer is formed to 50% or less of the total surface area of the graphite, the alkali carbonate layer may be prevented from interfering with electrical conduction between the graphites.
  • the graphite may have a particle diameter of 6 ⁇ m to 30 ⁇ m, specifically 8 ⁇ m to 25 ⁇ m, and more specifically 10 ⁇ m to 23 ⁇ m.
  • the graphite has an I D / I G band ratio value of 0.05 to 0.3 in Raman spectroscopy.
  • the anode active material for a lithium secondary battery of the present invention includes graphite having an alkali carbonate layer formed on its surface, and the graphite has an I D / I G band ratio value of 0.05 to Raman spectroscopy in Raman spectroscopy. 0.3.
  • the I D may be a peak value located near a wavelength of 1350 cm ⁇ 1
  • the I G may be a peak value located near a wavelength of 1580 cm ⁇ 1
  • the I D The / I G band ratio may be the intensity ratio of the peaks.
  • the I D / I G band ratio value may be 0.05 to 0.3, specifically 0.1 to 0.25, and more specifically 0.13 to 0.23.
  • the I D / I G band ratio value is less than 0.05, since it is a high quality carbon material having a very low content of defects or impurities, it is not suitable for use as a negative electrode active material of a lithium secondary battery.
  • graphite having an I D / I G band ratio value of more than 0.3 since the structure having a defect is too large or the crystallinity is poor, no side reaction or no side reaction occurs with an electrolyte solution containing propylene carbonate. Very few
  • the graphite may be a carbon material having a graphite structure, and specifically, may be crystalline carbon.
  • crystalline carbon natural graphite, high temperature graphitized natural graphite, kish graphite, pyrolytic carbon, liquid phase pitch based carbon fiber, carbon microspheres (meso-carbon) high temperature calcined carbon such as microbeads, mesophase pitches, and petroleum or coal tar pitch derived cokes.
  • the negative active material for the lithium secondary battery may be used alone or in combination with another negative electrode active material.
  • a carbon material such as amorphous carbon or a carbon composite, in which lithium ions which are commonly used may be occluded and released, lithium metal, silicon or tin may be used.
  • the negative electrode active material for a lithium secondary battery may be used in a lithium secondary battery, and thus the present invention provides a lithium secondary battery including the negative electrode active material for a lithium secondary battery.
  • the lithium secondary battery may include a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode.
  • the positive electrode can be prepared by conventional methods known in the art.
  • a slurry may be prepared by mixing and stirring a solvent, a binder, a conductive material, and a dispersant in a positive electrode active material, and then applying (coating) to a current collector of a metal material, compressing, and drying the positive electrode to prepare a positive electrode.
  • the current collector of the metal material is a metal having high conductivity, and is a metal to which the slurry of the positive electrode active material can easily adhere, and is particularly limited as long as it has high conductivity without causing chemical change in the battery in the voltage range of the battery.
  • surface treated with carbon, nickel, titanium, silver, or the like on the surface of stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel may be used.
  • fine unevenness may be formed on the surface of the current collector to increase the adhesion of the positive electrode active material.
  • the current collector may be used in various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric, and may have a thickness of 3 ⁇ m to 500 ⁇ m.
  • the solvent for forming the positive electrode includes an organic solvent such as NMP (N-methyl pyrrolidone), DMF (dimethyl formamide), acetone, dimethyl acetamide or water, and these solvents alone or in combination of two or more. Can be mixed and used. The amount of the solvent used is sufficient to dissolve and disperse the positive electrode active material, the binder, and the conductive material in consideration of the coating thickness of the slurry and the production yield.
  • NMP N-methyl pyrrolidone
  • DMF dimethyl formamide
  • acetone dimethyl acetamide or water
  • the binder may be polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride (polyvinylidenefluoride), polyacrylonitrile, polymethylmethacrylate, Polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM), Sulfonated EPDM, styrene butadiene rubber (SBR), fluorine rubber, poly acrylic acid and polymers whose hydrogen is substituted with Li, Na or Ca, or the like, or Various kinds of binder polymers such as various copolymers can be used.
  • PVDF-co-HFP polyvinylidene fluoride-hexafluoropropylene copolymer
  • the conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery.
  • Examples of the conductive material include graphite such as natural graphite and artificial graphite; Carbon blacks such as acetylene black, Ketjen black, channel black, farnes black, lamp black and thermal black; Conductive fibers such as carbon fibers and metal fibers; Conductive tubes such as carbon nanotubes; Metal powders such as fluorocarbon, aluminum and nickel powders; Conductive whiskers 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 conductive material may be used in an amount of 1 wt% to 20 wt% with respect to the total weight of the positive electrode slurry.
  • the dispersant may be an aqueous dispersant or an organic dispersant such as N-methyl-2-pyrrolidone.
  • the negative electrode may be prepared by a conventional method known in the art, for example, by mixing and stirring the negative electrode active material and additives such as a binder and a conductive material to prepare a negative electrode active material slurry, it is applied to a current collector and dried It can be produced by compression.
  • the solvent for forming the negative electrode includes an organic solvent such as NMP (N-methyl pyrrolidone), DMF (dimethyl formamide), acetone, dimethyl acetamide or water, and these solvents alone or in combination of two or more. Can be mixed and used. The amount of the solvent used is sufficient to dissolve and disperse the negative electrode active material, the binder, and the conductive material in consideration of the coating thickness of the slurry and the production yield.
  • NMP N-methyl pyrrolidone
  • DMF dimethyl formamide
  • acetone dimethyl acetamide or water
  • the binder may be used to bind the negative electrode active material particles to maintain the molded body, and is not particularly limited as long as it is a conventional binder used in preparing a slurry for the negative electrode active material.
  • the non-aqueous binder may be polyvinyl alcohol, carboxymethyl cellulose, or hydroxy.
  • Any one or a mixture of two or more selected from the group consisting of ronitrile-butadiene rubber, styrene-butadiene rubber and acrylic rubber can be used.
  • Aqueous binders are economical and environmentally friendly compared to non-aqueous binders, are harmless to the health of workers, and have excellent binding effects compared to non-aqueous binders.
  • Preferably styrene-butadiene rubber may be used.
  • the binder may be included in less than 10% by weight in the total weight of the slurry for the negative electrode active material, specifically, may be included in 0.1% by weight to 10% by weight. If the content of the binder is less than 0.1% by weight, the effect of using the binder is insignificant and undesirable. If the content of the binder is more than 10% by weight, the capacity per volume may decrease due to the decrease in the relative content of the active material due to the increase in the content of the binder. not.
  • the conductive material is not particularly limited as long as it has conductivity without causing chemical change in the battery.
  • Examples of the conductive material include graphite such as natural graphite and artificial graphite; Carbon blacks such as 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 whiskers such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Or conductive materials such as polyphenylene derivatives.
  • the conductive material may be used in an amount of 1% by weight to 9% by weight based on the total weight of the slurry for the negative electrode active material.
  • the negative electrode current collector used for the negative electrode according to an embodiment of the present invention may have a thickness of 3 ⁇ m to 500 ⁇ m.
  • the negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery.
  • Examples of the negative electrode current collector include copper, stainless steel, aluminum, nickel, titanium, calcined carbon, and carbon on the surface of copper or stainless steel. Surface-treated with nickel, titanium, silver, and the like, aluminum-cadmium alloy and the like can be used.
  • fine concavities and convexities may be formed on the surface to enhance the bonding strength of the negative electrode active material, and may be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics.
  • porous polymer films conventionally used as separators such as polyolefin-based polymers such as ethylene homopolymer, propylene homopolymer, ethylene-butene copolymer, ethylene-hexene copolymer and ethylene-methacrylate copolymer, etc.
  • the porous polymer film prepared by using a single or a lamination thereof may be used, or a conventional porous nonwoven fabric, such as a high melting point glass fiber, polyethylene terephthalate fiber, etc. may be used, but is not limited thereto.
  • organic solvent included in the electrolyte solution those conventionally used in the electrolyte for secondary batteries may be used without limitation, and typically propylene carbonate (PC), ethylene carbonate (ethylene carbonate, EC ), Diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylmethyl carbonate (EMC), methylpropyl carbonate, dipropyl carbonate, dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane , Vinylene carbonate, sulfolane, gamma-butyrolactone, propylene sulfite, tetrahydrofuran, any one selected from the group consisting of, or mixtures of two or more thereof may be representatively used.
  • PC propylene carbonate
  • EC ethylene carbonate
  • DEC Diethyl carbonate
  • DMC dimethyl carbonate
  • EMC ethylmethyl carbonate
  • methylpropyl carbonate dipropyl carbon
  • ethylene carbonate and propylene carbonate which are cyclic carbonates among the carbonate-based organic solvents, may be preferably used because they have high dielectric constants to dissociate lithium salts in the electrolyte, and may be preferably used in such cyclic carbonates.
  • a low viscosity, low dielectric constant linear carbonate such as ethyl carbonate is mixed and used in an appropriate ratio, an electrolyte having high electrical conductivity can be prepared, and thus it can be used more preferably.
  • the lithium secondary battery including the negative electrode active material for the lithium secondary battery of the present invention has excellent propylene carbonate resistance, including graphite having an alkali carbonate layer formed on the surface thereof, so that the lithium secondary battery can exhibit excellent low-temperature performance.
  • it may be one containing the propylene carbonate.
  • the electrolyte solution stored according to the present invention may further include additives such as an overcharge inhibitor included in a conventional electrolyte solution.
  • FIG. 2 is a view schematically showing a negative electrode including a negative active material for a lithium secondary battery according to an example of the present invention.
  • the negative electrode 100 including the negative active material for a lithium secondary battery according to an example of the present invention includes graphite 111 and an alkali carbonate 112 layer formed on a surface of the graphite 111.
  • a negative electrode active material layer 110 (only a part of which is shown) including a conductive material 113 and binders 114 and 115 for binding them is formed on the current collector 120.
  • the alkali carbonate 112 layer is formed on a part of the surface of the graphite 111, and contributes to the formation of a stable solid electrolyte film (SEI, not shown) on the surface of the negative electrode 100 through the reaction with the electrolyte.
  • SEI stable solid electrolyte film
  • the external shape of the lithium secondary battery of the present invention is not particularly limited, but may be cylindrical, square, pouch type, or coin type using a can.
  • the lithium secondary battery according to the present invention may not only be used in a battery cell used as a power source for a small device, but also preferably used as a unit battery in a medium-large battery module including a plurality of battery cells.
  • Preferred examples of the medium-to-large device include, but are not limited to, electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, and electric power storage systems.
  • the present invention provides a method for manufacturing the negative electrode active material for the lithium secondary battery.
  • the negative electrode active material for a lithium secondary battery includes (1) preparing graphite having an I D / I G band ratio value of 0.05 to 0.3 in Raman spectroscopy; (2) mixing and stirring the aqueous solution of graphite and alkali carbonate; (3) filtering out the stirred mixture under reduced pressure; And (4) drying the product obtained by the filtration in a vacuum oven at 60 ° C to 200 ° C.
  • the I D may be a peak value located near a wavelength of 1350 cm ⁇ 1
  • the I G may be a peak value located near a wavelength of 1580 cm ⁇ 1
  • the I D / I G band ratio may be a peak value of the peaks. May be an intensity ratio.
  • the I D / I G band ratio value may be 0.05 to 0.3, specifically 0.1 to 0.25, and more specifically 0.13 to 0.23.
  • the I D / I G band ratio value is less than 0.05, since it is a high quality carbon material having a very low content of defects or impurities, it is not suitable for use as a negative electrode active material of a lithium secondary battery.
  • graphite having an I D / I G band ratio value of more than 0.3 since the structure having a defect is too large or the crystallinity is poor, no side reaction or no side reaction occurs with an electrolyte solution containing propylene carbonate. Very few
  • the graphite may be a carbon material having a graphite structure, and specifically, may be crystalline carbon.
  • the crystalline carbon includes natural graphite, high temperature graphitized natural graphite, kish graphite, pyrolytic carbon, liquid phase pitch based carbon fiber, and carbon microspheres (meso-carbon microbeads). ), High temperature calcined carbon such as liquid phase pitches and petroleum or coal tar pitch derived cokes.
  • a layer of the alkali carbonate can be formed on the surface of the graphite.
  • the stirring speed may be 100 rpm to 1,200 rpm, specifically 100 rpm to 800 rpm, and more specifically 200 rpm to 500 rpm.
  • an alkali carbonate may be bonded to the surface of the graphite to form a layer of alkali carbonate on the surface of the graphite.
  • the stirring speed is 1,200 rpm or less, the surface of the graphite may be smooth. While the layer of alkali carbonate can be formed, the excessive stirring speed can prevent the graphite from being damaged by physical external force, causing peeling or deformation of the crystal structure.
  • the stirring may be performed for 30 minutes to 12 hours, specifically for 30 minutes to 6 hours, and more specifically for 1 hour to 3 hours.
  • the stirring time is too short, the formation of an alkali carbonate layer on the surface of the graphite may be insufficient, and when the stirring time is too long, a problem may occur due to evaporation of the aqueous alkali carbonate solution in the process. It is preferable that it consists in a time range.
  • the agitation may be performed in a temperature range of 20 ° C. to 60 ° C., specifically 25 ° C. to 45 ° C., and more specifically 25 ° C. to 35 ° C.
  • the stirring temperature is less than 20 °C the reaction rate of the surface of the graphite and the alkali carbonate is slow to be difficult to coat, if the stirring temperature exceeds 60 °C, the graphite is sufficiently in the aqueous alkali carbonate solution
  • the aqueous alkali carbonate solution may evaporate or change to a water vapor state before it is wet.
  • the alkali carbonate may be at least one selected from the group consisting of sodium carbonate (Na 2 CO 3 ), lithium carbonate (Li 2 CO 3 ), and potassium carbonate (K 2 CO 3 ).
  • the aqueous alkali carbonate solution may be in a concentration of 1% to 10% (w / v), specifically, in a concentration of 1% to 7% (w / v), and more specifically 2% to 5% (w / v). Concentration.
  • the concentration of the aqueous alkali carbonate is 1% (w / w) or more, the alkali carbonate is smoothly bonded to the surface of the graphite, it is possible to prevent the problem that the stirring time is too long, 10% (w / w ) Or less, it is possible to prevent the alkali carbonate layer from being excessively formed to lower the conductivity between the graphite.
  • the agitated mixture is filtered to collect a negative electrode active material for a lithium secondary battery in which a product, that is, the alkali carbonate, forms a layer on the graphite surface.
  • the filtration may be performed under reduced pressure.
  • a process of additionally washing the negative active material for a lithium secondary battery in which the obtained alkali carbonate forms a layer on the graphite surface is not performed using distilled water.
  • the collected product obtained by the filtration can be dried in a vacuum oven at 60 ° C to 200 ° C to prepare a negative electrode active material for a lithium secondary battery.
  • the drying time is not particularly limited, but may be made for 3 hours or more, specifically 6 hours to 24 hours.
  • the product obtained through the filtration was dried for 24 hours at a temperature of 100 °C using a vacuum oven to prepare a graphite having an alkali carbonate layer formed on the surface.
  • Example 1 Graphite having an alkali carbonate layer formed on the surface of Example 1 was used as a negative electrode active material, and super c65 (Timcal) as a conductive material and polyvinylidene (PVdF) as a binder were used as a solvent, N-methyl pyrrolidone ( NMP) was mixed to a weight ratio of 94: 1: 5 to prepare a uniform negative electrode active material slurry.
  • Imcal super c65
  • PVdF polyvinylidene
  • NMP N-methyl pyrrolidone
  • the prepared negative electrode active material slurry was coated on one surface of a copper current collector to a thickness of 65 ⁇ m, dried and rolled, and then punched to a predetermined size to prepare a negative electrode.
  • Li metal was used as a counter electrode, and a polyolefin separator was interposed between the negative electrode and the Li metal, and then ethylene carbonate (EC), propylene carbonate (PC), and ethyl methyl carbonate (EMC) were 20:10:70.
  • EC ethylene carbonate
  • PC propylene carbonate
  • EMC ethyl methyl carbonate
  • a coin-type half cell was prepared by injecting an electrolyte solution in which 1 M LiPF 6 was dissolved in a solvent mixed at a volume ratio of.
  • Each of the batteries prepared in Examples 3 and 4 and Comparative Examples 1 to 4 were charged at 25 ° C. with a constant current (CC) of 0.1 C until it became 0.005 V, and then charged with constant voltage (CV) to charge current The first charge was performed until it became 0.005 C (cut-off current). Thereafter, it was left for 20 minutes and discharged until it became 1.0 V with a constant current (CC) of 0.1 C. The efficiency at this time was measured and shown in Table 1 below.
  • CC constant current
  • CV constant voltage
  • NMP N-methyl-2-pyrrolidone
  • the mixture slurry was prepared.
  • the positive electrode mixture slurry was applied to a thin film of aluminum (Al), which is a positive electrode current collector having a thickness of about 20 ⁇ m, dried to prepare a positive electrode, and then subjected to roll press to prepare a positive electrode.
  • Al aluminum
  • the prepared battery was charged at 1 C up to 4.2 V / 38 mA under constant current / constant voltage (CC / CV) conditions at 45 ° C., then discharged at 1 C up to 2.5 V under constant current (CC) conditions, and the discharge capacity thereof was measured. It was. This was repeated 1 to 300 cycles, the results are shown in Figure 4 below.
  • the y-axis is normalized capacity
  • the x-axis is cycle number.
  • the lithium secondary battery of Comparative Example 2 used the same material as Comparative Example 1 as the negative electrode active material, but since the electrolyte solution does not contain propylene carbonate, Examples 3 and 4 of the present invention. It was confirmed that the initial efficiency equivalent to the represents. However, since the lithium secondary battery of Comparative Example 2 does not include propylene carbonate in the electrolyte, it was confirmed that the low temperature performance was relatively inferior.
  • the lithium secondary batteries of Comparative Examples 3 and 4 have a low side reaction between propylene carbonate and graphite using graphite having low crystallinity, and thus have a large difference from the lithium secondary batteries according to Examples 3 and 4 in terms of initial efficiency. Although it was not found, as can be seen in Figure 4 in terms of high temperature life characteristics it was confirmed that the inferior to the lithium secondary batteries according to Examples 3 and 4 of the present invention.

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  • Battery Electrode And Active Subsutance (AREA)

Abstract

La présente invention concerne un matériau actif d'anode pour une batterie secondaire au lithium, comprenant du graphite comportant une couche de carbonate d'alcali formée sur celui-ci, le graphite ayant une valeur de rapport de bande ID/IG de 0,05 à 0,3, mesurée par spectroscopie Raman, et un procédé de préparation de celui-ci. Étant donné que le matériau actif d'anode pour une batterie secondaire au lithium de la présente invention comprend du graphite comportant une couche de carbonate d'alcali formé sur celui-ci, la couche de carbonate d'alcali contribue à la formation d'un film d'interface d'électrolyte solide stable (SEI) afin de réduire les réactions secondaires avec une solution électrolytique contenant du carbonate de propylène, la batterie secondaire au lithium pouvant être amélioré en termes de performances à basse température et d'efficacité initiale. En conséquence, la présente invention peut être utile pour la fabrication de batteries secondaires au lithium.
PCT/KR2017/000436 2016-01-14 2017-01-13 Matériau actif d'anode pour batterie secondaire au lithium et son procédé de préparation Ceased WO2017123029A1 (fr)

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US15/748,747 US10604410B2 (en) 2016-01-14 2017-01-13 Negative electrode active material for lithium secondary battery and method of preparing the same

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KR20160004798 2016-01-14
KR10-2016-0004798 2016-01-14
KR10-2017-0005388 2017-01-12
KR1020170005388A KR101961365B1 (ko) 2016-01-14 2017-01-12 리튬 이차전지용 음극 활물질 및 제조방법

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20030075800A (ko) * 2002-03-20 2003-09-26 삼성에스디아이 주식회사 리튬 이차 전지용 음극 활물질
US20090290287A1 (en) * 1999-06-11 2009-11-26 Nanocorp, Inc. Asymmetric electrochemical supercapacitor and method of manufacture thereof
JP2014132555A (ja) * 2012-08-29 2014-07-17 Sumitomo Bakelite Co Ltd 負極材料、負極活物質、負極およびアルカリ金属イオン電池
KR20150143334A (ko) * 2014-06-13 2015-12-23 주식회사 엘지화학 음극 활물질 및 이의 제조방법

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090290287A1 (en) * 1999-06-11 2009-11-26 Nanocorp, Inc. Asymmetric electrochemical supercapacitor and method of manufacture thereof
KR20030075800A (ko) * 2002-03-20 2003-09-26 삼성에스디아이 주식회사 리튬 이차 전지용 음극 활물질
JP2014132555A (ja) * 2012-08-29 2014-07-17 Sumitomo Bakelite Co Ltd 負極材料、負極活物質、負極およびアルカリ金属イオン電池
KR20150143334A (ko) * 2014-06-13 2015-12-23 주식회사 엘지화학 음극 활물질 및 이의 제조방법

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
KOMABA, S.: "Alkali carbonate-coated graphite electrode for lithium-ion batteries", CARBON, vol. 46, no. 9, 2008, pages 1184 - 1193, XP022795415, DOI: doi:10.1016/j.carbon.2008.04.021 *

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