WO2019177409A1 - Secondary battery electrode, and method for producing same - Google Patents

Secondary battery electrode, and method for producing same Download PDF

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Publication number
WO2019177409A1
WO2019177409A1 PCT/KR2019/003006 KR2019003006W WO2019177409A1 WO 2019177409 A1 WO2019177409 A1 WO 2019177409A1 KR 2019003006 W KR2019003006 W KR 2019003006W WO 2019177409 A1 WO2019177409 A1 WO 2019177409A1
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WO
WIPO (PCT)
Prior art keywords
active material
electrode
secondary battery
film
manufacturing
Prior art date
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PCT/KR2019/003006
Other languages
French (fr)
Korean (ko)
Inventor
이종혁
윤덕영
강희경
Original Assignee
에스케이이노베이션 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Priority claimed from KR1020190029127A external-priority patent/KR20190109284A/en
Application filed by 에스케이이노베이션 주식회사 filed Critical 에스케이이노베이션 주식회사
Priority to EP19768601.7A priority Critical patent/EP3767711A4/en
Priority to CN201980014936.0A priority patent/CN111788722A/en
Priority to US16/980,615 priority patent/US20210020898A1/en
Priority to JP2020545111A priority patent/JP2021515963A/en
Publication of WO2019177409A1 publication Critical patent/WO2019177409A1/en

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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
    • 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
    • H01M4/04—Processes of manufacture in general
    • 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
    • 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
    • H01M4/139—Processes of manufacture
    • 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
    • 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 secondary battery electrode and a manufacturing method thereof.
  • nickel-metal hydride secondary batteries are mainly used as a power source of electric vehicles, but lithium secondary batteries have a higher power density (more than three times that of nickel-metal hydride secondary batteries), have a long cycle life, and have low self-discharge rates. Research into using the battery as the main power source of the electric vehicle has been actively conducted.
  • An object of the present invention is to provide a method for manufacturing a novel secondary battery electrode capable of high-loading, high mixture density.
  • Another object of the present invention is to provide a method for manufacturing a new secondary battery electrode capable of implementing a binder-free electrode, in which the active material layer does not contain a binder.
  • Another object of the present invention is to provide a method of manufacturing a new secondary battery electrode that can reduce the cost by a more simplified process and can mass-produce a uniform quality electrode.
  • Another object of the present invention is to provide an active material film capable of implementing a high-loading, high-density electrode, a secondary battery electrode including the same, and a secondary battery including the same.
  • a method of manufacturing an electrode for a secondary battery according to the present invention includes: cutting a bulk of an active material to prepare an active material film; And a binding step of integrating a current collector and the active material film.
  • the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention may further include a bulk manufacturing step of manufacturing an active material bulk using a raw material including a particulate electrode active material before cutting.
  • the electrode active material may be a negative electrode active material or a positive electrode active material.
  • the bulk of the active material may be free standing.
  • the active material bulk may be a molded or sintered body.
  • the bulk manufacturing step includes a molding step of manufacturing a molded body by compression molding the raw material; Or a sintering step of manufacturing a sintered body by heat-treating the molded body prepared in the molding step and the molding step.
  • the raw material may further include an additive selected from at least one of a binder, a conductive material, a carbon precursor, and a pore former.
  • the conductive material may include particles, fibers, nanostructures, or mixtures of one or two or more materials selected from conductive carbon, conductive polymers, and metals.
  • the conductive nanostructure may be selected from one or two or more from nanowires, nanotubes, nanoplates, nanoribbons, nanoparticles, and nanorods.
  • the carbon precursor may be selected from one or more of coke, pitch, thermosetting and thermoplastic resin.
  • the particulate particles are the core of the electrode active material; Shell of heterogeneous material; may be a core-shell structure.
  • the heterogeneous material may include a second electrode active material, a precursor of the second electrode active material, a conductive material, a binder, a carbon precursor, or a mixture thereof.
  • the raw material may contain two or more kinds of electrode active materials different in composition, crystal structure, particle shape, mechanical properties or physical properties.
  • the porosity of the active material film may be controlled by the porosity of the bulk of the active material.
  • the electrode active material in the active material bulk has an orientation, the orientation of the electrode active material in the active material film based on the thickness direction of the active material film by the cutting direction of the cutting step Can be controlled.
  • the binding step may include forming an adhesive layer on at least one surface of the surface of the current collector and the surface of the active material film; And laminating the current collector and the active material film to be in contact with the adhesive layer therebetween.
  • the binding step may include forming a metal film on one surface of the active material film.
  • the adhesive layer may be conductive.
  • the negative electrode active material is a graphite graphite; Non-graphitizable carbon; Natural graphite; Artificial graphite; Carbon nanotubes; Graphene; silicon; Sn alloys; Si alloys; Oxides of one or more elements selected from Sn, Si, Ti, Ni, Fe and Li; Or mixtures thereof.
  • the positive electrode active material is a lithium-metal oxide of a layered structure; Spinel structure lithium-metal oxides; Lithium-metal phosphate of olivine structure; Or mixtures thereof.
  • the active material may contain natural graphite, artificial graphite, or a mixture thereof.
  • the active material may include a plate shape or a flake shape.
  • the bulk manufacturing step by pressing the raw material containing the composite particles of the core-shell structure of the electrode active material core-carbon precursor shell with a particulate electrode active material Preparing a molded body; And pyrolyzing the carbon precursor of the shell with carbon by heat treating the molded body.
  • the bulk manufacturing step comprises the steps of preparing a molded body by press molding a raw material including a particulate electrode active material and a carbon precursor; And pyrolysing the carbon precursor to carbon by heat treating the molded body.
  • the molded body may be produced by one-way, two-way or isodirectional compression molding.
  • the step of surface treatment of at least one surface of the active material film may be further performed.
  • the surface treatment may include surface roughness control.
  • the present invention includes an electrode for secondary batteries manufactured by the above-described manufacturing method.
  • Lithium secondary battery (I) is a positive electrode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the electrode selected from at least one of the positive electrode and the negative electrode may include an active material film containing an electrode active material, a current collector, and an adhesive for attaching the active material film to the current collector.
  • Lithium secondary battery (II) according to another embodiment of the present invention is a positive electrode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the active material film included in the electrode selected from at least one of the positive electrode and the negative electrode may be a binder-free film containing no organic binder.
  • the active material film may be a free standing film.
  • the active material located on the surface of the active material film may be cut particles.
  • the active material film may be a cut film cut from a molded or sintered body containing the electrode active material.
  • the active material film may have an orientation of the electrode active material in the active material film based on the thickness direction of the active material film.
  • the active material film may be formed between the particle neck of the electrode active material.
  • the active material film may not contain an organic binder.
  • the active material film has an absolute value of the difference between the porosity in the surface region and the porosity in the central region based on the cross section in the thickness direction. Divided by 10% or less.
  • the active material film may further include one or more selected from pyrolytic carbon and a conductive material.
  • the apparent porosity of the active material film may be 10 to 45%.
  • the active material film may include pyrolytic carbon for binding the particles of the electrode active material and the particles of the electrode active material.
  • the adhesive may include a resin having a curing ability.
  • the adhesive may include a conductive component selected from at least one conductive resin, conductive particles, and conductive nanostructures.
  • the electrode active material may be a negative electrode active material or a positive electrode active material.
  • the present invention includes a lithium secondary battery module including the lithium secondary battery described above.
  • the present invention includes a device that is powered by the above-described lithium secondary battery.
  • the present invention includes an active material membrane for an electrolyte based secondary battery.
  • the active material film according to an aspect of the present invention is an active material film for a secondary battery provided with an electrolyte, and may be an active material film for a secondary battery containing an electrode active material and capable of free-standing.
  • the active material film according to another embodiment of the present invention is an active material film for a secondary battery provided with an electrolyte, and may be a binder-free active material film containing an electrode active material and not containing an organic binder.
  • the active material film according to the embodiment of the present invention may be in a state in which a neck formed between the electrode active material particles is formed.
  • the electrode active material in the active material film may have an orientation based on the thickness direction of the active material film.
  • the active material film according to an embodiment of the present invention may further include at least one selected from a conductive material and pyrolytic carbon.
  • a ratio obtained by dividing the absolute value of the difference between the porosity in the surface region and the porosity in the central region by the porosity in the central region may be 10% or less based on the thickness direction cross section.
  • the active material film according to one embodiment of the present invention may further include one or more selected from pyrolytic carbon and a conductive material.
  • the apparent porosity of the active material membrane may be 10 to 45%.
  • the present invention includes an electrolyte-based secondary battery electrode.
  • the secondary battery electrode according to the present invention is an electrolyte-based secondary battery electrode, and includes a binder-free active material film containing an electrode active material and no organic binder.
  • the secondary battery electrode according to the present invention is an electrolyte-based secondary battery electrode, and may be an electrode containing an electrode active material and having an active material film bound to at least one surface of a current collector by an adhesive.
  • the active material film may be a free standing film.
  • the active material film may further include one or more selected from a conductive material and pyrolytic carbon.
  • the active material film may be in a state in which a neck formed between particles of the electrode active material is formed.
  • the present invention includes a secondary battery including the electrode described above.
  • the secondary battery electrode is manufactured by an extremely simple process of cutting-attaching an active material bulk, process construction is easy and inexpensive, and precise and high process control is also achieved. Unnecessary, there is an advantage of excellent commerciality.
  • the method of manufacturing a secondary battery electrode according to an embodiment of the present invention based on the cut-attach process of the bulk of the active material, by applying a process of slicing (slicing) instead of the coating process by applying a slurry as in the conventional process
  • a process of slicing slicing
  • the conductive substrate is shaken according to the control of the drying air flow, or the thickness variation according to the drying conditions of the edge and the center during drying after coating under high loading conditions, and therefore subsequent rolling process
  • the method for manufacturing a secondary battery electrode according to an embodiment of the present invention as a large amount of active material film is prepared on the basis of a bulk, by a simple process called a cut-attach process, it is possible to mass-produce an electrode of extremely uniform quality And, there is an advantage that can be produced in a large amount of electrodes of extremely uniform quality.
  • an electrode for a secondary battery in the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, as the active material bulk, which is a free-standing molded body or a sintered body, is cut to prepare an active material film, a binder-free active material film may be prepared, and the thickness of the active material film There is no substantial restriction on the active material film in the form of a thick film is possible, there is an advantage that the production of an electrode having a high loading and high mixture density.
  • the method of manufacturing an electrode for a secondary battery is made of an active material itself, made of a conductive material and an active material, made of an active material and pyrolytic carbon, or made of an active material, a conductive material, and pyrolytic carbon.
  • the preparation of the active material bulk is possible.
  • the electrolyte solution can stably penetrate even if the thickness of the active material film is increased, so that the thickness of the film is substantially unlimited.
  • the particulate electrode active material in the bulk of the active material is highly filled or sintered with each other by the pressure or pressure and heat of the molding process, there is an advantage that it is possible to produce an electrode having a high loading and high mixture density.
  • the method for manufacturing a secondary battery electrode according to an embodiment of the present invention can control the orientation direction of the electrode active material particles in the film of the active material film in the cutting direction of the bulk of the active material, so that the improvement of the electrolyte impregnation rate, output characteristics, and rate characteristics is possible. have.
  • the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention has an advantage that an active pore network has a uniform (designed) open pore network regardless of its thickness, so that the electrolyte solution is uniformly and stably impregnated with the electrolyte.
  • the secondary battery may be a binder-free film containing no organic binder, which is an independent member, so that high loading and high mixture density may be easily formed, and high energy density battery design may be easily implemented.
  • a binder-free film containing no organic binder which is an independent member, so that high loading and high mixture density may be easily formed, and high energy density battery design may be easily implemented.
  • the secondary battery according to an embodiment of the present invention has an advantage of uniformly and stably impregnating an electrolyte solution (and lithium ions) even in the form of a thick thick film by an orientation of an active material film or a structure bound by an interparticle neck as an independent member. have.
  • FIG. 1 is a cross-sectional view showing a cross section of an active material bulk that is a molded article according to an embodiment of the present invention.
  • FIG. 2 is a view showing a process for producing an active material film by cutting the bulk of the active material according to an embodiment of the present invention
  • FIG. 3 is a view showing the binding state of two electrode active material particles adjacent to each other in the bulk of the active material is a sintered body, according to an embodiment of the present invention
  • FIG. 4 is a cross-sectional view showing a cross section of an active material film according to an embodiment of the present invention.
  • FIG. 5 is another cross-sectional view showing a cross section of an active material film according to an embodiment of the present invention.
  • FIG. 6 is a cross-sectional view showing a cross section of an electrode according to an embodiment of the present invention.
  • FIG. 8 is a scanning electron microscope photograph of an active material film prepared according to an embodiment of the present invention.
  • the active material bulk is a three-dimensionally independent three-dimensionally alone containing an electrode active material, which can maintain its own shape and support its own weight. It may refer to a three-dimensional solid state in a free-standing state.
  • the bulk may refer to a size having one dimension (width, length or width) exceeding at least the design thickness based on at least the design thickness of the active material layer of the desired electrode. More specifically, the bulk is at least 5 times, substantially 10 times or more based on the thickness of the active material region of the electrode to be manufactured, the size of the three-dimensional solid dimension along at least one axis based on three axes perpendicular to each other It may mean having a size. In addition, it may mean that each dimension of the three-dimensional solid body along each of the other two axes has a size corresponding to or larger than the width or length of the active material region of the electrode to be manufactured, but is not necessarily limited thereto.
  • bulk may refer to a three-dimensional solid body having a weight that exceeds at least the design weight based on the design weight of the active material layer of the desired electrode. More specifically, it may mean a three-dimensional solid having a weight of 10 times or more, substantially 50 times or more based on the design weight (weight of one active material layer of the intended electrode), but is not necessarily limited thereto.
  • a free-standable membrane is a membrane reference having a width of 1 cm, a length of 5 cm, and a thickness corresponding to the active material area design thickness of the secondary battery of interest, with a hollow center, a flat bottom, and flat bilateral pillars.
  • a method of manufacturing an electrode for a secondary battery according to the present invention includes: cutting a bulk of an active material to prepare an active material film; And a binding step of integrating a current collector and the active material film.
  • the method of manufacturing an electrode for a secondary battery may further include a bulk manufacturing step of manufacturing an active material bulk using a raw material including a particulate electrode active material before cutting. That is, a method of manufacturing a secondary battery electrode according to an embodiment of the present invention a) manufacturing a bulk of the active material (bulk) using a raw material containing a particulate electrode active material (bulk manufacturing step); b) cutting the bulk of the active material to prepare an active material film (cutting step); And c) integrating a current collector and the active material film (binding step).
  • the bulk of the active material may be a molded or sintered body.
  • step a) may include a molding step of manufacturing a molded article by compression molding a raw material.
  • a molding step of compression molding the raw material to produce a molded body a molding step of compression molding the raw material to produce a molded body;
  • the manufacturing method of the electrode according to the present invention deviates from the conventional slurry-based process of coating and pressing the slurry containing the active material in the current collector, bulking the active material using a raw material containing a particulate electrode active material After the preparation of the active material, the bulk of the active material may be cut to prepare an active material film corresponding to the active material layer on the current collector in a conventional slurry-based process, and an active material film prepared independently of the current collector may be bonded to the current collector to prepare an electrode.
  • Conventional electrode production methods such as slurry application, drying and rolling include the properties of the slurry itself, such as viscosity and dispersibility of the slurry in the fluidized state, the specific application method or the physical (mechanical) properties of the material contained in the slurry, and the drying conditions of the applied film. This directly affects the structure of the active material layer.
  • the manufacturing technique of the electrode using the active material slurry is highly dependent on the dynamic element, and as the structure of the active material layer is determined, precise control of the active material layer is very difficult in reality, and it is difficult to ensure structural uniformity in a large area. Furthermore, there is also a thickness constraint of the active material layer which can be produced by the coating process. In addition, when the thickness of the electrode needs to be increased, the drying time is increased in the drying process, so the process parameters such as the length of the drying furnace should be changed, and thus there is a problem in that a construction of a new process facility is required.
  • the method of manufacturing the electrode according to the present invention is not slurry-based, by cutting the bulk of the active material having a pre-designed material, pore structure and porosity to prepare an independent active material film, and then to produce the electrode by binding the prepared active material film to the current collector As a result, the structure of the active material film can be precisely and reproducibly controlled.
  • the electrode manufacturing method according to the present invention is capable of producing a large amount of the active material film by cutting the bulk of the active material, as the active material film is prepared on the basis of the solid bulk of the active material rather than a liquid-based slurry, a large amount of active material film of uniform quality There is an advantage to produce.
  • the electrode manufacturing method according to the present invention can be easily controlled by the simple method of controlling the thickness of the film cut from the bulk of the active material, the thickness of the active material region provided on the current collector.
  • the thickness of the active material region provided on the current collector is not substantially constrained as the pores through which the electrolyte and the like penetrate are kept uniform and constant.
  • the electrode is based on a highly multi-step process such as slurry mixing, coating, drying, pressing, and slitting. Are manufactured.
  • the electrode active material slurry is prepared by gradually increasing the concentration (solid content concentration) from a low concentration to a high concentration, it is difficult to control the slurry concentration in consideration of dispersion and sedimentation reduction characteristics. It's tricky.
  • the production process of the slurry such as the recovery device of the organic solvent must be provided separately, and the manufacturing process is complicated and the process equipment and management is difficult.
  • the manufacturing method of the electrode according to the present invention is not based on the slurry, and based on the bulk of the active material, the organic solvent recovery apparatus (step) is unnecessary or minimized, and the remarkably simple process of preparing, cutting and attaching the bulk of the active material
  • the manufacturing of the electrode is possible by the process, which can significantly reduce the cost for process equipment and management.
  • the pore structure is unintentionally collapsed during the rolling of the active material layer, there is a problem that it is difficult to substantially realize the high density and the maintenance of the pores at the same time.
  • the manufacturing method according to the present invention as the pore structure and the porosity of the bulk of the active material having a physically (mechanically) stable strength is still maintained in the cut film (active material film), both the densification and the maintenance of the pores impregnated with the electrolyte solution There is an advantage that can be implemented.
  • the pore structure of the active material membrane may be controlled by only adjusting the pore structure of the active material bulk, and the porosity of the active material membrane may be controlled by the porosity of the active material bulk.
  • Method of manufacturing an electrode according to an embodiment of the present invention is an electrode for an electrolyte-based secondary battery, advantageously an electrode for an electrolyte-based lithium secondary battery, more advantageously an anode; cathode; And a separator interposed between the anode and the cathode; And it may be a method for producing a lithium secondary battery electrode comprising an electrolyte solution.
  • one problem to be solved by the present invention is to provide a method of manufacturing an electrode capable of high-loading and / or high-mixing while allowing an electrolyte solution to penetrate smoothly in an electrode provided in a lithium secondary battery including an electrolyte solution.
  • the electrode manufacturing method according to an embodiment of the present invention may include a method of manufacturing a negative electrode or a method of manufacturing a positive electrode according to the type of electrode active material.
  • the manufacturing method of the electrode according to an example may correspond to the manufacturing method of the negative electrode.
  • the particulate electrode active material included in the raw material is a positive electrode active material
  • a method of manufacturing an electrode according to an example may correspond to a method of manufacturing a positive electrode. Therefore, the manufacturing method of the electrode according to the present invention should not be construed as being limited to the manufacturing method of the positive electrode or the negative electrode.
  • the step of preparing the active material bulk using a raw material containing a particulate electrode active material, the pre-standable active material using a raw material containing a particulate electrode active material It may be a step of preparing the bulk.
  • the preparation of the active material bulk may be a step in which the active material bulk is physically integrated from a raw material including a particulate electrode active material by pressure (for a molded article) or application of pressure and heat (for a sintered body).
  • the raw material may include a particulate electrode active material, and the particulate particles may be spherical, flake (flake), aggregated, amorphous, plate, rod, crystalline (crystalline form consisting of thermodynamically stable crystal faces), polyhedron or these It may be a mixed form of, but is not limited thereto.
  • the electrode active material contained in a raw material is 1 type of electrode active material; Or two or more electrode active materials having different compositions, crystal structures, particle shapes, mechanical properties, or physical properties.
  • the different crystal structures also include cases of homogeneous or more having different crystal structures in the same composition.
  • different particle shapes include meanings of different particle shapes of different materials as well as different particle shapes of one material. For example, there may be mentioned primary particles or crystalline particles of one material, secondary particles of the same material, and flake particles of the same material as spherical particles of one material. It is presented to assist, but is not limited to.
  • the mechanical properties may include one or more selected properties such as hardness, strength, toughness, and ductility
  • physical properties include one of electrical conductivity, thermal conductivity, thermal expansion rate, and specific gravity. It may include the characteristic selected above.
  • the electrode active material contained in the raw material may be a negative electrode active material, and the negative electrode active material may be used as long as it is a material commonly used for the negative electrode of the secondary battery.
  • the negative electrode active material is digraphitizable carbon; Non-graphitizable carbon; Natural graphite; Artificial graphite; Carbon nanotubes; Graphene; silicon; Sn alloys; Si alloys; Oxides of one or more elements selected from Sn, Si, Ti, Ni, Fe and Li (eg, Sn oxide, Si oxide, Ti oxide, Ni oxide, Fe oxide (FeO) and lithium-titanium oxide (LiTiO 2 , Li 4 Ti 5 O 12 ); or a mixture thereof, but is not limited thereto.
  • the electrode active material contained in the raw material may be a positive electrode active material
  • the positive electrode active material may be used as long as it is a material capable of reversible insertion / removal of ions (for example, lithium ions) involved in charging and discharging.
  • the electrode material used for the anode may be sufficient.
  • the cathode active material may be at least one selected from cobalt, manganese, nickel, and at least one of a composite oxide of lithium.
  • a composite oxide of lithium examples include the following compounds. Li x Mn 1 - y M y A 2 , LixMn 1 - y M y O 2 - z X z , Li x Mn 2 O 4 - z X z , Li x Mn 2 -y MyM ' z A 4 , Li x Co 1 - y M y A 2 , Li x Co 1 - y M y O 2 - z X z , Li x Ni 1 - y M y A 2 , Li x Ni 1 - y M y O 2 - z X z , Li x Ni 1 - y M y A 2 , Li x Ni 1 - y M y O 2 - z X z , Li x Ni 1
  • the positive electrode active material may be a lithium-metal oxide having a layered structure; Spinel structure lithium-metal oxides; Lithium-metal phosphate of olivine structure; Or mixtures thereof.
  • the phosphate-based material of the olivine structure may include LiMPO 4 (M is Fe, Co, Mn) and the like, but is not limited thereto.
  • particulate particles may include core-shell structured composite particles as well as particles such as primary particles (crystalline particles), aggregated particles (secondary particles), amorphous particles, spherical particles, flake particles, acicular particles, and the like. Can be.
  • the particulate particles are the core of the electrode active material; It may be a composite particle of the core-shell structure of the shell of the heterogeneous material, the heterogeneous material of the shell is the second electrode active material, the precursor of the electrode active material, the conductive material, the precursor of the conductive material, the binder (first binder) or a mixture thereof It may include.
  • the shell may include a precursor of an electrode active material or a precursor of a conductive material
  • the synthesis or conversion of the material may also be performed during the heat application process for bulking. That is, since the production of the conductive material or the electrode active material may be made in-situ during the bulking of the raw material by heat application, the core of the electrode active material; and the precursor of the electrode active material or the precursor of the conductive material; Composite particles of a shell of the same precursor can be used in particulate form.
  • the bulking of the raw material and the material conversion of the precursor may be simultaneously performed, but if necessary, a separate heat application may be performed before or after the bulking of the molding or sintering furnace.
  • the precursor of the electrode active material may be a precursor of an electrode active material that is the same as the core, or may be a precursor of an electrode active material different from the core (heterogeneous).
  • the shell of the composite particle may be a conductive material or a precursor of the conductive material.
  • the conductive material can be used as long as it is a material known as a conductive material that is commonly incorporated into the active material slurry in order to improve the electrical conductivity of the electrode active material layer.
  • Specific examples of the conductive material include carbon black, acetylene black, ketjen black, channel black, farnes black, lamp black, thermal black, carbon nanotubes, carbon fibers (including VGCF) and exfoliated graphite or these Conductive carbon bodies such as mixtures thereof, but is not limited thereto.
  • the precursor of the conductive material may be a material known as a carbon precursor.
  • the precursor of the conductive material may include a carbon precursor that is converted to carbon by pyrolysis.
  • the carbon precursor may be at least one selected from coke, pitch, thermosetting resin and thermoplastic resin.
  • the coke may include petroleum or coal tar pitch derived cokes, and the pitch may include petroleum pitch, coal pitch or mixtures thereof.
  • the pitch may include an isotropic pitch, mesophase pitch, or a mixture thereof.
  • the resin used as the carbon precursor may be a thermosetting resin, a thermoplastic resin or a mixture thereof.
  • the thermosetting resin may be an epoxy resin, a polyester resin, a phenol resin, an alkyd (unsaturated polyester) resin, a polyimide resin, a vinyl ester resin, a polyurethane resin, a polyisocyanurate resin, or a mixture thereof, and the like.
  • the resin is polyethylene resin, polypropylene resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polyethylene terephthalate resin, polyester resin, polystyrene resin, polymethyl methacrylate resin, polyvinyl chloride resin, ABS (Acrylonitrile Butadien Stylene) Resins, polyamide resins, polycarbonate resins, polyoxymethylene resins, acrylic resins, polyvinylsulfide resins, polyetheretherketone resins, polytetrafluoroethylene resins, or mixtures thereof, but are not limited thereto.
  • the insertion of ions (eg lithium ions) involved in charging and discharging may also occur in the carbon (pyrolysis carbon) converted from the carbon precursor, and furthermore, the carbon precursor is converted into carbon It may also serve to bind and bind the electrode active material in the form of particles.
  • the carbon precursor should not be construed as being limited only to the precursor of the conductive material, and may not be interpreted as a precursor of the binder and / or the electrode active material.
  • the binder may include an organic binder, and the organic binder may be a polymer commonly used for electrodes of lithium secondary batteries for binding between active materials and between an active material and a current collector.
  • the binder may be polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride-trichloroethylene copolymer, polymethyl methacrylate, polyacrylonitrile, polyvinyl Pyrrolidone, polyvinylacetate, polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cya Noethyl sucrose, pullulan, carboxyl methyl cellulose
  • the active material bulk contains a binder (organic binder) derived from the shell of the composite particles, or the shell of the composite particles.
  • the contained binder (organic binder) may contain carbon remaining after carbonization or pyrolysis.
  • the active material bulk manufacturing step by pressing the raw material containing the composite particles of the core-shell structure of the electrode active material core-carbon precursor shell with a particulate electrode active material to form a molded body Manufacturing step; And pyrolyzing the carbon precursor of the shell with carbon by heat-treating the molded body.
  • the electrode active material core may be a positive electrode active material or a negative electrode active material.
  • the raw material may further include an additive selected from at least one of a binder (second binder), a conductive material, a carbon precursor, and a pore-forming agent together with the above-mentioned particulate electrode active material.
  • the raw material when the raw material includes a binder, or when a more even and rapid mixing of materials is required, the raw material may further include a solvent for dissolving the binder (second binder) contained as an additive or a dispersion medium for dispersing the raw material.
  • the binder (second binder) contained in the raw material as an additive may be an aqueous organic binder and / or a non-aqueous organic binder used in a conventional secondary battery.
  • the non-aqueous binder is vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HEP), polyvinylidene fluoride (polyvinylidenefluoride), polyacrylonitrile, polymethyl methacrylate (polymethylmethacrylate) ), Polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM ), Sulfonated ethylene propylene terpolymer (EPDM), polytetrafluoroethylene (PTFE), polyvinylidene fluoride
  • the active material bulk may contain a binder added as an additive, or the binder added as an additive may contain carbon remaining after carbonization or pyrolysis.
  • the conductive material is not particularly limited as long as it can be generally used to improve the conductivity of the active material layer in the secondary battery field.
  • the particles may include particles, fibers, nanostructures, or mixtures thereof of one or more materials selected from conductive carbon, conductive polymers, and metals.
  • one or more materials selected from conductive carbon, conductive polymers, and metals include artificial graphite, natural graphite, soft carbon, hard carbon, carbon black, acetylene black, ketjen black, denka black, thermal black. , Channel black, aluminum, tin, bismuth, silicon, antimony, nickel, copper, titanium, vanadium, chromium, manganese, iron, cobalt, zinc, molybdenum, tungsten, silver, gold, lanthanum, ruthenium, platinum, iridium, titanium oxide , Zinc oxide, potassium titanate, carbon fluoride, polyaniline, polythiophene, polyacetylene, polypyrrole or combinations thereof.
  • the conductive material may be particles (including amorphous particles), plate, rod, wire (fiber), or a mixture thereof, of the aforementioned conductive material, and together with or in place of the conductive material described above. It may include nanostructures.
  • the nanostructures may be selected from one or two or more from nanowires, nanotubes, nanoplatelets, nanoribbons, nanoparticles and nanorods. Such nanostructures can ensure uniform and excellent electrical conductivity in all directions of the bulk of the active material (and active material film) by a network of nanostructures.
  • the conductive material serves to improve the electrical conductivity of the bulk of the active material and the active material film, and active material particles when melt bonding (including partial melting) of the conductive material occurs by a heat treatment process or a separate energy application process for producing a sintered body. It may also play the role of a binder that binds the liver.
  • Pore formers may be decomposed or dissolved away during bulking of the raw materials or after bulking.
  • the pore-forming agent can be used as long as the carbon yield is 40% or less, specifically, a polymer having a carbon yield of 1 to 20%.
  • the carbonization yield of the polymer may be a carbonization yield based on 900 °C carbonization conditions in the N 2 reducing gas atmosphere of 99.99% or more purity.
  • the pore-forming agent may be a polymer having a carbon yield of 40% or less, specifically, a carbon yield of 1-20%, and a content of fixed carbon in residual carbon of 99% by weight or more.
  • Specific examples of the pore-forming agent for forming residual pores in the bulk of the active material include, but are not limited to, polystyrene, polyvinyl alcohol, polyvinyl chloride, epoxy resin, phenol resin, polypropylene, or a mixture thereof.
  • the pore former may be spherical to fibrous, but is not limited thereto.
  • the carbon precursor contained in the raw material as an additive may include at least one selected from coke, pitch, thermosetting resin, and thermoplastic resin.
  • the coke may include petroleum or coal tar pitch derived cokes, and the pitch may include petroleum pitch, coal pitch or mixtures thereof.
  • the pitch may include an isotropic pitch, mesophase pitch, or a mixture thereof.
  • the resin used as the carbon precursor may be a thermosetting resin, a thermoplastic resin or a mixture thereof.
  • the thermosetting resin may be an epoxy resin, a polyester resin, a phenol resin, an alkyd (unsaturated polyester) resin, a polyimide resin, a vinyl ester resin, a polyurethane resin, a polyisocyanurate resin, or a mixture thereof, and the like.
  • the resin is polyethylene resin, polypropylene resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polyethylene terephthalate resin, polyester resin, polystyrene resin, polymethyl methacrylate resin, polyvinyl chloride resin, ABS (Acrylonitrile Butadien Stylene) Resins, polyamide resins, polycarbonate resins, polyoxymethylene resins, acrylic resins, polyvinylsulfide resins, polyetheretherketone resins, polytetrafluoroethylene resins, or mixtures thereof, but are not limited thereto.
  • the carbonization yield of the resin used as the carbon precursor may be 10% or more, specifically 30 to 90%, and more specifically 40 to 90%.
  • the carbon precursor when using a carbon-based resin precursor having a carbon yield of 40% or less, the carbon precursor may also serve as a pore-forming agent.
  • carbon (pyrolysis carbon) generated by pyrolysis of the carbon precursor may play a role of a conductive material and a binder binding between the active material, and may also play a role of an active material involved in charge and discharge reactions. .
  • pyrolytic carbon is not limited to carbon derived from a carbon precursor, but also includes residual carbon derived from an additive such as a pore-forming agent or an organic binder by a heat treatment for producing a sintered body or a heat treatment process performed independently if necessary.
  • an additive such as a pore-forming agent or an organic binder by a heat treatment for producing a sintered body or a heat treatment process performed independently if necessary.
  • the active material bulk manufacturing step may include pressing a raw material including a particulate electrode active material and a carbon precursor to prepare a molded article; And pyrolysing the carbon precursor to carbon by heat treating the molded body.
  • the electrode active material core may be a positive electrode active material or a negative electrode active material.
  • the type and content of the additive contained in the raw material can of course be adjusted.
  • the raw material may contain 1 to 30 parts by weight, specifically, 1 to 20 parts by weight of the conductive material based on 100 parts by weight of the electrode active material, but is not limited thereto.
  • the raw material may contain 0.5 to 10 parts by weight of the binder based on 100 parts by weight of the electrode active material, but is not limited thereto.
  • the raw material may contain 1 to 30 parts by weight, specifically, 1 to 25 parts by weight of the carbon precursor based on 100 parts by weight of the electrode active material, but is not limited thereto.
  • the raw material may contain 1 to 20 parts by weight of the pore-forming agent based on 100 parts by weight of the electrode active material, but is not necessarily limited thereto.
  • the raw material may not contain a conductive material, a binder, a carbon precursor, and / or a pore-forming agent.
  • the bulk of the active material may be made of an electrode active material.
  • the raw material may further contain a dispersion medium for the solvent or dispersion of the binder to the carbon precursor, of course, the present invention is not limited by the use or the specific content of the solvent or dispersion medium.
  • a solvent or a dispersion medium may be used, and in the case of dry mixing, a solvent or a dispersion medium may not be used.
  • the solvent (aqueous solvent or organic solvent) contained in the raw material may be any aqueous solvent or organic solvent that is commonly used in the production of a positive electrode or negative electrode active material slurry in the secondary battery field.
  • the aqueous solvent may include a solvent including water, isopropyl alcohol, propanol, methanol, ethanol and the like
  • the organic solvent may be acetone, N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethyl Acetamide, chloroform, dichloromethane, trichloroethylene, normal hexane, N, N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran, or a mixed solvent thereof, and the like, but are not limited thereto.
  • the active material bulk may be a molded body manufactured by applying a physical force to the raw material, or may be a sintered body manufactured by applying heat to the molded body.
  • the molded body may be plastically deformed and bound to each other and have a constant strength
  • the sintered body may be bound to integral water by sintering and may have a constant strength
  • the active material bulk which is a molded or sintered body
  • the active material bulk may be a binder-free active material bulk containing no organic binder, and thus an active material film and a binder-free active material film may be prepared.
  • this is an example possible by the manufacturing method according to an embodiment of the present invention for producing an active material film which is a molded body or a sintered body and then cut it, and the present invention is a binder-free active material bulk binder-free active material film It is not limited to.
  • the step of preparing the active material bulk may be prepared by one-way, two-way, or isodirectional compression molding of the raw material.
  • the bulk manufacturing step of the active material, which is a molded body may include mixing raw materials; And pressing (compressing) molding the mixed raw materials.
  • the mixing of the raw materials may be dry or wet mixing. Dry mixing may be performed by mixing the particulate electrode active material with an additive such as a carbon precursor or the like without using a solvent (or a dispersion medium).
  • a solvent or a dispersion medium is used, but unlike a conventional active material slurry manufacturing process, the mixing is performed in a state where the solid content is very high (for example, solid content of 60% by weight or more, concrete weight of 70% by weight or more). It can be carried out, it is possible to significantly reduce the amount of the aqueous solvent to the organic solvent used as a solvent or a dispersion medium.
  • a drying step may be further carried out to volatilize the solvent (or dispersion medium) before or after molding.
  • Compression molding is performed by inserting a mixed raw material into a mold having an internal receiving space corresponding to a three-dimensional solid shape and size of a desired bulk, and then compressing the raw material by uniaxial pressing, biaxial pressing, or isostatic pressing. It can be performed by applying.
  • the pressure applied during molding may be properly adjusted in consideration of the type of material contained in the raw material, the sintering characteristics, and the designed porosity.
  • the molding may be performed at a pressure of 10 to 120 MPa, but is not limited thereto.
  • the active material bulk which is a molded article, may contain a material capable of plastically deforming the electrode active material, in particular, a negative electrode active material, substantially one or more carbon-based negative electrode active material selected from natural graphite and artificial graphite.
  • a material capable of plastically deforming the electrode active material in particular, a negative electrode active material, substantially one or more carbon-based negative electrode active material selected from natural graphite and artificial graphite.
  • the electrode active material is plastically deformed by compression and pressed in the pressure application direction, that is, its shape is deformed into pressed particles, and the orientation of the electrode active material is formed in the active material bulk by the pressed particles (electrode active material particles). Can be.
  • the orientation of the electrode active material is advantageous because it can improve the charge and discharge rate characteristics of the electrode.
  • the bulk of the active material is a molded article, it is preferable to prepare the molded article by uniaxial pressurization or biaxial pressurization after inputting the mixed raw material into the mold.
  • the present invention should not be construed as being limited only to the orientation caused by plastic deformation.
  • the orientation may be already formed in the process of adding and packing the raw material into the mold for molding and liquid kneading in the bulk manufacturing step. In this state, a magnetic field may be applied to control the orientation.
  • the flaky graphite-based active material may be oriented in a direction perpendicular to the compressive force for forming, and spherical natural graphite undergoes plastic deformation and It can be oriented in the vertical direction.
  • FIG. 1 is a material that can plastically deform an electrode active material, in particular, a carbon-based negative electrode active material, a molded body 200 manufactured by compression molding the raw material 100 containing the carbon-based negative electrode active material particles 110 before molding and It is a figure which shows the pressed particle 210 of the carbon-based negative electrode active material in the molded object 200.
  • the pressed particles 210 in which the carbon-based negative electrode active material particles 110 are deformed in a predetermined direction by compression molding may be formed, and the molded particles 200 may be formed by the pressed particles.
  • the orientation of the electrode active material particles (shown by the arrow in FIG. 1) may be formed.
  • the manufacturing method after the active material bulk is manufactured, according to the cutting direction for cutting the active material bulk having the orientation of the electrode active material, as the active material film is cut and attached to the current collector,
  • the orientation in the thickness direction of the active material film (the orientation direction of the electrode active material particles) can be controlled.
  • the orientation of such an electrode active material film is substantially difficult to realize in the conventional slurry-based electrode manufacturing technique of coating and rolling slurry. This is because when the plastic deformation (permanent deformation) of the active material occurs as the rolling is performed after the active material slurry is applied to the current collector, the orientation of the plastically deformed electrode active material particles is the interface direction between the current collector and the active material layer (active material). This is because it is limited to the direction parallel to the in-plane direction of the layer surface).
  • the thickness direction of the active material film 300 is referred to.
  • the orientation direction of the electrode active material may be controlled.
  • the active material film The thickness direction of 300 and the orientation direction of the active material particles (pressed particles) are substantially parallel, so that the impregnation of the electrolyte through the space between the particles and the particles and the diffusion of ions involved in charge and discharge, such as lithium ions, are more smoothly performed. Can be done.
  • the active material bulk may be a sintered body
  • an active material bulk which is a sintered body
  • the manufacturing method according to an embodiment of the present invention comprises the steps of preparing a molded body by putting the raw material into the mold and molding; Producing a sintered body by applying heat to the molded body; may include.
  • the molded article manufacturing step and the sintered body manufacturing step may be performed at the same time. That is, the sintered compact may be manufactured by simultaneously applying heat and physical force to the raw material.
  • Specific examples of applying mechanical force (physical force) together with heat include hot press sintering and the like.
  • the application of heat may be performed by heat treatment using a conventional furnace, but is not limited thereto, and may be performed using any method known to be used to manufacture a sintered body such as spark plasma sintering (SPS).
  • the atmosphere may be controlled in consideration of the type of the specific electrode active material during heat treatment (application of heat).
  • heat treatment may be performed in a non-oxidizing atmosphere such as nitrogen and argon.
  • the heat treatment may be performed in an oxygen-containing atmosphere such as an atmosphere. Can be performed.
  • the electrode active material of the raw material in the production of the active material bulk which is a sintered body may be a positive electrode active material or a negative electrode active material.
  • the electrode active material of the raw material may include a positive electrode active material or a non-carbon negative electrode active material.
  • the sintered body may be in a state in which grain boundaries or necks are formed between the electrode active material particles by heat application (specifically, for example, heat treatment) and the particulate electrode active material is integrally bound (fused).
  • the sintered compact may be in a state in which active material particles are bound to each other by pyrolysis carbon (pyrolysis carbon derived from a carbon precursor).
  • the active material bulk may be a sintered body in which electrode active material particles of a raw material form a neck and are bound to each other.
  • FIG. 3 illustrates active material particles 210 bound to each other by a neck (shown by an arrow in FIG. 3) based on two electrode active material particles 110 adjacent to each other in a raw material.
  • the sintering process is divided into an initial stage, a middle stage, and a final stage, and an initial stage of sintering is a stage in which a neck is formed between the particles.
  • the initial stage of sintering may correspond to a stage of sintering shrinkage of about 3-10% (vol%), specifically 3-7%.
  • the pores in the molded body are substantially mostly open pores, and mainly a mass transfer (diffusion) occurs at the contact point of the particles and the particles, and the particles and the particles are connected to each other by a neck. Accordingly, when the sintered body is a product of the initial stage of sintering in which the neck between the electrode active material particles is formed, it contains a large amount of open pores while having a mechanical (physical) strength that enables stable handling and process performance during cutting, conveying, and attaching processes.
  • the sintered body is not limited to the state connected to the neck between the electrode active material particles, and can not be interpreted.
  • heat to the molded body or the raw material specifically, thermal energy capable of moving a substance, and heat treatment of substantially 300 ° C. or more It can be interpreted as a product obtained by performing a heat treatment more substantially 500 ° C. or more and even more substantially 600 ° C. or more.
  • the negative electrode active material is a material that is difficult to plastically deform, such as hard carbon or soft carbon, or a material such as natural graphite that can be plastically changed if necessary, particulate electrode active material (hard carbon, soft carbon, natural graphite, etc.)
  • the bulk of the active material in the form of a sintered compact can be prepared by applying heat to convert the carbon precursor into carbon.
  • the sintered body may be in a state where particulate electrode active materials are bound by at least carbon (pyrolysis carbon) converted from a carbon precursor.
  • the active material bulk may include particulate active material and pyrolytic carbon binding the particulate active material
  • the active material film prepared from such active material bulk may also include pyrolytic carbon binding between the particulate active material and the electrode active material particles.
  • a free-standable sintered body may be manufactured by grain boundaries between electrode active material particles, neck formation, or binding by carbon (pyrolysis carbon) converted from a carbon precursor.
  • the active material bulk may be a binder-free sintered body, and the active material film prepared by cutting it may also be a binder-free film containing no binder.
  • the binder-free may be interpreted as containing no organic binder.
  • the weight loss rate is less than 2%, substantially less than 1%, and more substantially, It may mean that the weight loss does not occur within 0.5%, more substantially within the error range.
  • Carbon derived from the carbon precursor specifically, pyrolytic carbon may serve as a conductive material to improve conductivity, bind a particulate active material, and may also function as an active material capable of inserting lithium.
  • the binder-free may be interpreted as an organic binder-free
  • the binder-free active material bulk may mean a molded or sintered body containing no organic binder.
  • the binder-free sintered compact includes a sintered compact composed of an active material; A sintered body made of an active material and residual carbon (residual carbon by organic binder decomposition, etc.); A sintered body made of an active material and a conductive material; A sintered body composed of an active material, a conductive material and residual carbon; A sintered body made of an active material and carbon derived from a carbon precursor; A sintered body consisting of an active material, carbon precursor-derived carbon, and residual carbon; A sintered body made of an active material, a conductive material, and carbon derived from a carbon precursor; Or an sintered body made of an active material, a conductive material, carbon precursor-derived carbon, and residual carbon.
  • the active material film may be a binder-free film containing no organic binder.
  • the active material film that is a binder-free film may be made of an electrode active material, made of an electrode active material and a conductive material, or made of carbon which binds to the electrode active material.
  • the binder-free active material film can be manufactured by the manufacturing method structure of this invention, and if necessary, the active material film of this invention can contain an organic binder,
  • this invention is an active material film containing an organic binder, It should not be interpreted as excluding the bulk of the active material containing the organic binder.
  • the molded body before sintering may contain an organic binder, of course, the organic binder may be burned out during the sintering process and a binder-free sintered body may be manufactured.
  • the organic binder may or may not leave residual carbon depending on the process atmosphere during burn-out. If the process atmosphere is an oxidizing atmosphere, it may not leave residual carbon, and only serves to assist the active material particles to achieve physical integration before sintering.
  • the burnout atmosphere is a non-oxidizing atmosphere, the organic binder may serve to coat carbon on the surface of the active material particles or bind particles and particles with residual carbon while leaving residual carbon.
  • the raw material further contains an additive which is a binder together with the particulate electrode active material, an electrode active material which is hard to be plastically deformed, for example, a non-carbon-based negative electrode active material, a hard carbon or soft carbon, a positive electrode active material, and the like, and the active material bulk Of course it can also be prepared.
  • an electrode active material which is hard to be plastically deformed, for example, a non-carbon-based negative electrode active material, a hard carbon or soft carbon, a positive electrode active material, and the like, and the active material bulk Of course it can also be prepared.
  • the raw material further contains an additive which is a conductive material together with the particulate electrode active material
  • an additive which is a conductive material together with the particulate electrode active material
  • the bulk of the active material in which the conductive material is uniformly dispersed and contained, in particular, when the conductive material includes the nanostructure, the network of the nanostructure It is possible to manufacture the bulk of the active material in which the continuous current movement path is formed.
  • the conductive material contained in the bulk of the active material may be deformed, compressed, softened or partially melted by a pressure or pressure and heat applied for bulking, and may be in a state of being bound between the conductive materials and the electrode active material.
  • the particulate electrode active material is a composite particle having a core-shell structure
  • the composite particle itself may be used, and the core-shell structure may be used during the mixing of raw materials using the core particles (electrode active material particles) and the materials of the shell.
  • the composite particles can be made.
  • the electrode active material is a carbon-based negative electrode active material
  • the raw material including the core-shell composite particles of the carbon-based negative electrode active material core-carbon precursor shell is molded to prepare a molded body, and then the carbon precursor of the shell through heat treatment.
  • the bulk of the active material can be prepared by converting to carbon.
  • Bulk of the active material may be prepared by converting a carbon precursor in a state into carbon.
  • the carbon precursor may serve as a binder in the shaped body.
  • the active materials may be bound to each other and provide a conductive path, and the carbon-based active material bulk made of a carbon-based material may be advantageous.
  • the carbon-based active material bulk can be produced using low-cost plate-shaped graphite instead of expensive spherical graphite as the carbon-based electrode active material.
  • the flaky graphite is oriented in a direction parallel to the current collector by rolling, charging and discharging due to a phenomenon in which electrolyte impregnation becomes difficult or speed is slow in the direction perpendicular to the electrode There is a problem that the rate characteristic is lowered.
  • the flaky graphite in the electrode current collector can be adjusted to have the orientation in the vertical direction impregnated with the electrolyte This can be facilitated and the battery reaction speed can be improved.
  • the porosity can be adjusted by using a pore-forming agent and / or a common-coated structure, or by using a molding pressure or the like, while aligning, and thus, it is possible to solve problems in the use of conventional flaky graphite, which is commercially advantageous.
  • the pore-forming structure is a concept that is distinguished from the pore-forming agent, and is not plate-shaped, but is an active material particle having an average particle diameter of at least 1/2 or less than plate-graphite. When small, it may mean an active material which is located between the plate graphite particles and the surface of the particles to serve to space the surface and the surface. Specific examples are hard carbon, soft carbon, granulated artificial graphite, amorphous particle form If the well-known anode active material, such as artificial graphite, MCMB (mesocarbon microbead), spherical natural graphite, Li 4 Ti 5 O 12 is possible.
  • anode active material such as artificial graphite, MCMB (mesocarbon microbead), spherical natural graphite, Li 4 Ti 5 O 12 is possible.
  • the plate graphite is packed by pressure molding, whereby a molded article having an orientation in the particle unit can be produced.
  • the molding strength can be improved.
  • the heat treatment may convert the carbon-based precursor into carbon (pyrolysis) to improve the electrical conductivity of the bulk of the active material, and optionally, further convert the negative electrode active material by selectively performing a graphitization heat treatment.
  • the pyrolysis may be carried out under conventionally known conditions in consideration of the specific material of the carbon-based precursor, and the graphitization treatment may also be performed under the conventionally known conditions used for graphitizing carbon. For example, pyrolysis may be performed at a temperature of 600 to 1500 ° C., and graphitization may be performed at a temperature of 2800 ° C. or more, but is not limited thereto.
  • the manufacturing method comprises the steps of molding a raw material containing the active material and the carbon precursor, or a raw material containing the active material, the carbon precursor and the conductive material to produce a molded article; And heat-treating the molded body to produce a sintered body.
  • thermal decomposition of the carbon precursor may occur simultaneously during the heat treatment for sintering.
  • to heat the sintered body for more complete pyrolysis to prepare a secondary sintered body in which the carbon-based precursor is pyrolyzed into carbon may be further performed.
  • the step of heat-treating the sintered body or the secondary sintered body to produce a sintered body graphitized pyrolytic carbon may be further performed.
  • the apparent porosity of the bulk of the active material is a molded or sintered body may be 10 to 45%, specifically, may be 15 to 40%.
  • the apparent porosity of the active material film may be 10 to 45%, specifically 15 to 40%.
  • the active material film may have substantially the same porosity as the bulk of the active material.
  • the composition of the bulk of the active material (and the active material film) may vary depending on the type or content of the additive contained in the raw material.
  • the active material film may contain 1 to 30 parts by weight, specifically 1 to 20 parts by weight of the conductive material, based on 100 parts by weight of the electrode active material. It is not necessarily limited thereto.
  • the active material film may contain 0.5 to 30 parts by weight of pyrolyzed carbon, specifically, 1 to 25 parts by weight of pyrolyzed carbon based on 100 parts by weight of the electrode active material. However, it is not necessarily limited thereto.
  • a processing step of cutting and / or grinding the active material bulk may be further performed in order to process to a desired dimension such as chamfering or rectangular parallelepiped.
  • Cutting of the prepared active material bulk may be performed using a method commonly used to cut semiconductor ingots used for conventional semiconductor wafer manufacture, such as wire saws, laser cutting, and the like. It is not limited by the specific cutting method of an active material bulk.
  • the thickness of the active material film is controlled by the cutting width of the bulk of the active material, there is no limitation in the thickness of the active material film to be produced, and an active material film in the form of a thick film having a thickness of 200 ⁇ m or more, which is difficult to be produced by slurry coating technology, can also be easily manufactured.
  • the present invention is not limited by the thickness of the active material film, of course, the thickness of the active material film can be appropriately adjusted according to the use of the active material secondary battery.
  • the thickness of the active material film may range from several tens of micrometers order to several millimeters order, more specifically, 10 ⁇ m to 500 ⁇ m, but is not limited thereto.
  • FIG. 4 is a cross-sectional view of an active material film 300 prepared by cutting an active material bulk that is a molded body
  • FIG. 5 is a cross-sectional view of an active material film 300 prepared by cutting an active material bulk that is a sintered body.
  • the active material film or the bulk of the active material is made of the electrode active material is illustrated.
  • the active material bulk is an additive such as a conductive material, a carbon-based precursor and / or a binder, and the like. Of course, it may further include.
  • the active material located on the surface of the active material film may be cut particulates.
  • the cut surface of the cut particles may be parallel to the surface of the active material film 300.
  • the surface of the active material film 300 may include the cut surfaces of the cut particles.
  • the cut particulates refer to a shape of the electrode active material particles (inner particles) positioned at an inner center of the active material bulk, and the inner particles are cut along an arbitrary plane. can do.
  • the cut particulates are located at the inner center of the bulk of the active material, and the shape of the electrode active material particles (inner particles) in the state of being bound to each other is used as a reference, and the inside of the cut particles is formed along an arbitrary plane. It may mean a shape in which the particles are cut off.
  • the active material bulk is a sintered body, it is advantageous that the active material bulk is a sintered body at the initial stage of sintering in which a neck between electrode active material particles 110 contained as a raw material is formed.
  • the bulk of the active material when the bulk of the active material is a sintered body, it may mean a shape in which the electrode active material particles 110 contained in the raw material are cut along an arbitrary plane based on the shape of the electrode active material particles 110 contained in the raw material.
  • the cut particles In the cut-out shape based on the electrode active material particles contained as a raw material, the cut particles should not be interpreted strictly as cut particles of the electrode active material particles 110 contained as raw materials.
  • the concave curvature neck region may be properly considered in the cut shape. .
  • the manufacturing method further includes the step of surface treatment of at least one surface of the active material film after cutting the bulk of the active material to prepare the active material film and before integration or after the active material film and the current collector are integrated. can do.
  • Such surface treatment may include surface roughness control.
  • the surface treatment step may be a treatment of reducing the surface roughness of at least one surface of the active material film relative to the surface of the active material film before treatment, or a process of relatively increasing the surface roughness of at least one surface of the active material film, The surface roughness of one surface of the film may be reduced and the surface roughness of the other surface may be increased.
  • An example of a treatment for reducing surface roughness may be surface polishing, and one example of a treatment for increasing surface roughness may include surface etching, mechanical scratch, and the like.
  • the surface etching may include plasma etching, partial oxidation of the surface area when the active material film includes a carbon-based electrode active material, but the present invention is not limited thereto.
  • the surface roughness of the inorganic film or the carbon-based film may be increased or decreased. Any surface treatment method conventionally used for the purpose may be used.
  • a step (binding step) of integrating the current collector and the active material film may be performed.
  • integration may mean a state in which the current collector and the active material film are directly bound, or a state in which the current collector and the active material film are attached to each other.
  • a metal film may be directly formed on the active material film, thereby integrating the same.
  • the active material film is a film cut out of the active material bulk, specifically, the structure in which the film is free-standable, the active material film can act as a substrate (substrate).
  • the metal film may be any method conventionally used to form a conventional electrode or metal film, such as metal deposition (including chemical and physical vapor deposition), conductive ink application, and heat treatment.
  • the binding step may include: c1) forming an adhesive layer on at least one of the surface of the current collector and the surface of the active material film; And c2) laminating the current collector and the active material film to be in contact with each other with the adhesive layer therebetween.
  • the adhesive layer may be formed on one surface of the current collector, one surface of the active material film, or one surface of the current collector and one surface of the active material film.
  • the adhesive layer may be formed by applying an adhesive to at least one of the surface of the current collector and the surface of the active material film when the adhesive is a fluid phase.
  • the application of the adhesive may be carried out by an application method commonly used for the application of liquid or dispersion phases. For example, dip coating, spin coating, casting, bar coating, gravure coating, blade coating and roll coating, spray, Screen printing, inkjet printing, electrostatic printing, micro-contact printing, imprinting, gravure printing, offset-reverse offset printing, etc. can be performed by one or more application methods selected.
  • the coating may be performed by surface coating, line coating, point coating, etc.
  • the adhesive may be formed by attaching an adhesive film to at least one of the surface of the current collector and the surface of the active material film. At this time, the coating amount of the adhesive may be 0.1 to 1mg / cm 2 level, but is not limited thereto.
  • the active material film may be attached to the current collector by laminating the current collector and the active material film in contact with each other with the adhesive layer therebetween.
  • At least one of heat, light, and pressure may be applied when laminating the current collector and the active material film for uniform adhesion, curing of the adhesive, strengthening of the binding force, or rapid binding.
  • heat may be applied and pressure may be applied together with the heat.
  • hot pressing and the like may be used, and the pressure during hot pressing may be applied by pressing in a surface pressure method or a linear pressure method, but the present invention is not limited thereto.
  • the active material film may be bound to at least one surface of the current collector, that is, one surface of the current collector or each of two opposite surfaces of the current collector.
  • the active material film When the active material film is to be attached to each of two opposite surfaces of the current collector, the active material film is attached to one of two opposite surfaces of the current collector through steps c1) to c2), and then the other one of the two opposite surfaces.
  • the active material film may be attached to the active material film again through steps c1) to c2, and the active material film may be attached to each of two opposite surfaces of the current collector.
  • step c1) an adhesive layer is formed such that each of two opposing surfaces of the current collector contacts the active material film with the adhesive layer interposed therebetween, and in step c2), the adhesive layer and the active material film are stacked to form a sandwich structure around the current collector.
  • the active material film can be attached to each of two opposite surfaces of the current collector.
  • the active material film of the electrode may be a free-standing film, and may be a cut film cut from a molded body as shown in FIG. 4, or a cut film cut from a sintered body as shown in FIG. 5.
  • FIG. 6 is a cross-sectional view illustrating a cross section of an electrode, and includes an electrode active material 210 and conductive particles 220 on two opposite surfaces of the current collector 500 by an adhesive layer 400. It is a figure which shows the attached example.
  • the active material film 300 of FIG. 6 may be plastically deformed into a particle form in which the electrode active material which is plastically deformable is pressed by press molding and the orientation of the electrode active material particles are formed, or the electrode active material of the flake shape is press molded and packed in one direction. It is an example which shows the cut film cut
  • the active material film is a film in which a neck between electrode active material particles is formed, that is, a cut film cut from the sintered body of the initial sintering step, the surface pores opened by the continuous gap between the particles and the particles are similarly opened. And the pore channel across the thickness of the active material film is uniformly formed so that the electrolyte solution (and lithium ions) can penetrate stably and uniformly regardless of the thickness of the film.
  • the adhesive layer 400 may include a resin having curability.
  • having curability means the ability to lose fluidity and harden by chemical change, drying (volatile removal of solvent) or solidification.
  • the hardenability of the resin having a hardenability may include hardening by phase transformation (solidification) from a liquid phase (melted phase) to hard phase, hardening due to volatilization of the solvent, and / or hardening by chemical change.
  • the resin having a curing ability is one of a resin (resin solution), a thermoplastic resin (resin having a solidification ability by melting-solidification), a photocurable resin, a thermosetting resin, and a chemical curable resin in a state dissolved in a solvent. Or two or more selected resins.
  • the thermoplastic resin may be used in any known resin in which melting (or softening) occurs upon application to heat.
  • the thermoplastic resin may be a polyamide resin, a polyester resin (eg, an aromatic polyester resin such as polyethylene terephthalate), a polyacetal resin, a polycarbonate resin, a polyphenylene ether resin, or a polysulfide resin.
  • Polysulfone resin, polyether ketone resin, polyolefin resin, polystyrene resin and the like but is not limited thereto.
  • the thermoplastic resins may be used alone or in combination of two or more thereof.
  • the active material film may be bound to the current collector by melting (or softening) and cooling the thermoplastic resin by applying heat to a laminate laminated so that the current collector and the active material film are in contact with the adhesive layer therebetween. have. At this time, the pressure may be applied together with the heat to improve the binding force and to achieve a uniform binding.
  • the active material film may be bound to the current collector by laminating the current collector and the active material film so as to be in contact with each other with a coating film of the resin solution therebetween, and volatilizing removing the solvent of the resin solution.
  • the resin dissolved in the resin solution when using the resin solution may include the above-described binder material (aqueous binder and / or non-aqueous binder) as an example of the additive.
  • the adhesive layer may comprise a thermosetting, photocurable and / or chemically curable resin.
  • the adhesive layer may contain a thermosetting resin and / or a chemical curable resin.
  • thermosetting resin or the chemical curable resin may be any resin known to be thermally or chemically cured, and examples thereof include epoxy resins, unsaturated polyester resins, vinyl ester resins, acrylic resins, phenol resins, urea resins, melamine resins, aniline Resins, polyimide resins, bismaleimide resins, and the like, but are not limited thereto.
  • Curable resin may be used individually or in combination of 2 or more types.
  • the adhesive layer contains a thermosetting resin or a chemical curable resin, it is of course possible to further contain a curing agent or a curing accelerator known to be used for the resin.
  • the adhesive layer can be conductive or nonconductive.
  • the adhesive layer may include a non-conductive resin having the above-described hardenability.
  • the adhesive layer may include a conductive component selected from one or more of conductive resins, conductive particles, and conductive nanostructures.
  • a conductive component may be mixed with a resin solution or a resin melt and applied together with the resin.
  • the adhesive layer when the adhesive layer is conductive, the adhesive layer may include one or more components selected from conductive particles and conductive nanostructures, together with the non-conductive resin having the above-described hardenability.
  • the adhesive layer when the adhesive layer is conductive, the adhesive layer may include a conductive resin.
  • the conductive resin may have at least a curing ability (ie, curing by drying) according to the volatilization of the solvent, but is not limited thereto, and may have heat or chemical curing ability or solidify (phase transformation of melt-solidification) by a functional group. Of course, it may have a curing ability by.
  • the adhesive layer when the adhesive layer is conductive, the adhesive layer may include, together with the conductive resin, one or more components selected from conductive particles and conductive nanostructures.
  • the adhesive layer may include a resin matrix, and the resin matrix may be a conductive adhesive layer which is a conductive resin having curability.
  • the adhesive layer may include a resin matrix, and the resin matrix may be a non-conductive resin, and may be a conductive adhesive layer including a dispersed phase selected from the conductive particles and the conductive nanostructures, which are disposed in the resin matrix.
  • the conductive particles of the adhesive layer are one or more selected from conductive resin particles, particles of metal, coreshell particles of a nonconductive core-conductive shell (shell or metal shell of conductive resin) and coreshell particles of a conductive core-nonconductive shell. It may include particles, but is not limited thereto.
  • the conductive nanostructures of the adhesive layer may be metal nanowires such as silver nanowires; Conductive nanotubes such as carbon nanotubes; Metal nanoplates such as gold nanoplates and silver nanoplates; Two-dimensional carbon bodies such as graphene, metal nanorods such as silver nanorods, etc .; Or a mixture thereof, but is not limited thereto.
  • the conductive resin of the adhesive layer is polyacetylene, polypyrrole, PEDOT: PSS (poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate)), polyanilne, P3MT (poly (3-methylthiophene)), Or a mixed resin thereof, but is not limited thereto.
  • the conductive or non-conductive adhesive layer is a conventional non-conductive film (NCF; non-contuctive film), anisotropic conductive film (ACF) used for bonding in packaging fields, such as flip chip connection or chip mounting of conventional electronic components Film), a conductive film (CF) or a laminated film thereof; or an anisotropic conductive paste (ACP), a conductive paste (Conductive Paste) or a non-conductive paste (NCP) Membrane; but is not limited thereto.
  • NCF non-conductive film
  • ACF anisotropic conductive film
  • ACP anisotropic conductive paste
  • Conductive Paste Conductive Paste
  • NCP non-conductive paste
  • the current collector 500 is commonly used in the secondary battery field and may be used as long as it has a material having high conductivity without causing chemical change during battery operation.
  • the current collector may be copper, stainless steel, aluminum, nickel, titanium, calcined carbon, graphene, carbon nanotube, or carbon, nickel, titanium, silver, graphene, carbon nanotube on the surface of aluminum or stainless steel. And the like may be used as surface treated.
  • the current collector may be in the form of a foam, film, mesh, felt or porous film.
  • the current collector may have a surface irregularities formed on its surface. In the case of the current collector having the surface irregularities including the protruding structure, the binding area may increase, and the binding force between the active material film and the current collector may be increased, and charge transfer may occur more easily.
  • the present invention includes an electrode for secondary batteries manufactured by the above-described manufacturing method.
  • the secondary battery is an electrolyte-based secondary battery, specifically, a positive electrode; cathode; And a separator interposed between the anode and the cathode; And it may be a secondary battery containing an electrolyte.
  • the secondary battery includes a lithium secondary battery.
  • the present invention includes a lithium secondary battery including the secondary battery electrode manufactured by the above-described manufacturing method.
  • the secondary battery electrode manufactured by the above-described manufacturing method in the secondary battery may be a positive electrode, a negative electrode or a positive electrode and a negative electrode.
  • the present invention provides an electrode for a secondary battery.
  • the secondary battery electrode according to the present invention may include an active material film containing an electrode active material, a current collector and an adhesive for attaching the active material film to the current collector.
  • the electrode may have a structure of a current collector-adhesive layer (adhesive layer) -active material film, and the active material film may be an electrode bound to each side of the current collector or both sides of the current collector by an adhesive layer (adhesive layer).
  • the secondary battery electrode according to the present invention includes an active material film containing an electrode active material, and the active material film may be a binder-free film containing no organic binder.
  • the secondary battery electrode according to the present invention includes an active material film containing an electrode active material, the active material film may be a free standing film.
  • the secondary battery is an electrolyte-based secondary battery, specifically, a positive electrode; cathode; And a separator interposed between the anode and the cathode; And it may be a secondary battery including an electrolyte, the secondary battery includes a lithium secondary battery.
  • the active material film may have a uniform porosity in the thickness direction of the film, and the active material film has substantially the same porosity and pore structure regardless of the position in the thickness direction. Can be.
  • the porosity may be substantially the same between the surface area and the central area of the film based on the cross section of the active material film.
  • the uniform porosity is based on the cross section of the active material film, and the ratio of the difference between the porosity (P1) in the surface region and the porosity (P2) in the center region (the absolute value of P1-P2) divided by the porosity in the center region is 10%. Or less, substantially less than or equal to 8%, more substantially less than or equal to 5%, for example, substantially the same.
  • substantially identical means identical within a measurement error.
  • the porosity of the cross section of the active material film may be an area occupied by pores per unit area of the cross section of the thickness in the thickness cross section across the center of the active material film.
  • the surface area may mean an area up to 0.2t 0 from the surface based on the thickness (t 0 ) of the active material film, and the center area is based on the center (center line, virtual line of 0.5t 0 ) of the thickness cross section. This may mean an area up to 0.1t 0 (an area of 0.4t 0 to 0.6t 0 ) as the upper and lower portions, respectively.
  • the porosity of the surface region may refer to the porosity at each of the two surfaces as well as at any one of the two surfaces facing each other.
  • the porosity based on the thickness cross section can be calculated using a cross-sectional observation image such as a scanning electron microscope.
  • the electrode active material, the active material film or the current collector is similar to or the same as described above in the method of manufacturing a secondary battery electrode
  • the adhesive is the adhesive layer described in the method of manufacturing a secondary battery electrode Similar to the material of. Accordingly, the secondary battery electrode according to the present invention includes all the contents described in the above-described method for producing a secondary battery electrode.
  • the present invention includes a secondary battery, specifically, a lithium secondary battery including the secondary battery electrode.
  • the present invention includes a lithium secondary battery.
  • Lithium secondary battery according to the present invention is a positive electrode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the electrode selected from at least one of the positive electrode and the negative electrode may include an active material film containing an electrode active material attached to at least one surface of the current collector by an adhesive.
  • the positive electrode may be an active material film containing a positive electrode active material attached to at least one surface of the current collector by an adhesive. That is, a lithium secondary battery according to an embodiment of the present invention includes a positive electrode having an active material film containing a positive electrode active material attached to at least one surface of the current collector by an adhesive; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution.
  • the negative electrode may include a negative electrode active material layer positioned on the current collector, the negative electrode active material of the negative electrode active material layer may be a material commonly used for the negative electrode of a lithium secondary battery, and the negative electrode active material may be a lithium intercalable material. It is enough.
  • the negative electrode active material is lithium (metal lithium), digraphitizable carbon, non-graphitizable carbon, graphite, silicon, Sn alloy, Si alloy, Sn oxide, Si oxide, Ti oxide, Ni oxide, Fe oxide ( FeO) and lithium-titanium oxide (LiTiO 2 , Li 4 Ti 5 O 12 ) and the like may be one or more selected materials.
  • the negative electrode may be an active material film containing a negative electrode active material attached to at least one surface of the current collector by an adhesive. That is, a lithium secondary battery according to an embodiment of the present invention is a positive electrode; An anode in which an active material film containing an anode active material is attached to at least one surface of the current collector by an adhesive; And a separator interposed between the anode and the cathode; And an electrolyte solution.
  • the positive electrode may include a positive electrode active material layer positioned on the current collector, and the positive electrode active material of the positive electrode active material layer may be used as long as it is a material capable of reversible insertion / removal of lithium ions, and used for a positive electrode of a conventional lithium secondary battery.
  • Any electrode material may be used.
  • the cathode active material may be an oxide having a layer structure represented by LiCoO 2 , an oxide having a spinel structure represented by LiMn 2 O 4 , or a phosphate material having an olivine structure represented by LiFePO 4 .
  • a lithium secondary battery is a positive electrode having an active material film containing a positive electrode active material attached to at least one surface of the current collector by an adhesive; An anode in which an active material film containing an anode active material is attached to at least one surface of the current collector by an adhesive; A separator interposed between the positive electrode and the negative electrode; And an electrolyte solution.
  • the electrode active material, the active material film or the current collector is similar to or the same as described above in the method of manufacturing a secondary battery electrode
  • the adhesive is the adhesive layer described in the method of manufacturing a secondary battery electrode. Similar to the material of. Accordingly, the lithium secondary battery according to the present invention includes all the contents described in the above-described method for manufacturing the electrode for secondary batteries.
  • the separator may be a microporous membrane in which lithium ions are permeable in a conventional lithium secondary battery and electrically insulate the positive electrode and the negative electrode.
  • the separator is a porous polymer film, such as a porous polymer film made of a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ytterin / hexene copolymer and ethylene / methacrylate copolymer, etc. It may be a single or a laminate thereof, or a conventional porous nonwoven fabric, for example, a non-woven fabric of high melting glass fibers, polyethylene terephthalate fibers and the like can be used, but is not limited thereto.
  • the separator may serve to separate the positive electrode and the negative electrode by simply positioned between the positive electrode and the negative electrode as in a conventional lithium secondary battery.
  • the separator may be in a state of being bound (attached) to at least one electrode of the positive electrode and the negative electrode.
  • the electrolyte may be any conventional non-aqueous electrolyte that smoothly conducts ions involved in charging and discharging the battery in a conventional lithium secondary battery.
  • the non-aqueous electrolyte may include a non-aqueous solvent and a lithium salt.
  • the lithium salt contained in the electrolyte is a lithium cation and NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, ( CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, CF 3 CF 2 SO 3 -, (CF 3 SO 2) 2 N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 -, CH 3 CO 2 -, SCN -, and (CF 3 CF 2 SO 2) 2 N - providing an anion selected at least one from It may be a salt.
  • the solvent of the electrolyte is ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, vinylene carbonate, Dimethyl carbonate, diethyl carbonate, di (2,2,2-trifluoroethyl) carbonate, dipropyl carbonate, dibutyl carbonate, ethylmethyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, methylpropyl carbonate , Ethylpropyl carbonate, 2,2,2-trifluoroethyl propyl carbonate, methyl formate, ethyl formate, propyl formate, butyl formate, dimethyl ether, diethyl ether, di Propyl ether, methylethyl ether, methylpropyl ether, ethylpropyl ether, methyl acetate, ethyl acetate, prop
  • a lithium secondary battery may be manufactured by manufacturing an electrode assembly including a separator interposed between a positive electrode and a negative electrode, inserting the prepared electrode assembly into a case, and injecting and sealing an electrolyte. .
  • the electrode assembly impregnated in the electrolyte may be prepared by charging and sealing the case.
  • the battery case may be one commonly used in the lithium secondary battery field.
  • a cylindrical, square, pouch or coin type may be mentioned, but the present invention may not be limited by the spherical shape of the battery case.
  • the present invention includes the above-described secondary battery, for example, a lithium secondary battery as a unit battery cell, and a battery module in which unit battery cells are connected in series and / or in parallel.
  • the present invention includes a device that is powered by the above-described secondary battery, for example, a lithium secondary battery.
  • a lithium secondary battery for example, a lithium secondary battery.
  • Specific examples include, but are not limited to, electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, power storage systems, and the like.
  • FIG. 7 is an optical picture of observing an active material film (3cmx5cmx280 ⁇ m) prepared according to an embodiment of the present invention.
  • the active material film of FIG. 7 is manufactured by bulking an active material by molding and sintering, and then cut to a thickness of 280 ⁇ m using an electric saw.
  • molding is performed by putting a mixture of artificial graphite: pitch mixed at a weight ratio of 8: 2 into a molding mold and compressing the first molding, and then pressing the first molded article by cold isostatic pressing (CIP) secondarily. It became.
  • Sintering was carried out in a nitrogen-molded atmosphere of less than 50ppm oxygen temperature to 700 °C at 2 °C / min speed, the first heat treatment at 700 °C 60 minutes, and then again at 700 °C to 1200 °C 3 °C / min rate
  • Bulk active material was prepared by secondary heat treatment at 1200 ° C. for 60 minutes.
  • the apparent porosity of the prepared active material bulk and the active material film was substantially the same, and was 19.8%.
  • FIG. 8 (a) is a scanning electron microscope photograph of the surface of the prepared active material film
  • FIG. 8 (b) is a scanning electron microscope photograph of a thickness cross section of the prepared active material film.
  • the active material film is prepared by cutting the bulk of the active material having already uniform properties, it can be seen that the active material film has an open pore structure having substantially the same porosity in the surface and thickness cross-section of the active material film.
  • the pore area was measured by observing the surface area and the center area in the thickness cross section of the prepared active material film, it was confirmed that they had substantially the same porosity.
  • FIG. 9 is an optical photograph of a cathode obtained by attaching the active material films of FIGS. 7 and 8 to a Cu foil as a current collector.
  • the mirrored surface was attached to the current collector, and a copper paste (65 wt% of 30 nm copper nanoparticles and styrene-butadiene rubber 8) was used as a conductive adhesive. Weight percent)).
  • Table 1 summarizes the characteristics of the secondary battery manufactured using the negative electrode of FIG. 8.
  • Comparative Examples (1 and 2) were prepared using a conventional slurry method of coating, drying, and rolling a negative electrode slurry, using graphite as an active material and an organic binder / active material weight ratio (%) of 3.1.
  • graphite as an active material
  • organic binder / active material weight ratio (%) of 3.1 As a result of the secondary battery provided, it is an example produced by varying the thickness of the active material layer.
  • lithium metal (3.2cmx5.2cmx2mm) was used as the positive electrode, and the battery was formed between the negative electrode and the positive electrode plate through a separator (polyethylene, 25 ⁇ m thick), and the tab portion of the positive electrode and the tab portion of the negative electrode were Each was welded.
  • the welded anode / separator / cathode combination was placed in a pouch, and the tabbed portion was included in the sealing portion to seal three surfaces except the electrolyte injection surface. After pouring the electrolyte into the remaining part and sealing the remaining side, it was impregnated for 12 hours or more.
  • 1M LiPF 6 solution was used as a mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / diethylene carbonate (DEC) (25/45/30; volume ratio) as the electrolyte.

Abstract

A method for producing a secondary battery electrode, according to the present invention, comprises: a slicing step for producing an active material film by slicing an active material bulk; and a binding step for combining a current collector and the active material film. A method for producing a secondary battery electrode according to the present invention produces an active material film by slicing an active material bulk, which is a free-standing molded body or pellet, thus allowing binder-free active material film to be produced, and as no actual restrictions exist for the thickness of the active material film, thick active material film can be produced, and thus electrodes having high-loading and high composite density can be produced.

Description

이차전지용 전극 및 이의 제조방법Secondary Battery Electrode and Manufacturing Method Thereof
본 발명은 이차전지용 전극 및 이의 제조방법에 관한 것이다.The present invention relates to a secondary battery electrode and a manufacturing method thereof.
환경 규제 강화, 고유가, 및 화석 에너지의 고갈등으로 인해, 가솔린 차량, 디젤 차량 등 화석 연료를 사용하는 차량을 대체할 수 있는 전기자동차, 하이브리드 전기자동차에 대한 관심이 매우 높아지고 있다.Due to increased environmental regulations, high oil prices, and depletion of fossil energy, interest in electric vehicles and hybrid electric vehicles that can replace fossil fuel-based vehicles such as gasoline vehicles and diesel vehicles is increasing.
현재 전기자동차의 동력원으로 주로 니켈수소 금속 이차전지가 사용되고 있으나, 니켈수소 금속 이차전지 대비 높은 출력밀도(니켈수소 금속 이차전지 대비 3배 이상)를 가지고, 사이클 수명이 길며, 자기방전율이 낮은 리튬 이차전지를 전기자동차의 주 동력원으로 사용하고자 하는 연구가 활발히 진행되고 있다. Currently, nickel-metal hydride secondary batteries are mainly used as a power source of electric vehicles, but lithium secondary batteries have a higher power density (more than three times that of nickel-metal hydride secondary batteries), have a long cycle life, and have low self-discharge rates. Research into using the battery as the main power source of the electric vehicle has been actively conducted.
리튬 이차전지가 전기자동차의 동력원으로 사용되기 위해서는, 무엇보다 고용량이 구현되어야 하며, 이를 위해 고용량의 새로운 음극 활물질이나 양극 활물질(대한민국 등록특허 제1572082호 및 대한민국 등록특허 제1608635호)에 대한 기술 개발이 주를 이루고 있다.In order to use a lithium secondary battery as a power source of an electric vehicle, a high capacity must be implemented above all, and for this purpose, a technology development for a new high-capacity negative electrode active material or positive electrode active material (Korea Patent No. 15,208,208 and Korea Patent No. 1608635) is performed. This week.
그러나, 고용량의 새로운 물질 개발이 이루어진다 하더라도, 활물질, 결착제 및 도전재를 함유하는 슬러리를 집전체에 도포한 후 건조 및 압연하여 제조하는 종래의 전극 제조기술로는 고합제밀도로 제작시 공극이 막히면서 전해액 함침이 어려워져 리튬이온의 이동도가 저하되며, 압연에 의해 활물질이 집전체와 수평한 방향으로 눌려 리튬이온의 이동거리가 길어지며 경로의 복잡성이 증가 (tortuosity 증가)하는 문제로 인해 고합제, 고밀도 전극 구현에 그 한계가 있다.However, even if a new material with a high capacity is developed, conventional electrode manufacturing techniques for applying a slurry containing an active material, a binder, and a conductive material to a current collector, followed by drying and rolling, to produce voids when manufacturing at a high mixture density Moisture impregnated with electrolytes, which impedes the mobility of lithium ions and decreases the mobility of lithium ions.As the active material is pressed in a horizontal direction with the current collector by rolling, the movement distance of lithium ions increases and the complexity of the path increases (tortorosity increase). First, there is a limit to the high density electrode implementation.
본 발명의 목적은 고-로딩, 고합제 밀도 구현이 가능한 새로운 이차전지용 전극의 제조 방법을 제공하는 것이다.An object of the present invention is to provide a method for manufacturing a novel secondary battery electrode capable of high-loading, high mixture density.
본 발명의 다른 목적은 활물질층이 바인더를 함유하지 않는, 바인더-프리(binder-free) 전극의 구현이 가능한 새로운 이차전지용 전극의 제조방법을 제공하는 것이다.Another object of the present invention is to provide a method for manufacturing a new secondary battery electrode capable of implementing a binder-free electrode, in which the active material layer does not contain a binder.
본 발명의 다른 목적은 보다 단순화된 공정에 의해 비용 절감이 가능하며 균일한 품질의 전극을 대량 생산할 수 있는 새로운 이차전지용 전극의 제조방법을 제공하는 것이다.Another object of the present invention is to provide a method of manufacturing a new secondary battery electrode that can reduce the cost by a more simplified process and can mass-produce a uniform quality electrode.
본 발명의 다른 목적은 고-로딩, 고합제 밀도의 전극이 구현될 수 있는 활물질 막, 이를 포함하는이차전지용 전극 및 이를 포함하는 이차전지를 제공하는 것이다.Another object of the present invention is to provide an active material film capable of implementing a high-loading, high-density electrode, a secondary battery electrode including the same, and a secondary battery including the same.
본 발명에 따른 이차전지용 전극의 제조방법은 활물질 벌크를 절단하여 활물질 막을 제조하는 절단단계; 및 집전체와 상기 활물질 막을 일체화하는 결착단계;를 포함한다.A method of manufacturing an electrode for a secondary battery according to the present invention includes: cutting a bulk of an active material to prepare an active material film; And a binding step of integrating a current collector and the active material film.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은 절단 전, 입자상의 전극 활물질을 포함하는 원료를 이용하여 활물질 벌크(bulk)를 제조하는 벌크제조단계;를 더 포함할 수 있다.The method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention may further include a bulk manufacturing step of manufacturing an active material bulk using a raw material including a particulate electrode active material before cutting.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 전극 활물질은 음극 활물질 또는 양극 활물질일 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the electrode active material may be a negative electrode active material or a positive electrode active material.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 활물질 벌크는 프리 스탠딩 가능한 것일 수 있다. In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the bulk of the active material may be free standing.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 활물질 벌크는 성형체 또는 소결체일 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the active material bulk may be a molded or sintered body.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 벌크제조단계는 상기 원료를 압축 성형하여 성형체를 제조하는 성형 단계; 또는 상기 성형 단계와 성형 단계에서 제조된 성형체를 열처리하여 소결체를 제조하는 소결단계;를 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the bulk manufacturing step includes a molding step of manufacturing a molded body by compression molding the raw material; Or a sintering step of manufacturing a sintered body by heat-treating the molded body prepared in the molding step and the molding step.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 원료는 바인더, 도전재, 탄소 전구체 및 기공 형성제에서 하나 이상 선택되는 첨가제를 더 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the raw material may further include an additive selected from at least one of a binder, a conductive material, a carbon precursor, and a pore former.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 도전재는 전도성 탄소, 전도성 고분자 및 금속에서 하나 또는 둘 이상 선택된 물질의 입자, 섬유, 나노구조체 또는 이들의 혼합물을 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the conductive material may include particles, fibers, nanostructures, or mixtures of one or two or more materials selected from conductive carbon, conductive polymers, and metals.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 전도성 나노구조체는 나노와이어, 나노튜브, 나노판, 나노리본, 나노입자 및 나노막대에서 하나 또는 둘 이상 선택될 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the conductive nanostructure may be selected from one or two or more from nanowires, nanotubes, nanoplates, nanoribbons, nanoparticles, and nanorods.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 탄소 전구체는 코크스, 피치, 열경화성 및 열가소성 수지에서 하나 이상 선택될 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the carbon precursor may be selected from one or more of coke, pitch, thermosetting and thermoplastic resin.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 입자상의 입자는 전극 활물질의 코어; 이종 물질의 쉘;의 코어-쉘 구조일 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the particulate particles are the core of the electrode active material; Shell of heterogeneous material; may be a core-shell structure.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 이종 물질은 제2전극활물질, 제2전극활물질의 전구체, 전도성 물질, 바인더, 탄소 전구체 또는 이들의 혼합물을 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the heterogeneous material may include a second electrode active material, a precursor of the second electrode active material, a conductive material, a binder, a carbon precursor, or a mixture thereof.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 원료는 조성, 결정구조, 입자 형상, 기계적 특성 또는 물리적 특성이 상이한 2종류 이상의 전극 활물질을 함유할 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the raw material may contain two or more kinds of electrode active materials different in composition, crystal structure, particle shape, mechanical properties or physical properties.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 활물질 벌크의 기공률에 의해 활물질 막의 기공률이 제어될 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the porosity of the active material film may be controlled by the porosity of the bulk of the active material.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 활물질 벌크 내 전극 활물질은 배향성을 가지며, 절단단계의 절단 방향에 의해 활물질 막의 두께 방향을 기준한 활물질 막 내 전극 활물질의 배향 방향이 제어될 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the electrode active material in the active material bulk has an orientation, the orientation of the electrode active material in the active material film based on the thickness direction of the active material film by the cutting direction of the cutting step Can be controlled.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 결착단계는 집전체의 표면과 활물질 막의 표면 중 적어도 일 표면에 접착층을 형성하는 단계; 및 접착층을 사이에 두고 집전체와 활물질 막이 맞닿도록 적층하는 단계;를 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the binding step may include forming an adhesive layer on at least one surface of the surface of the current collector and the surface of the active material film; And laminating the current collector and the active material film to be in contact with the adhesive layer therebetween.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 상기 결착단계는 활물질 막의 일 표면에 금속 막을 형성하는 단계;를 포함할 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the binding step may include forming a metal film on one surface of the active material film.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 접착층은 전도성일 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the adhesive layer may be conductive.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 음극 활물질은 이흑연화성 탄소; 난흑연화성 탄소; 천연 흑연; 인조 흑연; 탄소나노튜브; 그래핀; 실리콘; Sn 합금; Si 합금; Sn, Si, Ti, Ni, Fe 및 Li에서 하나 또는 둘 이상 선택되는 원소의 산화물; 또는 이들의 혼합물;을 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the negative electrode active material is a graphite graphite; Non-graphitizable carbon; Natural graphite; Artificial graphite; Carbon nanotubes; Graphene; silicon; Sn alloys; Si alloys; Oxides of one or more elements selected from Sn, Si, Ti, Ni, Fe and Li; Or mixtures thereof.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 양극 활물질은 층상 구조의 리튬-금속 산화물; 스피넬 구조의 리튬-금속 산화물; 올리빈 구조의 리튬-금속 포스페이트; 또는 이들의 혼합물을 포함할 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the positive electrode active material is a lithium-metal oxide of a layered structure; Spinel structure lithium-metal oxides; Lithium-metal phosphate of olivine structure; Or mixtures thereof.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 활물질은 천연 흑연, 인조 흑연 또는 이들의 혼합물을 함유할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the active material may contain natural graphite, artificial graphite, or a mixture thereof.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 활물질은 판형 또는 플레이크 형상을 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the active material may include a plate shape or a flake shape.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 벌크제조단계는, 입자상의 전극 활물질로 전극 활물질 코어-탄소 전구체 쉘의 코어-쉘 구조의 복합 입자를 포함하는 원료를 가압 성형하여 성형체를 제조하는 단계; 및 상기 성형체를 열처리하여 상기 쉘의 탄소 전구체를 탄소로 열분해하는 단계를 포함할 수 있다.In the manufacturing method of the secondary battery electrode according to an embodiment of the present invention, the bulk manufacturing step, by pressing the raw material containing the composite particles of the core-shell structure of the electrode active material core-carbon precursor shell with a particulate electrode active material Preparing a molded body; And pyrolyzing the carbon precursor of the shell with carbon by heat treating the molded body.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 벌크제조단계는 입자상의 전극 활물질 및 탄소 전구체를 포함하는 원료를 가압 성형하여 성형체를 제조하는 단계; 및 상기 성형체를 열처리하여 상기 탄소 전구체를 탄소로 열분해하는 단계;를 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the bulk manufacturing step comprises the steps of preparing a molded body by press molding a raw material including a particulate electrode active material and a carbon precursor; And pyrolysing the carbon precursor to carbon by heat treating the molded body.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 성형체는 1방향, 2방향 또는 등방향 압축 성형에 의해 제조될 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, the molded body may be produced by one-way, two-way or isodirectional compression molding.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 절단단계 단계 후 결착단계 전, 또는 결착단계 후, 활물질 막의 적어도 일 표면을 표면 처리하는 단계가 더 수행될 수 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, after the cutting step step before the binding step, or after the binding step, the step of surface treatment of at least one surface of the active material film may be further performed.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법에 있어, 표면 처리는 표면 거칠기 조절을 포함할 수 있다.In the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, the surface treatment may include surface roughness control.
본 발명은 상술한 제조방법으로 제조된 이차전지용 전극을 포함한다.The present invention includes an electrode for secondary batteries manufactured by the above-described manufacturing method.
본 발명의 일 양태에 따른 리튬 이차전지(I)는 양극; 음극; 및 상기 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함하며, 양극 및 음극에서 하나 이상 선택되는 전극은 전극 활물질을 함유하는 활물질 막, 집전체 및 활물질 막을 집전체에 부착시키는 접착제를 포함할 수 있다.Lithium secondary battery (I) according to an aspect of the present invention is a positive electrode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the electrode selected from at least one of the positive electrode and the negative electrode may include an active material film containing an electrode active material, a current collector, and an adhesive for attaching the active material film to the current collector.
본 발명의 다른 일 양태에 따른 리튬 이차전지(II)는 양극; 음극; 및 상기 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함하며, 양극 및 음극에서 하나 이상 선택되는 전극에 포함된 활물질 막은 유기 바인더를 함유하지 않는 바인더-프리(binder-free) 막일 수 있다.Lithium secondary battery (II) according to another embodiment of the present invention is a positive electrode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the active material film included in the electrode selected from at least one of the positive electrode and the negative electrode may be a binder-free film containing no organic binder.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 프리 스탠딩 막일 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film may be a free standing film.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막의 표면에 위치하는 활물질은 잘린 입자상일 수 있다.In the lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material located on the surface of the active material film may be cut particles.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 전극 활물질을 함유하는 성형체 또는 소결체로부터 절단된 절단막일 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film may be a cut film cut from a molded or sintered body containing the electrode active material.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 활물질 막의 두께 방향을 기준하여 활물질 막 내 전극 활물질이 배향성을 가질 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film may have an orientation of the electrode active material in the active material film based on the thickness direction of the active material film.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 전극 활물질의 입자간 넥(neck)이 형성된 것일 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film may be formed between the particle neck of the electrode active material.
본 발명의 일 실시예에 따른 리튬 이차전지(I)에 있어, 활물질 막은 유기 바인더를 함유하지 않을 수 있다.In the lithium secondary battery (I) according to an embodiment of the present invention, the active material film may not contain an organic binder.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 두께 방향 단면을 기준으로, 표면영역에서의 기공률과 중앙 영역에서의 기공률의 차의 절대값을 중앙 영역에서의 기공률로 나눈 비율이 10% 이하일 수 있다..In the lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film has an absolute value of the difference between the porosity in the surface region and the porosity in the central region based on the cross section in the thickness direction. Divided by 10% or less.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 열분해 탄소 및 도전재에서 선택되는 1종 이상을 더 포함할 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film may further include one or more selected from pyrolytic carbon and a conductive material.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막의 겉보기 기공률은 10 내지 45%일 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the apparent porosity of the active material film may be 10 to 45%.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 활물질 막은 전극 활물질의 입자 및 전극 활물질의 입자간을 결착시키는 열분해 탄소를 포함할 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the active material film may include pyrolytic carbon for binding the particles of the electrode active material and the particles of the electrode active material.
본 발명의 일 실시예에 따른 리튬 이차전지(I)에 있어, 접착제는 경화능을 갖는 수지를 포함할 수 있다.In the lithium secondary battery (I) according to an embodiment of the present invention, the adhesive may include a resin having a curing ability.
본 발명의 일 실시예에 따른 리튬 이차전지(I)에 있어, 접착제는 전도성 수지, 전도성 입자 및 전도성 나노구조체에서 하나 이상 선택되는 전도성 성분을 포함할 수 있다.In the lithium secondary battery (I) according to an embodiment of the present invention, the adhesive may include a conductive component selected from at least one conductive resin, conductive particles, and conductive nanostructures.
본 발명의 일 실시예에 따른 리튬 이차전지(I, II)에 있어, 전극 활물질은 음극 활물질 또는 양극 활물질일 수 있다.In lithium secondary batteries (I, II) according to an embodiment of the present invention, the electrode active material may be a negative electrode active material or a positive electrode active material.
본 발명은 상술한 리튬 이차전지를 포함하는 리튬 이차전지 모듈을 포함한다.The present invention includes a lithium secondary battery module including the lithium secondary battery described above.
본 발명은 상술한 리튬 이차전지에 의해 전력이 공급되는 장치를 포함한다.The present invention includes a device that is powered by the above-described lithium secondary battery.
본 발명은 전해액 기반 이차전지용 활물질 막을 포함한다.The present invention includes an active material membrane for an electrolyte based secondary battery.
본 발명의 일 양태에 따른 활물질 막은 전해액이 구비되는 이차전지용 활물질 막이며, 전극 활물질을 함유하며 프리-스탠딩 가능한 이차전지용 활물질 막일 수 있다.The active material film according to an aspect of the present invention is an active material film for a secondary battery provided with an electrolyte, and may be an active material film for a secondary battery containing an electrode active material and capable of free-standing.
본 발명의 다른 일 양태에 따른 활물질 막은 전해액이 구비되는 이차전지용 활물질 막이며, 전극 활물질을 함유하고 유기 바인더를 함유하지 않는 바인더-프리 활물질막일 수 있다. The active material film according to another embodiment of the present invention is an active material film for a secondary battery provided with an electrolyte, and may be a binder-free active material film containing an electrode active material and not containing an organic binder.
본 발명의 일 실시예에 따른 활물질 막은 전극 활물질 입자간 형성된 넥(neck)이 형성된 상태일 수 있다. The active material film according to the embodiment of the present invention may be in a state in which a neck formed between the electrode active material particles is formed.
본 발명의 일 실시예에 따른 활물질 막은, 활물질 막의 두께 방향을 기준하여 활물질 막 내 전극 활물질이 배향성을 가질 수 있다.In the active material film according to the embodiment of the present invention, the electrode active material in the active material film may have an orientation based on the thickness direction of the active material film.
본 발명의 일 실시예에 따른 활물질 막은 도전재 및 열분해 탄소에서 선택되는 1종 이상을 더 포함할 수 있다.The active material film according to an embodiment of the present invention may further include at least one selected from a conductive material and pyrolytic carbon.
본 발명의 일 실시예에 따른 활물질 막은 두께 방향 단면을 기준으로, 표면영역에서의 기공률과 중앙 영역에서의 기공률의 차의 절대값을 중앙 영역에서의 기공률로 나눈 비율이 10% 이하일 수 있다.In the active material membrane according to the exemplary embodiment of the present invention, a ratio obtained by dividing the absolute value of the difference between the porosity in the surface region and the porosity in the central region by the porosity in the central region may be 10% or less based on the thickness direction cross section.
본 발명의 일 실시예에 따른 활물질 막은 열분해 탄소 및 도전재에서 선택되는 1종 이상을 더 포함할 수 있다.The active material film according to one embodiment of the present invention may further include one or more selected from pyrolytic carbon and a conductive material.
본 발명의 일 실시예에 따른 활물질 막에 있어, 활물질 막의 겉보기 기공률은 10 내지 45%일 수 있다.In the active material membrane according to an embodiment of the present invention, the apparent porosity of the active material membrane may be 10 to 45%.
본 발명은 전해액 기반 이차전지용 전극을 포함한다.The present invention includes an electrolyte-based secondary battery electrode.
본 발명에 따른 이차전지용 전극은 전해액 기반 이차전지용 전극이며, 전극활물질을 함유하고 유기 바인더를 함유하지 않는 바인더-프리 활물질 막을 포함한다.The secondary battery electrode according to the present invention is an electrolyte-based secondary battery electrode, and includes a binder-free active material film containing an electrode active material and no organic binder.
본 발명에 따른 이차전지용 전극은 전해액 기반 이차전지용 전극이며, 전극활물질을 함유하며 활물질 막이 접착제에 의해 적어도 집전체의 일 면에 결착된 전극일 수 있다.The secondary battery electrode according to the present invention is an electrolyte-based secondary battery electrode, and may be an electrode containing an electrode active material and having an active material film bound to at least one surface of a current collector by an adhesive.
본 발명의 일 실시예에 따른 이차전지용 전극에 있어, 활물질 막은 프리 스탠딩 막일 수 있다.In the secondary battery electrode according to an embodiment of the present invention, the active material film may be a free standing film.
본 발명의 일 실시예에 따른 이차전지용 전극에 있어, 활물질 막은 도전재 및 열분해 탄소에서 선택되는 1종 이상을 더 포함할 수 있다.In the secondary battery electrode according to an embodiment of the present invention, the active material film may further include one or more selected from a conductive material and pyrolytic carbon.
본 발명의 일 실시예에 따른 이차전지용 전극에 있어, 활물질 막은 전극 활물질의 입자간 형성된 넥(neck)이 형성된 상태일 수 있다.In the secondary battery electrode according to an embodiment of the present invention, the active material film may be in a state in which a neck formed between particles of the electrode active material is formed.
본 발명은 상술한 전극을 포함하는 이차전지를 포함한다.The present invention includes a secondary battery including the electrode described above.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은 활물질 벌크의 절단-부착이라는 극히 간단한 공정에 의해 이차전지용 전극이 제조됨에 따라, 공정 구축이 용이하고 저렴하며, 정밀하고 고도의 공정 제어 또한 불필요하여, 상업성이 우수한 장점이 있다.In the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, as the secondary battery electrode is manufactured by an extremely simple process of cutting-attaching an active material bulk, process construction is easy and inexpensive, and precise and high process control is also achieved. Unnecessary, there is an advantage of excellent commerciality.
기존의 이차전지 전극 제조 공정은 슬러리의 제조/검사 및 박형 전도성기재에의 연속코팅 및 건조를 수행한 후 최종 압연 및 진공건조를 하는 등의 일련의 공정을 까다롭게 관리하고 제어해야만 목적하는 수준(평활도, 부위별 무게, 밀도의 균일성등)을 만족하는 전극의 제조가 가능하였다. Existing secondary battery electrode manufacturing process must manage and control a series of processes such as final rolling and vacuum drying after slurry production / inspection, continuous coating and drying on thin conductive substrate, , The weight of each part, uniformity of density, etc.) was possible.
그러나, 본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은, 활물질 벌크의 절단-부착 공정에 기반함에 따라, 코팅공정 대신 절단(slicing) 후 부착하는 공정을 적용함으로써 기존 공정과 같이 슬러리를 박형 전도성 기재에 코팅함에 따라 발생하는 문제, 예를 들어 건조 풍량 조절에 따라 전도성 기재가 흔들리거나, 고로딩 조건의 코팅 후 건조 시 가장자리 부분과 중앙부의 건조 조건에 따른 두께 편차, 그로인해 후속 압연공정에서 가장자리 부분의 전극물질 탈리가 발생하는 문제 등으로부터 근본적으로 자유로운 장점이 있다.However, the method of manufacturing a secondary battery electrode according to an embodiment of the present invention, based on the cut-attach process of the bulk of the active material, by applying a process of slicing (slicing) instead of the coating process by applying a slurry as in the conventional process Problems caused by coating on a thin conductive substrate, for example, the conductive substrate is shaken according to the control of the drying air flow, or the thickness variation according to the drying conditions of the edge and the center during drying after coating under high loading conditions, and therefore subsequent rolling process There is an advantage that is fundamentally free from problems such as detachment of the electrode material at the edge portion.
또한, 활물질 벌크의 제조 공정에서, 비교적 소량의 용매로 혼련(kneading)함으로써 균일한 분산과 혼합이 가능하며, 코팅을 위해 점도를 묽히는 과정이 불필요하고, 점도조절을 통해 슬러리의 장기 상안정성을 확보하려는 노력이 불필요하여 공정이 간소화될 수 있다. In addition, in the manufacturing process of the bulk of the active material, it is possible to uniformly disperse and mix by kneading with a relatively small amount of solvent, and the process of diluting the viscosity for coating is unnecessary, and long-term phase stability of the slurry through viscosity control Efforts to secure them are unnecessary and the process can be simplified.
또한, 본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은, 벌크를 기반으로, 다량의 활물질 막이 제조됨에 따라, 절단-부착 공정이라는 간단한 공정에 의해, 극히 균일한 품질의 전극을 대량생산할 수 있으며, 극히 균일한 품질의 전극을 대량으로 제조할 수 있는 장점이 있다.In addition, the method for manufacturing a secondary battery electrode according to an embodiment of the present invention, as a large amount of active material film is prepared on the basis of a bulk, by a simple process called a cut-attach process, it is possible to mass-produce an electrode of extremely uniform quality And, there is an advantage that can be produced in a large amount of electrodes of extremely uniform quality.
또한, 본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은 프리-스탠딩 가능한 성형체 또는 소결체인 활물질 벌크가 절단되어 활물질 막을 제조함에 따라, 바인더-프리의 활물질 막의 제조가 가능하며, 활물질 막의 두께에 실질적인 제약이 없어 후막 형태의 활물질 막의 제조가 가능하여, 고-로딩 및 고합제 밀도를 갖는 전극의 제조가 가능한 장점이 있다. In addition, in the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention, as the active material bulk, which is a free-standing molded body or a sintered body, is cut to prepare an active material film, a binder-free active material film may be prepared, and the thickness of the active material film There is no substantial restriction on the active material film in the form of a thick film is possible, there is an advantage that the production of an electrode having a high loading and high mixture density.
상세하게, 본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은 활물질 자체로 이루어지거나, 도전재와 활물질로 이루어지거나, 활물질과 열분해 탄소로 이루어지거나, 또는 활물질, 도전재 및 열분해 탄소로 이루어진 활물질 벌크의 제조가 가능하다. 이와 함께 또는 이와 독립적으로, 두께 방향으로 제어된 열린 기공이 균일하게 형성되어 있음에 따라 활물질 막의 두께가 증가하여도 전해액이 안정적으로 침투될 수 있어, 실질적으로 막의 두께에 제한이 없다. 이와 함께 또는 이와 독립적으로 활물질 벌크 내의 입자상의 전극 활물질이 성형 과정의 압력 또는 압력과 열에 의해 고도로 충진되거나 서로 소결됨에 따라, 고-로딩 및 고합제 밀도를 갖는 전극의 제조가 가능한 장점이 있다. In detail, the method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention is made of an active material itself, made of a conductive material and an active material, made of an active material and pyrolytic carbon, or made of an active material, a conductive material, and pyrolytic carbon. The preparation of the active material bulk is possible. In addition or independently of this, since the open pores controlled in the thickness direction are uniformly formed, the electrolyte solution can stably penetrate even if the thickness of the active material film is increased, so that the thickness of the film is substantially unlimited. Together or independently of the particulate electrode active material in the bulk of the active material is highly filled or sintered with each other by the pressure or pressure and heat of the molding process, there is an advantage that it is possible to produce an electrode having a high loading and high mixture density.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은 활물질 벌크의 절단 방향으로 활물질 막의 막내 전극 활물질 입자의 배향 방향을 제어할 수 있어 전해액 함침속도, 출력특성, 율특성의 향상이 가능한 장점이 있다.The method for manufacturing a secondary battery electrode according to an embodiment of the present invention can control the orientation direction of the electrode active material particles in the film of the active material film in the cutting direction of the bulk of the active material, so that the improvement of the electrolyte impregnation rate, output characteristics, and rate characteristics is possible. have.
본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법은 활물질 막이 그 두께와 실질적으로 무관하게 균일한(설계된) 열린 기공 네트워크가 유지되어, 균일하고 안정적으로 전해액의 함침이 이루어지는 장점이 있다.The method of manufacturing an electrode for a secondary battery according to an embodiment of the present invention has an advantage that an active pore network has a uniform (designed) open pore network regardless of its thickness, so that the electrolyte solution is uniformly and stably impregnated with the electrolyte.
본 발명의 일 실시예에 따른 이차전지는 독립된 부재인 활물질 막이 유기 바인더를 함유하지 않는 바인더-프리 막일 수 있음에 따라, 고로딩 및 고합제 밀도형성이 용이해, 고에너지밀도 전지설계가 용이 구현 가능한 전극인 장점이 있다.According to an embodiment of the present invention, the secondary battery may be a binder-free film containing no organic binder, which is an independent member, so that high loading and high mixture density may be easily formed, and high energy density battery design may be easily implemented. There is an advantage of being a possible electrode.
본 발명의 일 실시예에 따른 이차전지는 독립된 부재인 활물질 막의 배향성이나 입자간 넥으로 결착된 구조등에 의해 두꺼운 후막의 형태라 할지라도 균일하고 안정적으로 전해액(및 리튬 이온)의 함침이 이루어지는 장점이 있다.The secondary battery according to an embodiment of the present invention has an advantage of uniformly and stably impregnating an electrolyte solution (and lithium ions) even in the form of a thick thick film by an orientation of an active material film or a structure bound by an interparticle neck as an independent member. have.
도 1은 본 발명의 일 실시예에　따라, 성형체인 활물질 벌크의 단면을 도시한 일 단면도이며,1 is a cross-sectional view showing a cross section of an active material bulk that is a molded article according to an embodiment of the present invention.
도 2는 본 발명이 일 실시예에 따라, 활물질 벌크를 절단하여 활물질 막을 제조하는 공정을 도시한 도면이며,2 is a view showing a process for producing an active material film by cutting the bulk of the active material according to an embodiment of the present invention,
도 3은 본 발명의 일 실시예에 따라, 소결체인 활물질 벌크에서 서로 인접하는 두 전극 활물질 입자 기준 결착 상태를 도시한 도면이며, 3 is a view showing the binding state of two electrode active material particles adjacent to each other in the bulk of the active material is a sintered body, according to an embodiment of the present invention,
도 4는 본 발명의 일 실시예에 따른 활물질 막의 단면을 도시한 일 단면도이며,4 is a cross-sectional view showing a cross section of an active material film according to an embodiment of the present invention;
도 5는 본 발명의 일 실시예에 따른 활물질 막의 단면을 도시한 다른 일 단면도이며,5 is another cross-sectional view showing a cross section of an active material film according to an embodiment of the present invention;
도 6은 본 발명의 일 실시예에 따른 전극의 단면을 도시한 일 단면도이며,6 is a cross-sectional view showing a cross section of an electrode according to an embodiment of the present invention;
도 7은 본 발명의 일 실시예에 따라 제조된 활물질 막을 관찰한 광학 사진이며,7 is an optical picture of observing an active material film prepared according to an embodiment of the present invention,
도 8은 본 발명의 일 실시예에 따라 제조된 활물질 막을 관찰한 주사전자현미경 사진이며,8 is a scanning electron microscope photograph of an active material film prepared according to an embodiment of the present invention.
도 9는 본 발명의 일 실시예에 따라 제조된 전극을 관찰한 광학 사진이다.9 is an optical picture of observing the electrode manufactured according to an embodiment of the present invention.
이하 첨부한 도면들을 참조하여 본 발명에 따른 활물질막, 이차전지용 전극, 이차전지 및 이의 제조방법을 상세히 설명한다. 다음에 소개되는 도면들은 당업자에게 본 발명의 사상이 충분히 전달될 수 있도록 하기 위해 예로서 제공되는 것이다. 따라서, 본 발명은 이하 제시되는 도면들에 한정되지 않고 다른 형태로 구체화될 수도 있으며, 이하 제시되는 도면들은 본 발명의 사상을 명확히 하기 위해 과장되어 도시될 수 있다. 이때, 사용되는 기술 용어 및 과학 용어에 있어서 다른 정의가 없다면, 이 발명이 속하는 기술 분야에서 통상의 지식을 가진 자가 통상적으로 이해하고 있는 의미를 가지며, 하기의 설명 및 첨부 도면에서 본 발명의 요지를 불필요하게 흐릴 수 있는 공지 기능 및 구성에 대한 설명은 생략한다. 명세서 전체에서 어떤 부분이 어떤 구성요소를 "포함"한다고 할 때, 이는 특별히 반대되는 기재가 없는 한 다른 구성요소를 제외하는 것이 아니라 다른 구성요소를 더 포함할 수 있는 것을 의미한다. 또한 단수형은 문구에서 특별히 언급하지 않는 한 복수형도 포함한다.Hereinafter, an active material film, a secondary battery electrode, a secondary battery, and a manufacturing method thereof according to the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided by way of example so that the spirit of the invention to those skilled in the art can fully convey. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. At this time, if there is no other definition in the technical terms and scientific terms used, it has a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs, the gist of the present invention in the following description and the accompanying drawings Descriptions of well-known functions and configurations that may be unnecessarily blurred are omitted. When any part of the specification is to "include" any component, this means that it may further include other components, except to exclude other components unless otherwise stated. In addition, singular forms also include the plural unless specifically stated otherwise in the text.
본 발명에 따른 전극의 제조방법, 활물질막, 전극 또는 이차전지를 상술함에 있어, 활물질 벌크는 전극 활물질을 함유하는 홀로 독립된 3차원 입체로, 스스로 일정한 형태를 유지하며 스스로의 무게를 지탱할 수 있는 프리 스탠딩(free-standing) 가능한 상태의 3차원 입체를 의미할 수 있다. In detailing a method for manufacturing an electrode, an active material film, an electrode, or a secondary battery according to the present invention, the active material bulk is a three-dimensionally independent three-dimensionally alone containing an electrode active material, which can maintain its own shape and support its own weight. It may refer to a three-dimensional solid state in a free-standing state.
일 예로, 벌크는 적어도 목적하는 전극의 활물질층의 설계 두께를 기준으로, 적어도 설계 두께를 초과하는 일 디멘젼(폭, 길이 또는 너비)을 갖는 크기를 의미할 수 있다. 보다 구체적으로, 벌크는 서로 직교하는 3축을 기준으로, 적어도 일 축에 따른 3차원 입체의 일 디멘젼의 크기가 제조하고자 하는 전극의 활물질 영역의 두께를 기준으로 적어도 5배, 실질적으로는 10배 이상의 크기를 가짐을 의미할 수 있다. 또한, 다른 2축 각각에 따른 3차원 입체의 각 디멘젼이 제조하고자 하는 전극의 활물질 영역의 폭이나 길이에 상응하거나 보다 더 큰 크기를 가짐을 의미할 수 있으나, 반드시 이에 제한되는 것은 아니다. For example, the bulk may refer to a size having one dimension (width, length or width) exceeding at least the design thickness based on at least the design thickness of the active material layer of the desired electrode. More specifically, the bulk is at least 5 times, substantially 10 times or more based on the thickness of the active material region of the electrode to be manufactured, the size of the three-dimensional solid dimension along at least one axis based on three axes perpendicular to each other It may mean having a size. In addition, it may mean that each dimension of the three-dimensional solid body along each of the other two axes has a size corresponding to or larger than the width or length of the active material region of the electrode to be manufactured, but is not necessarily limited thereto.
일 예로, 크기가 아닌 질량의 측면에서, 벌크는 목적하는 전극의 활물질층의 설계 중량을 기준으로, 적어도 설계 중량을 초과하는 중량을 갖는 3차원 입체를 의미할 수 있다. 보다 구체적으로, 설계 중량(목적하는 전극의 일 활물질층 중량)을 기준으로 10배 이상, 실질적으로는 50배 이상의 중량을 갖는 3차원 입체를 의미할 수 있으나, 반드시 이에 제한되는 것은 아니다.For example, in terms of mass rather than size, bulk may refer to a three-dimensional solid body having a weight that exceeds at least the design weight based on the design weight of the active material layer of the desired electrode. More specifically, it may mean a three-dimensional solid having a weight of 10 times or more, substantially 50 times or more based on the design weight (weight of one active material layer of the intended electrode), but is not necessarily limited thereto.
본 발명에 따른 전극의 제조방법, 전극 또는 이차전지를 상술함에 있어, 프리-스탠딩 가능하다 함은, 활물질 벌크나 활물질 막이 형상을 유지한 상태로 스스로의 무게를 지탱할 수 있음을 의미한다. 또한, 활물질 벌크나 활물질 막이 별도의 지지부재 없이 그 자체로 이송이나 고정(positioning)이 가능한 상태를 의미할 수 있다. 실험적으로, 프리-스탠딩 가능한 막은 폭이 1cm, 길이가 5cm 및 목적하는 이차전지의 활물질 영역 설계 두께에 부합하는 두께를 갖는 막 기준, 가운데가 비어있고 밑이 평탄하며 양측기둥이 평평한
Figure PCTKR2019003006-appb-img-000001
자 모양 지지대에 올려 막의 양측부의 2mm부분만 지지대(기둥)에 걸치도록 두어 막의 중앙부에 1g 표준분동을 올렸을 때 시편의 하방 쳐짐 정도가 1mm 이내인 상태를 의미할 수 있다. In detailing a method for manufacturing an electrode, an electrode, or a secondary battery according to the present invention, being free-standing means that the active material bulk or the active material film can support its own weight while maintaining its shape. In addition, the bulk of the active material or the active material film may mean a state in which it can be transported or fixed in itself without a separate supporting member. Experimentally, a free-standable membrane is a membrane reference having a width of 1 cm, a length of 5 cm, and a thickness corresponding to the active material area design thickness of the secondary battery of interest, with a hollow center, a flat bottom, and flat bilateral pillars.
Figure PCTKR2019003006-appb-img-000001
When placing a 2g portion of both sides of the membrane to the support (column) on the support, it may mean that the specimen is deflected below 1mm when the 1g standard weight is placed on the center of the membrane.
본 발명에 따른 이차전지용 전극의 제조방법은 활물질 벌크를 절단하여 활물질 막을 제조하는 절단단계; 및 집전체와 상기 활물질 막을 일체화하는 결착단계;를 포함한다.A method of manufacturing an electrode for a secondary battery according to the present invention includes: cutting a bulk of an active material to prepare an active material film; And a binding step of integrating a current collector and the active material film.
일 구체예에 있어, 이차전지용 전극의 제조방법은 절단 전, 입자상의 전극 활물질을 포함하는 원료를 이용하여 활물질 벌크(bulk)를 제조하는 벌크제조단계;를 더 포함할 수 있다. 즉, 본 발명의 일 실시예에 따른 이차전지용 전극의 제조방법a) 입자상의 전극 활물질을 포함하는 원료를 이용하여 활물질 벌크(bulk)를 제조하는 단계(벌크제조단계); b) 상기 활물질 벌크를 절단하여 활물질 막을 제조하는 단계(절단단계); 및 c) 집전체와 상기 활물질 막을 일체화하는 단계(결착단계);를 포함할 수 있다.In one embodiment, the method of manufacturing an electrode for a secondary battery may further include a bulk manufacturing step of manufacturing an active material bulk using a raw material including a particulate electrode active material before cutting. That is, a method of manufacturing a secondary battery electrode according to an embodiment of the present invention a) manufacturing a bulk of the active material (bulk) using a raw material containing a particulate electrode active material (bulk manufacturing step); b) cutting the bulk of the active material to prepare an active material film (cutting step); And c) integrating a current collector and the active material film (binding step).
일 구체예에 있어, 활물질 벌크는 성형체 또는 소결체일 수 있다. 이에, 활물질 벌크가 성형체인 경우 a) 단계는 원료를 압축 성형하여 성형체를 제조하는 성형 단계;를 포함할 수 있다. 또는 활물질 벌크가 소결체인 경우, 원료를 압축 성형하여 성형체를 제조하는 성형 단계; 및 성형 단계에서 제조된 성형체를 열처리하여 소결체를 제조하는 소결단계;를 포함할 수 있다.In one embodiment, the bulk of the active material may be a molded or sintered body. Thus, when the bulk of the active material is a molded article, step a) may include a molding step of manufacturing a molded article by compression molding a raw material. Or when the bulk of the active material is a sintered body, a molding step of compression molding the raw material to produce a molded body; And a sintering step of manufacturing a sintered body by heat-treating the molded body produced in the molding step.
상술한 바와 같이, 본 발명에 따른 전극의 제조방법은 집전체에 활물질을 함유하는 슬러리의 도포 및 압연(pressing)이라는 종래 슬러리 기반 공정에서 벗어나, 입자상의 전극 활물질을 포함하는 원료를 이용하여 활물질 벌크를 제조한 후, 활물질 벌크를 절단함으로써 종래 슬러리 기반 공정에서 집전체 상의 활물질층에 대응하는 활물질 막을 제조하고, 집전체와 독립되어 제조된 활물질 막을 집전체에 결착시켜 전극을 제조할 수 있다.As described above, the manufacturing method of the electrode according to the present invention deviates from the conventional slurry-based process of coating and pressing the slurry containing the active material in the current collector, bulking the active material using a raw material containing a particulate electrode active material After the preparation of the active material, the bulk of the active material may be cut to prepare an active material film corresponding to the active material layer on the current collector in a conventional slurry-based process, and an active material film prepared independently of the current collector may be bonded to the current collector to prepare an electrode.
슬러리의 도포, 건조 및 압연이라는 종래 전극 제조방법은, 유동상인 슬러리의 점도나 분산성과 같은 슬러리 자체의 특성, 구체 도포 방법이나 슬러리에 함유된 물질의 물리적(기계적) 특성및 도포된 막의 건조조건 등이 직접적으로 활물질층의 구조에 영향을 미친다. Conventional electrode production methods such as slurry application, drying and rolling include the properties of the slurry itself, such as viscosity and dispersibility of the slurry in the fluidized state, the specific application method or the physical (mechanical) properties of the material contained in the slurry, and the drying conditions of the applied film. This directly affects the structure of the active material layer.
즉, 활물질 슬러리를 이용한 전극의 제조 기술은 동적 요소에 크게 의존하여 활물질층의 구조가 결정됨에 따라, 활물질층의 정밀한 구조 제어가 현실적으로 매우 어려우며, 대면적에서의 구조적 균일성을 담보하기 어렵다. 나아가, 도포 공정으로 제조 가능한 활물질층의 두께 제약 또한 존재한다. 또한, 전극의 두께를 높여야 하는 경우는 건조공정에서 건조시간이 증가되므로 건조로의 길이가 증가되는 등의 공정변수가 변경되어야 하므로, 새로운 공정 설비의 구축이 요구되는 문제점 또한 존재한다. That is, the manufacturing technique of the electrode using the active material slurry is highly dependent on the dynamic element, and as the structure of the active material layer is determined, precise control of the active material layer is very difficult in reality, and it is difficult to ensure structural uniformity in a large area. Furthermore, there is also a thickness constraint of the active material layer which can be produced by the coating process. In addition, when the thickness of the electrode needs to be increased, the drying time is increased in the drying process, so the process parameters such as the length of the drying furnace should be changed, and thus there is a problem in that a construction of a new process facility is required.
그러나, 본 발명에 따른 전극의 제조방법은 슬러리 기반이 아닌, 기 설계된 물질, 기공 구조 및 기공률을 갖는 활물질 벌크를 절단하여 독립된 활물질 막을 제조한 후, 제조된 활물질 막을 집전체에 결착시킴으로써 전극을 제조함에 따라, 활물질 막의 구조를 정밀하고 재현성 있게 제어할 수 있다. 또한 본 발명에 따른 전극의 제조방법은 활물질 벌크를 절단하여 다량의 활물질 막의 제조가 가능하며, 액상 기반 슬러리가 아닌 완전한 고상의 활물질 벌크를 기반으로 활물질 막이 제조됨에 따라, 균일한 품질의 활물질 막을 대량 생산할 수 있는 장점이 있다.However, the method of manufacturing the electrode according to the present invention is not slurry-based, by cutting the bulk of the active material having a pre-designed material, pore structure and porosity to prepare an independent active material film, and then to produce the electrode by binding the prepared active material film to the current collector As a result, the structure of the active material film can be precisely and reproducibly controlled. In addition, the electrode manufacturing method according to the present invention is capable of producing a large amount of the active material film by cutting the bulk of the active material, as the active material film is prepared on the basis of the solid bulk of the active material rather than a liquid-based slurry, a large amount of active material film of uniform quality There is an advantage to produce.
또한, 본 발명에 따른 전극의 제조방법은 단지 활물질 벌크로부터 절단되는 막의 두께를 제어하는 단순한 방법에 의해, 집전체상 구비되는 활물질 영역의 두께가 용이 제어될 수 있다. 또한, 전해액등이 침투되는 기공이 균일하고 일정하게 유지됨에 따라 집전체상 구비되는 활물질 영역의 두께가 실질적으로 제약되지 않는 장점이 있다.In addition, the electrode manufacturing method according to the present invention can be easily controlled by the simple method of controlling the thickness of the film cut from the bulk of the active material, the thickness of the active material region provided on the current collector. In addition, there is an advantage that the thickness of the active material region provided on the current collector is not substantially constrained as the pores through which the electrolyte and the like penetrate are kept uniform and constant.
더불어, 활물질 영역의 밀도, 활물질 영역의 기공률, 활물질 영역의 두께등의 설계 변경이 이루어진다 하더라도, 단지 설계 조건을 만족하는 활물질 벌크를 제조하는 것만으로, 다양한 전극의 제조가 가능함에 따라, 설계의 자유도가 매우 높고, 전극 설계 변경에 따른 전극제조설비의 구축(또는 변경)이 요구되지 않는 장점이 있다. In addition, even if the design changes such as the density of the active material region, the porosity of the active material region, the thickness of the active material region, etc. are made, only by manufacturing the active material bulk that satisfies the design conditions, various electrodes can be manufactured, thereby providing freedom of design. Is very high, there is an advantage that the construction (or change) of the electrode manufacturing equipment according to the electrode design change is not required.
또한, 종래 슬러리 기반 기술의 경우, 활물질, 도전재, 바인더 및 용매와 같은 다양한 물질들의 수급 및 관리가 이루어져야 하며, 슬러리 믹싱, 코팅, 건조, 프레싱, 슬리팅등 고도의 다단계 공정에 기반하여 전극이 제조된다. 또한, 슬러리 제조공정의 경우 저 농도에서 고 농도로 점차적으로 농도(고형분 농도)를 증가시켜 전극 활물질 슬러리를 제조함에 따라, 분산 및 침강저감 특성을 고려하여 슬러리 농도 조절을 까다롭게 수행해야하는 등 제조공정 관리가 까다롭다. 또한, 양극의 경우 슬러리 제조시 유기 용매의 회수 장치가 별도로 구비되어야 하는 등, 제조 공정이 복잡하고 공정 설비 및 관리가 까다롭다. In addition, in the case of the conventional slurry-based technology, supply and management of various materials such as active materials, conductive materials, binders, and solvents should be made, and the electrode is based on a highly multi-step process such as slurry mixing, coating, drying, pressing, and slitting. Are manufactured. In addition, in the slurry manufacturing process, as the electrode active material slurry is prepared by gradually increasing the concentration (solid content concentration) from a low concentration to a high concentration, it is difficult to control the slurry concentration in consideration of dispersion and sedimentation reduction characteristics. It's tricky. In addition, in the case of the positive electrode, the production process of the slurry, such as the recovery device of the organic solvent must be provided separately, and the manufacturing process is complicated and the process equipment and management is difficult.
반면, 본 발명에 따른 전극의 제조방법은 슬러리에 기반하지 않고, 활물질 벌크에 기반함에 따라 유기 용매 회수 장치(단계)가 불필요 하거나 최소화 가능하고, 활물질 벌크의 제조, 절단 및 부착이라는 현저하게 간소한 공정에 의해 전극의 제조가 가능하여, 공정 설비 및 관리에 소요되는 비용을 현저하게 감소시킬 수 있다. On the other hand, the manufacturing method of the electrode according to the present invention is not based on the slurry, and based on the bulk of the active material, the organic solvent recovery apparatus (step) is unnecessary or minimized, and the remarkably simple process of preparing, cutting and attaching the bulk of the active material The manufacturing of the electrode is possible by the process, which can significantly reduce the cost for process equipment and management.
또한, 종래 슬러리 기반 기술의 경우, 활물질층의 압연 과정에서 기공 구조가 의도치 않게 붕괴되어, 실질적으로 고밀도화와 공극의 유지가 동시 구현되기 어려운 문제점이 있다. 그러나, 본 발명에 따른 제조방법은 이미 물리적(기계적)으로 안정한 강도를 가지는 활물질 벌크의 기공 구조 및 기공률이 절단된 막(활물질 막)에도 그대로 유지됨에 따라, 고밀도화와 전해액이 함침되는 공극의 유지 모두를 구현할 수 있는 장점이 있다. In addition, in the case of the conventional slurry-based technology, the pore structure is unintentionally collapsed during the rolling of the active material layer, there is a problem that it is difficult to substantially realize the high density and the maintenance of the pores at the same time. However, the manufacturing method according to the present invention, as the pore structure and the porosity of the bulk of the active material having a physically (mechanically) stable strength is still maintained in the cut film (active material film), both the densification and the maintenance of the pores impregnated with the electrolyte solution There is an advantage that can be implemented.
이에 따라, 본 발명의 일 실시예에 따른 전극의 제조방법은 단지 활물질 벌크의 기공 구조를 조절함으로써 활물질 막의 기공 구조가 제어될 수 있으며, 또한, 활물질 벌크의 기공률에 의해 활물질 막의 기공률이 제어될 수 있다. Accordingly, in the method of manufacturing the electrode according to the exemplary embodiment of the present invention, the pore structure of the active material membrane may be controlled by only adjusting the pore structure of the active material bulk, and the porosity of the active material membrane may be controlled by the porosity of the active material bulk. have.
본 발명의 일 실시예에 따른 전극의 제조방법은 전해액 기반 이차전지용 전극, 유리하게는 전해액 기반 리튬 이차전지용 전극, 보다 유리하게는 양극; 음극; 및 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함하는 리튬 이차전지용 전극의 제조방법일 수 있다. Method of manufacturing an electrode according to an embodiment of the present invention is an electrode for an electrolyte-based secondary battery, advantageously an electrode for an electrolyte-based lithium secondary battery, more advantageously an anode; cathode; And a separator interposed between the anode and the cathode; And it may be a method for producing a lithium secondary battery electrode comprising an electrolyte solution.
이는, 본 발명에서 해결하고자 하는 일 과제가, 전해액을 포함하는 리튬 이차전지에 구비되는 전극에서, 전해액이 원활히 침투 가능하면서도 고-로딩 및/또는 고합제화 가능한 전극의 제조방법을 제공하는 것이기 때문이다. This is because one problem to be solved by the present invention is to provide a method of manufacturing an electrode capable of high-loading and / or high-mixing while allowing an electrolyte solution to penetrate smoothly in an electrode provided in a lithium secondary battery including an electrolyte solution. .
본 발명의 일 실시예에 따른 전극의 제조방법은 전극 활물질의 종류에 따라, 음극의 제조방법 또는 양극의 제조방법을 포함할 수 있다. The electrode manufacturing method according to an embodiment of the present invention may include a method of manufacturing a negative electrode or a method of manufacturing a positive electrode according to the type of electrode active material.
즉, 원료에 포함되는 입자상의 전극 활물질이 음극 활물질인 경우, 일 예에 따른 전극의 제조방법은 음극의 제조방법에 상응할 수 있다. That is, when the particulate electrode active material included in the raw material is the negative electrode active material, the manufacturing method of the electrode according to an example may correspond to the manufacturing method of the negative electrode.
또한, 원료에 포함되는 입자상의 전극 활물질이 양극 활물질인 경우, 일 예에 따른 전극의 제조방법은 양극의 제조방법에 상응할 수 있다. 이에, 본 발명에 따른 전극의 제조방법이 양극 또는 음극의 제조방법만으로 국한되어 해석되어서는 안 된다.In addition, when the particulate electrode active material included in the raw material is a positive electrode active material, a method of manufacturing an electrode according to an example may correspond to a method of manufacturing a positive electrode. Therefore, the manufacturing method of the electrode according to the present invention should not be construed as being limited to the manufacturing method of the positive electrode or the negative electrode.
본 발명의 일 실시예에 따른 전극의 제조방법에 있어, 입자상의 전극 활물질을 포함하는 원료를 이용하여 활물질 벌크를 제조하는 단계는, 입자상의 전극 활물질을 포함하는 원료를 이용하여 프리-스탠딩 가능한 활물질 벌크를 제조하는 단계일 수 있다. 달리 상술하면 활물질 벌크의 제조단계는 압력(성형체의 경우) 또는 압력과 열의 인가(소결체의 경우)에 의해 입자상의 전극 활물질을 포함하는 원료로부터 물리적으로 일체인 활물질 벌크가 제조되는 단계일 수 있다.In the manufacturing method of the electrode according to an embodiment of the present invention, the step of preparing the active material bulk using a raw material containing a particulate electrode active material, the pre-standable active material using a raw material containing a particulate electrode active material It may be a step of preparing the bulk. In other words, the preparation of the active material bulk may be a step in which the active material bulk is physically integrated from a raw material including a particulate electrode active material by pressure (for a molded article) or application of pressure and heat (for a sintered body).
원료는 입자상의 전극 활물질을 포함할 수 있으며, 입자상의 입자는 구형, 플레이크형(인편상), 응집상, 무정형, 판형, 막대형, 결정형(열역학적으로 안정한 결정면으로 이루어진 결정 형상), 다면체 또는 이들의 혼합 형태일 수 있으나, 이에 한정되지 않는다. The raw material may include a particulate electrode active material, and the particulate particles may be spherical, flake (flake), aggregated, amorphous, plate, rod, crystalline (crystalline form consisting of thermodynamically stable crystal faces), polyhedron or these It may be a mixed form of, but is not limited thereto.
원료에 함유되는 전극 활물질은 1종의 전극 활물질; 또는 조성, 결정구조, 입자 형상, 기계적 특성 또는 물리적 특성이 상이한 2종 이상의 전극 활물질;을 포함할 수 있다. 이때, 결정 구조가 상이하다 함은 동일 조성에 상이한 결정 구조를 갖는 동질 이상의 경우 또한 포함한다. 또한, 입자 형상이 상이하다 함은 서로 상이한 물질의 서로 상이한 입자 형상뿐만 아니라, 일 물질의 서로 상이한 입자 형상의 의미를 포함한다. 일 예로, 일 물질의 결정 입자(primary particle, 또는 crystalline particle)와 동일 일 물질의 응집 입자(secondary particle), 일 물질의 구형 입자와 동일 일 물질의 플레이크형 입자등을 들 수 있으나, 명확한 이해를 돕기 위해 제시된 것일 뿐, 이에 한정되는 것은 아니다. 또한, 기계적 특성은 경도(hardness), 강도(strength), 인성(toughness) 및 연성(ductility)등에서 하나 이상 선택된 특성을 포함할 수 있으며, 물리적 특성은 전기전도도, 열전도도, 열팽창률 및 비중등에서 하나 이상 선택된 특성을 포함할 수 있다. The electrode active material contained in a raw material is 1 type of electrode active material; Or two or more electrode active materials having different compositions, crystal structures, particle shapes, mechanical properties, or physical properties. In this case, the different crystal structures also include cases of homogeneous or more having different crystal structures in the same composition. In addition, different particle shapes include meanings of different particle shapes of different materials as well as different particle shapes of one material. For example, there may be mentioned primary particles or crystalline particles of one material, secondary particles of the same material, and flake particles of the same material as spherical particles of one material. It is presented to assist, but is not limited to. In addition, the mechanical properties may include one or more selected properties such as hardness, strength, toughness, and ductility, and physical properties include one of electrical conductivity, thermal conductivity, thermal expansion rate, and specific gravity. It may include the characteristic selected above.
일 예로, 원료에 함유되는 전극 활물질은 음극 활물질일 수 있으며, 음극 활물질은 이차전지의 음극에 통상적으로 사용되는 물질이면 사용 가능하다. 구체적인 일 예로, 음극 활물질은 이흑연화성 탄소; 난흑연화성 탄소; 천연 흑연; 인조 흑연; 탄소나노튜브; 그래핀; 실리콘; Sn 합금; Si 합금; Sn, Si, Ti, Ni, Fe 및 Li에서 하나 또는 둘 이상 선택되는 원소의 산화물(일 예로, Sn 산화물, Si 산화물, Ti 산화물, Ni 산화물, Fe 산화물(FeO) 및 리튬-티타늄 산화물(LiTiO 2, Li 4Ti 5O 12); 또는 이들의 혼합물을 포함할 수 있으나, 이에 한정되는 것은 아니다.For example, the electrode active material contained in the raw material may be a negative electrode active material, and the negative electrode active material may be used as long as it is a material commonly used for the negative electrode of the secondary battery. As a specific example, the negative electrode active material is digraphitizable carbon; Non-graphitizable carbon; Natural graphite; Artificial graphite; Carbon nanotubes; Graphene; silicon; Sn alloys; Si alloys; Oxides of one or more elements selected from Sn, Si, Ti, Ni, Fe and Li (eg, Sn oxide, Si oxide, Ti oxide, Ni oxide, Fe oxide (FeO) and lithium-titanium oxide (LiTiO 2 , Li 4 Ti 5 O 12 ); or a mixture thereof, but is not limited thereto.
다른 일 예로, 원료에 함유되는 전극 활물질은 양극 활물질일 수 있으며, 양극 활물질은 충방전에 관여하는 이온(일 예로 리튬 이온)의 가역적인 탈/삽입이 가능한 물질이면 사용 가능하며, 통상적인 이차전지의 양극에 사용되는 전극 물질이면 무방하다. As another example, the electrode active material contained in the raw material may be a positive electrode active material, and the positive electrode active material may be used as long as it is a material capable of reversible insertion / removal of ions (for example, lithium ions) involved in charging and discharging. The electrode material used for the anode may be sufficient.
대표적인 예로, 양극 활물질은 코발트, 망간, 니켈에서 선택되는 최소한 1종 과 리튬의 복합산화물 중 1종 이상일 수 있다. 이러한 복합산화물의 일 예로 다음의 화합물들을 들 수 있다. Li xMn 1 - yM yA 2, LixMn 1 - yM yO 2 - zX z, Li xMn 2O 4 - zX z, Li xMn 2 -yMyM' zA 4, Li xCo 1 - yM yA 2, Li xCo 1 - yM yO 2 - zX z, Li xNi 1 - yM yA 2, Li xNi 1 - yM yO 2 - zX z, Li xNi 1 - yCo yO 2 - zX z, Li xNi 1-y-zCo yM zA α, Li xNi 1 -y- zCo yM zO 2 - αX α, Li xNi 1 -y- zMn yM zA α, Li xNi 1 -y- zMn yM zO 2 - αX, 식 중에서, 0.9≤x≤1.1, 0≤y≤0.5, 0≤z≤0.5, 0≤α≤2이고, M과 M'은 동일하거나 서로 다르며, Mg, Al,Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Mn, Cr, Fe, Sr, V 및 희토류 원소로 이루어진 군에서 선택되며, A는 O, F, S 및 P로 이루어진 군에서 선택되고, X는 F, S 및 P로 이루어진 군에서 선택된다.As a representative example, the cathode active material may be at least one selected from cobalt, manganese, nickel, and at least one of a composite oxide of lithium. Examples of such composite oxides include the following compounds. Li x Mn 1 - y M y A 2 , LixMn 1 - y M y O 2 - z X z , Li x Mn 2 O 4 - z X z , Li x Mn 2 -y MyM ' z A 4 , Li x Co 1 - y M y A 2 , Li x Co 1 - y M y O 2 - z X z , Li x Ni 1 - y M y A 2 , Li x Ni 1 - y M y O 2 - z X z , Li x Ni 1 - y Co y O 2 - z X z , Li x Ni 1-yz Co y M z A α , Li x Ni 1 -y- z Co y M z O 2 - α X α , Li x Ni 1 -y- z Mn y M z A α , Li x Ni 1 -y- z Mn y M z O 2 - from α X, expression, 0.9≤x≤1.1, 0≤y≤0.5, 0≤z≤0.5, 0≤α≤2, M and M 'are the same or different, Mg, Al, Co, K, Na, Ca, Si, Ti, Sn, V, Ge, Ga, B, As, Zr, Mn, Cr , Fe, Sr, V and rare earth elements, A is selected from the group consisting of O, F, S and P, X is selected from the group consisting of F, S and P.
대표적인 예로, 양극 활물질은 층상 구조의 리튬-금속 산화물; 스피넬 구조의 리튬-금속 산화물; 올리빈 구조의 리튬-금속 포스페이트; 또는 이들의 혼합물을 포함할 수 있다. 보다 구체적으로, 층상 구조의 리튬-금속 산화물은 LiMO 2(M은 Co 및 Ni에서 하나 또는 둘 이상 선택되는 전이금속); Mg, Al, Fe, Ni, Cr, Zr, Ce, Ti, B 및 Mn에서 하나 또는 둘 이상 선택되는 이종 원소로 치환되거나, 이러한 이종 원소의 산화물로 코팅된 LiMO 2(M은 Co 및 Ni 에서 하나 또는 둘 이상 선택되는 전이금속); Li xNi αCo βM γO 2(0.9≤x≤1.1인 실수, 0.7≤α≤0.9인 실수, 0.05≤β≤0.35인 실수, 0.01≤γ≤0.1인 실수, α + β + γ =1, M은 Mg, Sr, Ti, Zr, V, Nb, Ta, Mo, W, B, Al, Fe, Cr, Mn 및 Ce로 이루어진 군에서 하나 이상 선택되는 원소); 또는 Li xNi aMn bCo cM dO 2(0.9≤x≤1.1인 실수, 0.3≤a≤0.6인 실수, 0.3≤b≤0.4인 실수, 0.1≤c≤0.4인 실수, a+b+c+d=1, M은 Mg, Sr, Ti, Zr, V, Nb, Ta, Mo, W, B, Al, Fe, Cr 및 Ce로 이루어진 군에서 하나 이상 선택되는 원소)등을 포함할 수 있으나, 이에 한정되는 것은 아니다. 스피넬 구조의 리튬-금속 산화물은 Li aMn 2 -xM xO 4(M=Al, Co, Ni, Cr, Fe, Zn, Mg, B 및 Ti에서 하나 또는 둘 이상 선택되는 원소, 1≤a≤1.1인 실수, 0≤x≤0.2인 실수) 또는 Li 4Mn 5O 12등을 포함할 수 있으나, 이에 한정되는 것은 아니다. 올리빈 구조의 포스페이트계 물질은 LiMPO 4(M은 Fe, Co, Mn)등을 포함할 수 있으나, 이에 한정되는 것은 아니다.As a representative example, the positive electrode active material may be a lithium-metal oxide having a layered structure; Spinel structure lithium-metal oxides; Lithium-metal phosphate of olivine structure; Or mixtures thereof. More specifically, the layered lithium-metal oxide is LiMO 2 (M is a transition metal selected from one or two or more from Co and Ni); LiMO 2 substituted with one or more heteroatoms selected from Mg, Al, Fe, Ni, Cr, Zr, Ce, Ti, B and Mn, or coated with oxides of these heteroatoms (M is one from Co and Ni Or transition metals selected from two or more); Li x Ni α Co β M γ O 2 (real number 0.9≤x≤1.1, real number 0.7≤α≤0.9, real number 0.05≤β≤0.35, real number 0.01≤γ≤0.1, α + β + γ = 1 , M is one or more elements selected from the group consisting of Mg, Sr, Ti, Zr, V, Nb, Ta, Mo, W, B, Al, Fe, Cr, Mn and Ce); Or Li x Ni a Mn b Co c M d O 2 (real number 0.9≤x≤1.1, real number 0.3≤a≤0.6, real number 0.3≤b≤0.4, real number 0.1≤c≤0.4, a + b + c + d = 1, M may include Mg, Sr, Ti, Zr, V, Nb, Ta, Mo, W, B, Al, Fe, Cr and Ce) However, the present invention is not limited thereto. The spinel-structured lithium-metal oxide is Li a Mn 2 -x M x O 4 (M = Al, Co, Ni, Cr, Fe, Zn, Mg, B and Ti, an element selected from one or more, 1≤a Real number ≤ 1.1, real number 0 ≤ x ≤ 0.2) or Li 4 Mn 5 O 12 And the like , but is not limited thereto. The phosphate-based material of the olivine structure may include LiMPO 4 (M is Fe, Co, Mn) and the like, but is not limited thereto.
또한, 입자상의 입자는 1차 입자(primary particle, crystalline particle), 응집 입자(secondary particle), 무정형 입자, 구형 입자, 플레이크 입자, 침상 입자등의 입자뿐만 아니라 코어-쉘 구조의 복합 입자를 포함할 수 있다. In addition, particulate particles may include core-shell structured composite particles as well as particles such as primary particles (crystalline particles), aggregated particles (secondary particles), amorphous particles, spherical particles, flake particles, acicular particles, and the like. Can be.
구체적으로, 입자상의 입자는 전극 활물질의 코어; 이종 물질의 쉘;의 코어-쉘 구조의 복합 입자일 수 있으며, 쉘의 이종 물질은 제2전극활물질, 전극활물질의 전구체, 전도성물질, 전도성물질의 전구체, 바인더(제1바인더) 또는 이들의 혼합물을 포함할 수 있다.Specifically, the particulate particles are the core of the electrode active material; It may be a composite particle of the core-shell structure of the shell of the heterogeneous material, the heterogeneous material of the shell is the second electrode active material, the precursor of the electrode active material, the conductive material, the precursor of the conductive material, the binder (first binder) or a mixture thereof It may include.
쉘이 전극활물질의 전구체나 전도성물질의 전구체를 포함할 수 있는 구성은, 본 발명의 일 예에 따라, 벌크화를 위한 열 인가과정에서 물질의 합성이나 전환 또한 이루어질 수 있기 때문이다. 즉, 열 인가에 의한 원료의 벌크화시 전도성 물질이나 전극활물질의 제조가 인-시츄(in-situ)로 이루어질 수 있음에 따라, 전극 활물질의 코어;와 전극활물질의 전구체나 전도성물질의 전구체와 같은 전구물질의 쉘의 복합 입자를 입자상으로 사용할 수 있다. The configuration in which the shell may include a precursor of an electrode active material or a precursor of a conductive material is because, according to an example of the present invention, the synthesis or conversion of the material may also be performed during the heat application process for bulking. That is, since the production of the conductive material or the electrode active material may be made in-situ during the bulking of the raw material by heat application, the core of the electrode active material; and the precursor of the electrode active material or the precursor of the conductive material; Composite particles of a shell of the same precursor can be used in particulate form.
상술한 바와 같이, 원료의 벌크화와 전구물질의 물질 전환이 동시에 이루어질 수 있으나, 필요시 성형이나 소결로 벌크화가 이루어지기 전 또는 후 전구 물질의 물질 전환을 위한 별도의 열 인가가 이루어질 수도 있음은 물론이다. 이때, 전극활물질의 전구체는 코어와 동종인 전극활물질의 전구체이거나, 코어와 상이한(이종의) 전극활물질의 전구체일 수 있다. As described above, the bulking of the raw material and the material conversion of the precursor may be simultaneously performed, but if necessary, a separate heat application may be performed before or after the bulking of the molding or sintering furnace. Of course. In this case, the precursor of the electrode active material may be a precursor of an electrode active material that is the same as the core, or may be a precursor of an electrode active material different from the core (heterogeneous).
전극(음극 또는 양극) 활물질의 전도성이 떨어지는 경우, 복합 입자의 쉘은 전도성 물질이나 전도성 물질의 전구체일 수 있다. 전도성 물질은 전극 활물질층의 전기전도도를 향상시키기 위해, 활물질 슬러리에 통상적으로 혼입되는 도전재로 알려진 물질이면 사용 가능하다. 전도성 물질의 구체적인 일 예로, 카본 블랙, 아세틸렌 블랙, 케첸 블랙, 채널 블랙, 파네스 블랙, 램프 블랙, 서멀 블랙, 탄소나노튜브, 탄소섬유(기상성장탄소섬유(VGCF) 포함) 및 박리흑연 또는 이들의 혼합물등의 전도성 탄소체를 들 수 있으나, 이에 한정되는 것은 아니다. When the conductivity of the electrode (cathode or cathode) active material is poor, the shell of the composite particle may be a conductive material or a precursor of the conductive material. The conductive material can be used as long as it is a material known as a conductive material that is commonly incorporated into the active material slurry in order to improve the electrical conductivity of the electrode active material layer. Specific examples of the conductive material include carbon black, acetylene black, ketjen black, channel black, farnes black, lamp black, thermal black, carbon nanotubes, carbon fibers (including VGCF) and exfoliated graphite or these Conductive carbon bodies such as mixtures thereof, but is not limited thereto.
전도성 물질의 전구체는 탄소 전구체로 알려진 물질이면 무방하다. 일 예로, 전도성 물질의 전구체는 열분해에 의해 탄소로 전환되는 탄소 전구체를 들 수 있다. 구체적인 일 예로, 탄소 전구체는 코크스, 피치, 열경화성 수지 및 열가소성 수지등에서 선택되는 1종 이상을 들 수 있다. 코크스는 석유 또는 석탄계 코크스 (petroleum or coal tar pitch derived cokes)를 포함할 수 있으며, 피치는 석유계피치, 석탄계피치 또는 이들의 혼합물을 포함할 수 있다. 피치는 등방성 피치, 메소페이스 피치 또는 이들의 혼합물등을 포함할 수 있다. 탄소 전구체로 사용되는 수지는 열경화성 수지, 열가소성 수지 또는 이들의 혼합물일 수 있다. 열경화성 수지는 에폭시 수지, 폴리에스터 수지, 페놀 수지, 알키드(불포화폴리에스테르) 수지, 폴리이미드 수지, 비닐에스터 수지, 폴리우레탄 수지, 폴리이소시아누레이트 수지, 또는 이들의 혼합물등을 들 수 있으며, 열가소성 수지는 폴리에틸렌 수지, 폴리프로필렌 수지, 폴리비닐알코올 수지, 폴리염화비닐리덴 수지, 폴리에틸렌테레프탈레이트 수지, 폴리에스테르 수지, 폴리스티렌 수지, 폴리메틸메타크릴레이트 수지, 폴리염화비닐 수지, ABS(Acrylonitrile Butadien Stylene) 수지, 폴리아미드 수지, 폴리카보네이트 수지, 폴리옥시메틸렌 수지, 아크릴 수지, 폴리비닐설파이드 수지, 폴리에테르에테르케톤 수지, 폴리테트라플루오르에틸렌 수지 또는 이들의 혼합물등을 들 수 있으나, 이에 한정되는 것은 아니다. The precursor of the conductive material may be a material known as a carbon precursor. For example, the precursor of the conductive material may include a carbon precursor that is converted to carbon by pyrolysis. As a specific example, the carbon precursor may be at least one selected from coke, pitch, thermosetting resin and thermoplastic resin. The coke may include petroleum or coal tar pitch derived cokes, and the pitch may include petroleum pitch, coal pitch or mixtures thereof. The pitch may include an isotropic pitch, mesophase pitch, or a mixture thereof. The resin used as the carbon precursor may be a thermosetting resin, a thermoplastic resin or a mixture thereof. The thermosetting resin may be an epoxy resin, a polyester resin, a phenol resin, an alkyd (unsaturated polyester) resin, a polyimide resin, a vinyl ester resin, a polyurethane resin, a polyisocyanurate resin, or a mixture thereof, and the like. The resin is polyethylene resin, polypropylene resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polyethylene terephthalate resin, polyester resin, polystyrene resin, polymethyl methacrylate resin, polyvinyl chloride resin, ABS (Acrylonitrile Butadien Stylene) Resins, polyamide resins, polycarbonate resins, polyoxymethylene resins, acrylic resins, polyvinylsulfide resins, polyetheretherketone resins, polytetrafluoroethylene resins, or mixtures thereof, but are not limited thereto.
쉘이 탄소 전구체를 포함하는 경우, 알려진 바와 같이, 탄소 전구체로부터 전환된 탄소(열분해 탄소)에도 충방전에 관여하는 이온(일 예로 리튬 이온)의 삽입이 발생할 수 있으며, 나아가, 탄소 전구체가 탄소로 전환되며 입자상의 전극 활물질들을 결착하는 역할 또한 수행할 수 있다. 이에, 탄소 전구체가 단지 전도성 물질의 전구체로 한정되어 해석되어서는 안되며, 바인더 및/또는 전극활물질의 전구체로도 해석될 수 있음을 간과하여서는 안된다.When the shell comprises a carbon precursor, as is known, the insertion of ions (eg lithium ions) involved in charging and discharging may also occur in the carbon (pyrolysis carbon) converted from the carbon precursor, and furthermore, the carbon precursor is converted into carbon It may also serve to bind and bind the electrode active material in the form of particles. Thus, the carbon precursor should not be construed as being limited only to the precursor of the conductive material, and may not be interpreted as a precursor of the binder and / or the electrode active material.
쉘이 바인더(제1바인더)를 함유하는 경우, 바인더는 유기 바인더를 포함할 수 있으며, 유기 바인더는 활물질간 및 활물질과 집전체간의 결착을 위해 리튬 이차전지의 전극에 통상적으로 사용되는 고분자이면 족하다. 구체적 일 예로, 바인더는 폴리비닐리덴 플루오라이드, 폴리비닐리덴 플루오라이드-헥사플루오로프로필렌 공중합체, 폴리비닐리덴플루오라이드-트리클로로에틸렌 공중합체, 폴리메틸메타크릴레이트, 폴리아크릴로니트릴, 폴리비닐피롤리돈, 폴리비닐아세테이트, 폴리에틸렌-비닐 아세테이트 공중합체, 폴리에틸렌옥사이드, 셀룰로오스 아세테이트, 셀룰로오스 아세테이트 부티레이트, 셀룰로오스 아세테이트 프로피오네이트, 시아노에틸풀루란, 시아노에틸폴리비닐알콜, 시아노에틸셀룰로오스, 시아노에틸수크로오스, 풀루란, 카르복실 메틸 셀룰로오스, 스티렌-부타디엔 공중합체, 아크릴로니트릴-스티렌-부타디엔 공중합체, 폴리이미드, 폴리테트라플루오로에틸렌 또는 이들의 혼합물등을 들 수 있으나, 본 발명이 바인더 물질에 의해 한정될 수 없음은 물론이다. When the shell contains a binder (first binder), the binder may include an organic binder, and the organic binder may be a polymer commonly used for electrodes of lithium secondary batteries for binding between active materials and between an active material and a current collector. . As a specific example, the binder may be polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride-trichloroethylene copolymer, polymethyl methacrylate, polyacrylonitrile, polyvinyl Pyrrolidone, polyvinylacetate, polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, cya Noethyl sucrose, pullulan, carboxyl methyl cellulose, styrene-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polyimide, polytetrafluoroethylene or mixtures thereof, but the present invention is a binder Can be limited by substance None of course.
원료가 전극활물질 코어- 바인더 쉘의 복합 입자상의 전극 활물질을 함유하는 경우, 구체 벌크화 방법에 따라, 활물질 벌크는 복합 입자의 쉘로부터 유래한 바인더(유기 바인더)를 함유하거나, 복합 입자의 쉘에 함유된 바인더(유기 바인더)가 탄화 내지 열분해되어 잔류하는 탄소를 함유할 수 있다. When the raw material contains an electrode active material in the form of a composite particle of an electrode active material core-binder shell, according to the specific bulking method, the active material bulk contains a binder (organic binder) derived from the shell of the composite particles, or the shell of the composite particles. The contained binder (organic binder) may contain carbon remaining after carbonization or pyrolysis.
복합 입자를 이용하여 활물질 벌크를 제조하는 구체적인 일 예로, 활물질 벌크 제조 단계는, 입자상의 전극 활물질로 전극 활물질 코어-탄소 전구체 쉘의 코어-쉘 구조의 복합 입자를 포함하는 원료를 가압 성형하여 성형체를 제조하는 단계; 및 성형체를 열처리하여 상기 쉘의 탄소 전구체를 탄소로 열분해하는 단계;를 포함할 수 있다. 이때, 전극 활물질 코어는 양극활물질 또는 음극활물질일 수 있다. As a specific example of manufacturing the active material bulk using the composite particles, the active material bulk manufacturing step, by pressing the raw material containing the composite particles of the core-shell structure of the electrode active material core-carbon precursor shell with a particulate electrode active material to form a molded body Manufacturing step; And pyrolyzing the carbon precursor of the shell with carbon by heat-treating the molded body. In this case, the electrode active material core may be a positive electrode active material or a negative electrode active material.
원료는 상술한 입자상의 전극 활물질과 함께, 바인더(제2바인더), 도전재, 탄소 전구체 및 기공 형성제에서 하나 이상 선택되는 첨가제를 더 포함할 수 있다. The raw material may further include an additive selected from at least one of a binder (second binder), a conductive material, a carbon precursor, and a pore-forming agent together with the above-mentioned particulate electrode active material.
또한, 원료가 바인더를 포함하는 경우나, 보다 고르고 신속한 물질의 혼합이 요구되는 경우, 원료는 첨가제로 함유되는 바인더(제2바인더)를 용해하는 용매 또는 원료를 분산시키는 분산매 더 포함할 수 있다. In addition, when the raw material includes a binder, or when a more even and rapid mixing of materials is required, the raw material may further include a solvent for dissolving the binder (second binder) contained as an additive or a dispersion medium for dispersing the raw material.
첨가제로 원료에 함유되는 바인더(제2바인더)는 통상의 이차전지에 사용되는 수계 유기 바인더 및/ 또는 비수계 유기 바인더일 수 있다. 구체적으로, 비수계 바인더는 비닐리덴플루오라이드-헥사플루오로프로필렌 코폴리머(PVDF-co-HEP), 폴리비닐리덴플루오라이드(polyvinylidenefluoride), 폴리아크릴로니트릴(polyacrylonitrile), 폴리메틸메타크릴레이트(polymethylmethacrylate), 폴리비닐알코올, 카르복시메틸셀룰로오스(CMC), 전분, 히드록시프로필셀룰로오스, 재생 셀룰로오스, 폴리비닐피롤리돈, 테트라플루오로에틸렌, 폴리에틸렌, 폴리프로필렌, 폴리아크릴산, 에틸렌-프로필렌-디엔 모노머(EPDM), 술폰화 에틸렌프로필렌 터폴리머(EPDM), 폴리테트라플루오로에틸렌(PTFE), 폴리비닐리덴 플루오라이드(PVdF) 등을 들 수 있으며, 수계 바인더는 아크릴로나이트릴-부타디엔고무, 스티렌-부타디엔 고무 또는 아크릴 고무 등을 들 수 있으나, 이에 한정되는 것은 아니다. The binder (second binder) contained in the raw material as an additive may be an aqueous organic binder and / or a non-aqueous organic binder used in a conventional secondary battery. Specifically, the non-aqueous binder is vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HEP), polyvinylidene fluoride (polyvinylidenefluoride), polyacrylonitrile, polymethyl methacrylate (polymethylmethacrylate) ), Polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, ethylene-propylene-diene monomer (EPDM ), Sulfonated ethylene propylene terpolymer (EPDM), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF) and the like, and the aqueous binder is acrylonitrile-butadiene rubber, styrene-butadiene rubber Or acrylic rubber, etc., but is not limited thereto.
성형 또는 소결이라는 벌크화의 구체 방법에 따라, 활물질 벌크는 첨가제로 첨가되는 바인더를 함유하거나, 첨가제로 첨가된 바인더가 탄화 내지 열분해되어 잔류하는 탄소를 함유할 수 있다. According to a specific method of bulking such as molding or sintering, the active material bulk may contain a binder added as an additive, or the binder added as an additive may contain carbon remaining after carbonization or pyrolysis.
도전재는 이차전지 분야에서 활물질층의 전도도를 향상시키기 위해 일반적으로 사용될 수 있는 것이라면 특별하게 제한되지 않는다. 일 예로, 전도성 탄소, 전도성 고분자 및 금속에서 하나 또는 둘 이상 선택된 물질의 입자, 섬유, 나노구조체 또는 이들의 혼합물등을 포함할 수 있다. The conductive material is not particularly limited as long as it can be generally used to improve the conductivity of the active material layer in the secondary battery field. For example, the particles may include particles, fibers, nanostructures, or mixtures thereof of one or more materials selected from conductive carbon, conductive polymers, and metals.
예를 들면, 전도성 탄소, 전도성 고분자 및 금속에서 하나 또는 둘 이상 선택된 물질(도전재 물질)은 인조 흑연, 천연 흑연, 소프트카본, 하드카본,카본 블랙, 아세틸렌 블랙, 케첸 블랙, 덴카 블랙, 써멀 블랙, 채널 블랙, 알루미늄, 주석, 비스무트, 실리콘, 안티몬, 니켈, 구리, 티타늄, 바나듐, 크롬, 망간, 철, 코발트, 아연, 몰리브덴, 텅스텐, 은, 금, 란타늄, 루테늄, 백금, 이리듐, 산화티탄, 산화아연, 티탄산 칼륨, 불화카본, 폴리아닐린, 폴리티오펜, 폴리아세틸렌, 폴리피롤 또는 이들의 조합 등을 포함할 수 있다.For example, one or more materials selected from conductive carbon, conductive polymers, and metals (conductive materials) include artificial graphite, natural graphite, soft carbon, hard carbon, carbon black, acetylene black, ketjen black, denka black, thermal black. , Channel black, aluminum, tin, bismuth, silicon, antimony, nickel, copper, titanium, vanadium, chromium, manganese, iron, cobalt, zinc, molybdenum, tungsten, silver, gold, lanthanum, ruthenium, platinum, iridium, titanium oxide , Zinc oxide, potassium titanate, carbon fluoride, polyaniline, polythiophene, polyacetylene, polypyrrole or combinations thereof.
도전재는 상술한 도전재 물질의 입자(무정형 입자를 포함함)형, 판형, 막대형, 와이어형(섬유형) 또는 이들의 혼합 형상일 수 있으며, 이와 함께 또는 이를 대체하여 상술한 도전재 물질의 나노구조체를 포함할 수 있다. 나노구조체는 나노와이어, 나노튜브, 나노판, 나노리본, 나노입자 및 나노막대에서 하나 또는 둘 이상 선택될 수 있다. 이러한 나노구조체는 나노구조체의 네트워크에 의해 활물질 벌크(및 활물질 막)의 모든 방향으로 균일하며 우수한 전기전도도를 담보할 수 있다. The conductive material may be particles (including amorphous particles), plate, rod, wire (fiber), or a mixture thereof, of the aforementioned conductive material, and together with or in place of the conductive material described above. It may include nanostructures. The nanostructures may be selected from one or two or more from nanowires, nanotubes, nanoplatelets, nanoribbons, nanoparticles and nanorods. Such nanostructures can ensure uniform and excellent electrical conductivity in all directions of the bulk of the active material (and active material film) by a network of nanostructures.
이때, 도전재는 활물질 벌크 및 활물질 막의 전기전도도를 향상시키는 역할과 함께, 소결체 제조를 위한 열처리 공정 또는 별도의 에너지 인가 공정에 의해 도전재의 용융 결착(부분적 용융을 포함함)이 발생하는 경우, 활물질 입자간을 결착시키는 결착제의 역할 또한 수행할 수 있다. In this case, the conductive material serves to improve the electrical conductivity of the bulk of the active material and the active material film, and active material particles when melt bonding (including partial melting) of the conductive material occurs by a heat treatment process or a separate energy application process for producing a sintered body. It may also play the role of a binder that binds the liver.
기공형성제는 원료의 벌크화 과정에서 또는 벌크화 후, 분해 또는 용해 제거될 수 있다. 기공형성제는 탄화수율이 40% 이하, 구체적으로 탄화수율이1 내지 20%인 고분자이면 사용 가능하다. 이때, 고분자의 탄화수율은 99.99% 이상 순도의 N 2 환원가스 분위기의 900℃ 탄화 조건 기준 탄화수율일 수 있다. Pore formers may be decomposed or dissolved away during bulking of the raw materials or after bulking. The pore-forming agent can be used as long as the carbon yield is 40% or less, specifically, a polymer having a carbon yield of 1 to 20%. In this case, the carbonization yield of the polymer may be a carbonization yield based on 900 ℃ carbonization conditions in the N 2 reducing gas atmosphere of 99.99% or more purity.
보다 구체적으로, 기공형성제는 탄화수율이 40% 이하, 구체적으로 탄화수율이1 내지 20%이며, 잔류 탄소에서 고정탄소의 함량이 99중량 % 이상인 고분자일 수 있다. 활물질 벌크에 잔류 기공을 형성하는 기공형성제의 구체적인 예로, 폴리스틸렌, 폴리비닐알코올, 폴리비닐클로라이드, 에폭시레진, 페놀레진, 폴리프로필렌, 또는 이들의 혼합물등을 들 수 있으나, 이에 한정되는 것은 아니다. 기공형성제는 구형 내지 섬유상일 수 있으나, 이에 한정되는 것은 아니다. More specifically, the pore-forming agent may be a polymer having a carbon yield of 40% or less, specifically, a carbon yield of 1-20%, and a content of fixed carbon in residual carbon of 99% by weight or more. Specific examples of the pore-forming agent for forming residual pores in the bulk of the active material include, but are not limited to, polystyrene, polyvinyl alcohol, polyvinyl chloride, epoxy resin, phenol resin, polypropylene, or a mixture thereof. The pore former may be spherical to fibrous, but is not limited thereto.
첨가제로 원료에 함유되는 탄소 전구체는 코크스, 피치, , 열 경화성 수지 및 열 가소성 수지에서 선택되는 1종 이상을 포함할 수 있다. 코크스는 석유 또는 석탄계 코크스 (petroleum or coal tar pitch derived cokes)를 포함할 수 있으며, 피치는 석유계피치, 석탄계피치 또는 이들의 혼합물을 포함할 수 있다. 피치는 등방성 피치, 메소페이스 피치 또는 이들의 혼합물등을 포함할 수 있다. 탄소 전구체로 사용되는 수지는 열경화성 수지, 열가소성 수지 또는 이들의 혼합물일 수 있다. 열경화성 수지는 에폭시 수지, 폴리에스터 수지, 페놀 수지, 알키드(불포화 폴리 에스테르) 수지, 폴리이미드 수지, 비닐에스터 수지, 폴리우레탄 수지, 폴리이소시아누레이트 수지, 또는 이들의 혼합물등을 들 수 있으며, 열가소성 수지는 폴리에틸렌 수지, 폴리프로필렌 수지, 폴리비닐알코올 수지, 폴리염화비닐리덴 수지, 폴리에틸렌테레프탈레이트 수지, 폴리에스테르 수지, 폴리스티렌 수지, 폴리메틸메타크릴레이트 수지, 폴리염화비닐 수지, ABS(Acrylonitrile Butadien Stylene) 수지, 폴리아미드 수지, 폴리카보네이트 수지, 폴리옥시메틸렌 수지, 아크릴 수지, 폴리비닐설파이드 수지, 폴리에테르에테르케톤 수지, 폴리테트라플루오르에틸렌 수지 또는 이들의 혼합물등을 들 수 있으나, 이에 한정되는 것은 아니다. 특별히 한정되지 않으나, 탄소 전구체로 사용되는 수지의 탄화수율은 10% 이상일 수 있으며, 구체적으로30 내지 90%, 보다 구체적으로 40 내지 90%일 수 있다. 이때, 탄화수율이 40% 이하인 수지계 탄소 전구체를 사용하는 경우, 탄소 전구체가 기공형성제의 역할 또한 수행할 수도 있다. 상술한 바와 같이 탄소 전구체가 열분해되어 생성되는 탄소(열분해 탄소)는 도전재의 역할과 활물질간을 결착시키는 결착제의 역할을 수행할 수 있으며, 충방전 반응에 관여하는 활물질의 역할 또한 수행할 수 있다. The carbon precursor contained in the raw material as an additive may include at least one selected from coke, pitch, thermosetting resin, and thermoplastic resin. The coke may include petroleum or coal tar pitch derived cokes, and the pitch may include petroleum pitch, coal pitch or mixtures thereof. The pitch may include an isotropic pitch, mesophase pitch, or a mixture thereof. The resin used as the carbon precursor may be a thermosetting resin, a thermoplastic resin or a mixture thereof. The thermosetting resin may be an epoxy resin, a polyester resin, a phenol resin, an alkyd (unsaturated polyester) resin, a polyimide resin, a vinyl ester resin, a polyurethane resin, a polyisocyanurate resin, or a mixture thereof, and the like. The resin is polyethylene resin, polypropylene resin, polyvinyl alcohol resin, polyvinylidene chloride resin, polyethylene terephthalate resin, polyester resin, polystyrene resin, polymethyl methacrylate resin, polyvinyl chloride resin, ABS (Acrylonitrile Butadien Stylene) Resins, polyamide resins, polycarbonate resins, polyoxymethylene resins, acrylic resins, polyvinylsulfide resins, polyetheretherketone resins, polytetrafluoroethylene resins, or mixtures thereof, but are not limited thereto. Although not particularly limited, the carbonization yield of the resin used as the carbon precursor may be 10% or more, specifically 30 to 90%, and more specifically 40 to 90%. In this case, when using a carbon-based resin precursor having a carbon yield of 40% or less, the carbon precursor may also serve as a pore-forming agent. As described above, carbon (pyrolysis carbon) generated by pyrolysis of the carbon precursor may play a role of a conductive material and a binder binding between the active material, and may also play a role of an active material involved in charge and discharge reactions. .
이때, 열분해 탄소는 탄소 전구체로부터 유래하는 탄소로 한정되어 해석되기 보다는, 소결체 제조를 위한 열처리나 필요시 이와 독립적으로 수행되는 열처리 공정에 의해 기공 형성제나 유기 바인더등의 첨가제로부터 유래하는 잔류 탄소 또한 포함하는 것으로 해석될 수 있다. In this case, pyrolytic carbon is not limited to carbon derived from a carbon precursor, but also includes residual carbon derived from an additive such as a pore-forming agent or an organic binder by a heat treatment for producing a sintered body or a heat treatment process performed independently if necessary. Can be interpreted as
첨가제를 함유하는 원료를 이용하여 활물질 벌크를 제조하는 구체적인 일 예로, 활물질 벌크 제조 단계는 입자상의 전극 활물질 및 탄소 전구체를 포함하는 원료를 가압 성형하여 성형체를 제조하는 단계; 및 상기 성형체를 열처리하여 상기 탄소 전구체를 탄소로 열분해하는 단계;를 포함할 수 있다. 이때, 전극 활물질 코어는 양극활물질 또는 음극활물질일 수 있다.As a specific example of manufacturing an active material bulk using a raw material containing an additive, the active material bulk manufacturing step may include pressing a raw material including a particulate electrode active material and a carbon precursor to prepare a molded article; And pyrolysing the carbon precursor to carbon by heat treating the molded body. In this case, the electrode active material core may be a positive electrode active material or a negative electrode active material.
제조되는 전극의 용도, 전극활물질의 전기적 특성등, 목적하는 기공률등을 고려하여, 원료에 함유되는 첨가제의 종류나 함량등이 조절될 수 있음은 물론이다. In consideration of the intended porosity, such as the use of the electrode to be prepared, the electrical properties of the electrode active material, and the like, the type and content of the additive contained in the raw material can of course be adjusted.
원료가 도전재를 함유하는 경우, 원료는 전극 활물질 100 중량부 기준 1 내지 30중량부, 구체예로 1 내지 20중량부의 도전재를 함유할 수 있으나, 반드시 이에 제한되는 것은 아니다.When the raw material contains the conductive material, the raw material may contain 1 to 30 parts by weight, specifically, 1 to 20 parts by weight of the conductive material based on 100 parts by weight of the electrode active material, but is not limited thereto.
원료가 바인더를 함유하는 경우, 원료는 전극 활물질 100 중량부 기준 0.5 내지 10 중량부의 바인더를 함유할 수 있으나, 반드시 이에 제한되는 것은 아니다.When the raw material contains the binder, the raw material may contain 0.5 to 10 parts by weight of the binder based on 100 parts by weight of the electrode active material, but is not limited thereto.
원료가 탄소 전구체를 함유하는 경우, 원료는 전극 활물질 100 중량부 기준 1 내지 30 중량부, 구체예로 1 내지 25중량부의 탄소 전구체를 함유할 수 있으나, 반드시 이에 제한되는 것은 아니다.When the raw material contains the carbon precursor, the raw material may contain 1 to 30 parts by weight, specifically, 1 to 25 parts by weight of the carbon precursor based on 100 parts by weight of the electrode active material, but is not limited thereto.
원료가 기공형성제를 함유하는 경우, 원료는 전극 활물질 100 중량부 기준 1 내지 20 중량부의 기공형성제를 함유할 수 있으나, 반드시 이에 제한되는 것은 아니다. When the raw material contains a pore-forming agent, the raw material may contain 1 to 20 parts by weight of the pore-forming agent based on 100 parts by weight of the electrode active material, but is not necessarily limited thereto.
그러나, 원료가 도전재, 바인더, 탄소 전구체 및/또는 기공형성제를 함유하지 않을 수 있음은 물론이며, 단적인 일 예로, 활물질 벌크는 전극활물질로 이루어질 수 있다.However, the raw material may not contain a conductive material, a binder, a carbon precursor, and / or a pore-forming agent. Of course, the bulk of the active material may be made of an electrode active material.
또한, 필요시, 원료는 바인더 내지 탄소 전구체의 용매나 분산을 위한 분산매를 더 함유할 수 있으나, 본 발명이 용매나 분산매의 사용 유무나 구체적 함량에 의해 한정될 수 없음은 물론이다.In addition, if necessary, the raw material may further contain a dispersion medium for the solvent or dispersion of the binder to the carbon precursor, of course, the present invention is not limited by the use or the specific content of the solvent or dispersion medium.
구체적으로, 원료의 혼합이 습식 혼합인 경우 용매나 분산매를 사용할 수 있으며, 건식 혼합인 경우 용매나 분산매를 사용하지 않을 수 있다. Specifically, when the mixing of the raw materials is wet mixing, a solvent or a dispersion medium may be used, and in the case of dry mixing, a solvent or a dispersion medium may not be used.
원료에 함유되는 용매(수계 용매 또는 유기용매)는 이차전지 분야에서 양극 또는 음극 활물질 슬러리 제조시 통상적으로 사용하는 수계 용매 또는 유기 용매이면 족하다. 구체적으로, 수계 용매는 물, 이소프로필알코올, 프로판올, 메탄올, 에탄올등을 포함하는 용매를 들 수 있으며, 유기 용매는 아세톤, N-메틸-2-피롤리돈(NMP), 디메틸포름아마이드, 디메틸아세트아마이드, 클로로포름, 디클로로메탄, 트리클로로에틸렌, 노르말헥산, N,N-디메틸아미노프로필아민, 에틸렌옥사이드, 테트라히드로퓨란 또는 이들의 혼합 용매등을 들 수 있으나, 이에 한정되는 것은 아니다.The solvent (aqueous solvent or organic solvent) contained in the raw material may be any aqueous solvent or organic solvent that is commonly used in the production of a positive electrode or negative electrode active material slurry in the secondary battery field. Specifically, the aqueous solvent may include a solvent including water, isopropyl alcohol, propanol, methanol, ethanol and the like, and the organic solvent may be acetone, N-methyl-2-pyrrolidone (NMP), dimethylformamide, dimethyl Acetamide, chloroform, dichloromethane, trichloroethylene, normal hexane, N, N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran, or a mixed solvent thereof, and the like, but are not limited thereto.
본 발명의 일 실시예에 따른 제조방법에 있어, 활물질 벌크는 원료에 물리적 힘을 인가하여 제조된 성형체이거나, 성형체에 열을 인가하여 제조된 소결체일 수 있다. In the manufacturing method according to an embodiment of the present invention, the active material bulk may be a molded body manufactured by applying a physical force to the raw material, or may be a sintered body manufactured by applying heat to the molded body.
성형체는 전극 활물질이 소성 변형되며 서로 결착되며 일정한 강도를 가질 수 있으며, 소결체는 소결에 의해 일체의 물로 결착이 이루어지며 일정한 강도를 가질 수 있다. 이에, 성형체 또는 소결체인 활물질 벌크는 유기 바인더를 함유하지 않는 바인더-프리(binder-free) 활물질 벌크일 수 있으며, 이에 따라, 활물질 막 또한 바인더-프리 활물질 막이 제조될 수 있다. 그러나, 이는 성형체나 소결체인 활물질 벌크를 제조한 후 이를 잘라 활물질 막을 제조하는 본 발명의 일 실시예에 따른 제조방법에 의해 가능한 일 예이며, 본 발명이 바인더-프리 활물질 벌크가 바인더-프리 활물질 막으로 제한되는 것은 아니다. The molded body may be plastically deformed and bound to each other and have a constant strength, and the sintered body may be bound to integral water by sintering and may have a constant strength. Accordingly, the active material bulk, which is a molded or sintered body, may be a binder-free active material bulk containing no organic binder, and thus an active material film and a binder-free active material film may be prepared. However, this is an example possible by the manufacturing method according to an embodiment of the present invention for producing an active material film which is a molded body or a sintered body and then cut it, and the present invention is a binder-free active material bulk binder-free active material film It is not limited to.
성형체인 활물질 벌크를 제조하고자 하는 경우, 활물질 벌크의 제조단계는 원료의 1방향, 2방향 또는 등방향 압축 성형에 의해 제조될 수 있다. 구체적으로, 성형체인 활물질 벌크 제조 단계는 원료를 혼합하는 단계; 및 혼합된 원료를 가압(압축) 성형하는 단계;를 포함할 수 있다. In the case of preparing the active material bulk which is a molded article, the step of preparing the active material bulk may be prepared by one-way, two-way, or isodirectional compression molding of the raw material. Specifically, the bulk manufacturing step of the active material, which is a molded body, may include mixing raw materials; And pressing (compressing) molding the mixed raw materials.
원료의 혼합은 건식 또는 습식 혼합일 수 있다. 건식 혼합은 용매(또는 분산매)를 사용하지 않고 입자상의 전극 활물질을 탄소 전구체등과 같은 첨가제와 혼합하여 수행될 수 있다. 습식 혼합의 경우, 용매나 분산매를 사용하나, 종래의 활물질 슬러리 제조 공정과는 달리 고형분의 함량이 매우 높은 상태(일 예로, 고형분 60중량% 이상, 구체예로 고형분 70중량% 이상)에서 혼합을 수행할 수 있어, 용매나 분산매로 사용되는 수계 용매 내지 유기용매의 사용량을 현저하게 감소시킬 수 있다. 습식 혼합이 수행되는 경우 성형 전 또는 성형 후 용매(또는 분산매)를 휘발 제거하는 건조 단계가 더 수행될 수 있다. The mixing of the raw materials may be dry or wet mixing. Dry mixing may be performed by mixing the particulate electrode active material with an additive such as a carbon precursor or the like without using a solvent (or a dispersion medium). In the case of wet mixing, a solvent or a dispersion medium is used, but unlike a conventional active material slurry manufacturing process, the mixing is performed in a state where the solid content is very high (for example, solid content of 60% by weight or more, concrete weight of 70% by weight or more). It can be carried out, it is possible to significantly reduce the amount of the aqueous solvent to the organic solvent used as a solvent or a dispersion medium. When wet mixing is performed, a drying step may be further carried out to volatilize the solvent (or dispersion medium) before or after molding.
압축 성형은 목적하는 벌크의 3차원 입체 형상 및 크기에 대응하는 내부 수용 공간을 갖는 몰드에 혼합된 원료를 투입한 후, 1축 가압(pressing), 2축 가압 또는 등방향 가압을 통해 원료에 압축력을 인가함으로써 수행될 수 있다. 성형시 가해지는 압력은 원료에 함유된 물질의 종류와 소결 특성, 설계된 기공률등을 고려하여 적절히 조절되면 무방하다. 구체예로, 성형은 10 내지 120MPa 압력에서 수행될 수 있으나, 이에 한정되지 않는다.Compression molding is performed by inserting a mixed raw material into a mold having an internal receiving space corresponding to a three-dimensional solid shape and size of a desired bulk, and then compressing the raw material by uniaxial pressing, biaxial pressing, or isostatic pressing. It can be performed by applying. The pressure applied during molding may be properly adjusted in consideration of the type of material contained in the raw material, the sintering characteristics, and the designed porosity. In an embodiment, the molding may be performed at a pressure of 10 to 120 MPa, but is not limited thereto.
성형체인 활물질 벌크는 전극 활물질이 소성 변형 가능한 물질, 구체예로, 음극 활물질, 실질적인 일 예로, 천연 흑연 및 인조 흑연에서 하나 이상 선택되는 탄소계 음극 활물질을 함유할 수 있다. 이러한 경우, 가압(압축) 성형시 전극 활물질의 소성 변형이 발생함에 따라, 최소한의 첨가제를 사용하여 프리 스탠딩 가능한 3차원 입체가 제조될 수 있다. 또한, 이와 독립적으로, 압축에 의해 전극 활물질이 소성 변형되며 압력 인가 방향으로 눌린 형태, 즉, 눌린 입자로 그 형상이 변형되며 눌린 입자(전극 활물질 입자)에 의해 활물질 벌크에 전극 활물질의 배향성이 형성될 수 있다. 이러한 전극 활물질의 배향성은 전극의 충전 및 방전 율특성을 향상시킬 수 있어 유리하다. 이러한 측면에서 활물질 벌크가 성형체인 경우, 몰드에 혼합된 원료를 투입한 후 1축 가압 또는 2축 가압에 의해 성형체를 제조하는 것이 좋다. The active material bulk, which is a molded article, may contain a material capable of plastically deforming the electrode active material, in particular, a negative electrode active material, substantially one or more carbon-based negative electrode active material selected from natural graphite and artificial graphite. In this case, as the plastic deformation of the electrode active material occurs during the pressure (compression) molding, a free standing three-dimensional solid body can be manufactured using minimal additives. In addition, the electrode active material is plastically deformed by compression and pressed in the pressure application direction, that is, its shape is deformed into pressed particles, and the orientation of the electrode active material is formed in the active material bulk by the pressed particles (electrode active material particles). Can be. The orientation of the electrode active material is advantageous because it can improve the charge and discharge rate characteristics of the electrode. In this aspect, when the bulk of the active material is a molded article, it is preferable to prepare the molded article by uniaxial pressurization or biaxial pressurization after inputting the mixed raw material into the mold.
그러나, 본 발명이 소성 변형에 의해서만 배향성이 야기되는 것으로 한정되어 해석되어서는 안된다. 일 예로, 전극 활물질이 인편상의 흑연계 활물질등과 같이 판형이나 플레이크 형상인 경우, 성형을 위해 몰드에 원료를 투입하고 팩킹(packing)하는 과정에서 이미 배향성이 형성될 수도 있으며 벌크제조단계에서 액상 혼련 상태에서 자기장을 가해 배향성을 제어할 수 도 있다. 또한, 음극 활물질이 인편상의 흑연계 활물질과 구형의 천연흑연을 모두 함유하는 경우, 인편상의 흑연계 활물질은 성형을 위한 압축력에 수직 방향으로 배향될 수 있고, 구형 천연흑연은 소성변형을 하며 압축력에 수직 방향으로 배향될 수 있다. However, the present invention should not be construed as being limited only to the orientation caused by plastic deformation. For example, when the electrode active material is plate-like or flake-like, such as a flake graphite active material, the orientation may be already formed in the process of adding and packing the raw material into the mold for molding and liquid kneading in the bulk manufacturing step. In this state, a magnetic field may be applied to control the orientation. In addition, when the negative electrode active material contains both flaky graphite-based active material and spherical natural graphite, the flaky graphite-based active material may be oriented in a direction perpendicular to the compressive force for forming, and spherical natural graphite undergoes plastic deformation and It can be oriented in the vertical direction.
도 1은 전극 활물질이 소성 변형 가능한 물질, 구체예로, 탄소계 음극 활물질인 경우, 성형 전의 탄소계 음극 활물질 입자(110)를 함유하는 원료(100)를 압축 성형하여 제조된 성형체(200) 및 성형체(200) 내 탄소계 음극 활물질의 눌린 입자(210)를 도시한 도면이다. 도 1에 도시한 일 예와 같이, 압축 성형에 의해 탄소계 음극 활물질 입자(110)들이 일정 방향으로 변형된 눌린 입자(210)들이 형성될 수 있으며, 이러한 눌린 입자들에 의해 성형체(200)에는 전극 활물질 입자들의 배향성(도 1의 화살표로 도시)이 형성될 수 있다.1 is a material that can plastically deform an electrode active material, in particular, a carbon-based negative electrode active material, a molded body 200 manufactured by compression molding the raw material 100 containing the carbon-based negative electrode active material particles 110 before molding and It is a figure which shows the pressed particle 210 of the carbon-based negative electrode active material in the molded object 200. As illustrated in FIG. 1, the pressed particles 210 in which the carbon-based negative electrode active material particles 110 are deformed in a predetermined direction by compression molding may be formed, and the molded particles 200 may be formed by the pressed particles. The orientation of the electrode active material particles (shown by the arrow in FIG. 1) may be formed.
본 발명의 일 실시예에 따른 제조방법에 의해, 활물질 벌크가 제조된 후, 이를 절단하여 집전체에 부착되는 활물질 막이 제조됨에 따라, 전극 활물질의 배향성을 갖는 활물질 벌크를 절단하는 절단 방향에 따라, 활물질 막의 두께 방향으로의 배향성(전극 활물질 입자들의 배향 방향)이 제어될 수 있다. By the manufacturing method according to an embodiment of the present invention, after the active material bulk is manufactured, according to the cutting direction for cutting the active material bulk having the orientation of the electrode active material, as the active material film is cut and attached to the current collector, The orientation in the thickness direction of the active material film (the orientation direction of the electrode active material particles) can be controlled.
이러한 전극 활물질 막의 배향성은 슬러리의 도포 및 압연이라는 종래의 슬러리 기반 전극 제조 기술에서는 실질적으로 구현되기 어려운 것이다. 이는 활물질 슬러리가 집전체에 도포된 후 압연이 수행됨에 따라, 활물질의 소성 변형(plastic deformation, 영구 변형)이 발생하는 경우, 소성 변형된 전극 활물질 입자의 배향성은 집전체과 활물질층의 계면 방향(활물질층 표면의 면내 방향과 동일)에 평행한 방향으로 국한될 수 밖에 없기 때문이다. The orientation of such an electrode active material film is substantially difficult to realize in the conventional slurry-based electrode manufacturing technique of coating and rolling slurry. This is because when the plastic deformation (permanent deformation) of the active material occurs as the rolling is performed after the active material slurry is applied to the current collector, the orientation of the plastically deformed electrode active material particles is the interface direction between the current collector and the active material layer (active material). This is because it is limited to the direction parallel to the in-plane direction of the layer surface).
그러나, 도 2에 도시한 일 예와 같이, 단지 전극 활물질의 배향성을 갖는 활물질 벌크(200)의 절단 방향(도 2의 CD)을 조절하는 것만으로, 활물질 막(300)의 두께 방향을 기준한 전극 활물질의 배향 방향이 제어될 수 있다. However, as in the example shown in FIG. 2, only by adjusting the cutting direction (CD of FIG. 2) of the active material bulk 200 having the orientation of the electrode active material, the thickness direction of the active material film 300 is referred to. The orientation direction of the electrode active material may be controlled.
특히, 도 2의 하부에 도시한 예와 같이, 활물질 벌크(200)의 절단 방향(CD)이 눌린 입자의 눌려진 방향과 평행한, 즉, 눌린 입자의 눌린 면과 수직인 방향인 경우, 활물질 막(300)의 두께 방향과 활물질 입자(눌린 입자)의 배향 방향이 실질적으로 평행하여, 입자와 입자 사이의 공간을 통한 전해액의 함침 및 리튬 이온과 같이 충 방전에 관여하는 이온의 확산이 보다 원활하게 이루어질 수 있다. In particular, as shown in the lower portion of FIG. 2, when the cutting direction CD of the active material bulk 200 is parallel to the pressed direction of the pressed particles, that is, the direction perpendicular to the pressed surface of the pressed particles, the active material film The thickness direction of 300 and the orientation direction of the active material particles (pressed particles) are substantially parallel, so that the impregnation of the electrolyte through the space between the particles and the particles and the diffusion of ions involved in charge and discharge, such as lithium ions, are more smoothly performed. Can be done.
이와 달리, 활물질 벌크는 소결체일 수 있으며, 원료(또는 성형체)에 열을 인가하여 소결체인 활물질 벌크가 제조될 수 있다. 구체적으로, 활물질 벌크가 소결체인 경우, 본 발명의 일 실시예에 따른 제조방법은 원료를 몰드에 투입하고 성형하여 성형체를 제조하는 단계; 성형체에 열을 인가하여 소결체를 제조하는 단계;를 포함할 수 있다. 이때, 성형체 제조 단계과 소결체 제조 단계가 동시에 수행될 수도 있다. 즉, 원료에 열과 함께 물리적 힘이 동시 인가되어 소결체가 제조될 수도 있다. 열과 함께 기계적 힘(물리적 힘)이 인가되는 구체 예로, 열간 가압 소결등을 들 수 있다. 열의 인가는 통상의 퍼니스를 이용한 열처리를 통해 수행될 수 있으나, 이에 한정되지 않으며, SPS(spark plasma sintering)등 소결체를 제조하기 위해 사용하는 것으로 알려진 어떠한 방법을 이용하여 수행되어도 무방하다. 이때, 열처리(열의 인가)시 구체 전극 활물질의 종류를 고려하여 분위기가 제어될 수 있음은 물론이다. 일 예로, 전극 활물질이 탄소계 활물질을 포함하는 경우, 질소, 아르곤등의 비산화성 분위기에서 열처리가 수행될 수 있으며, 전극 활물질이 산화물계 활물질을 포함하는 경우 대기등과 같은 함 산소 분위기에서 열처리가 수행될 수 있다. Alternatively, the active material bulk may be a sintered body, and an active material bulk, which is a sintered body, may be manufactured by applying heat to a raw material (or a molded body). Specifically, when the bulk of the active material is a sintered body, the manufacturing method according to an embodiment of the present invention comprises the steps of preparing a molded body by putting the raw material into the mold and molding; Producing a sintered body by applying heat to the molded body; may include. At this time, the molded article manufacturing step and the sintered body manufacturing step may be performed at the same time. That is, the sintered compact may be manufactured by simultaneously applying heat and physical force to the raw material. Specific examples of applying mechanical force (physical force) together with heat include hot press sintering and the like. The application of heat may be performed by heat treatment using a conventional furnace, but is not limited thereto, and may be performed using any method known to be used to manufacture a sintered body such as spark plasma sintering (SPS). At this time, the atmosphere may be controlled in consideration of the type of the specific electrode active material during heat treatment (application of heat). For example, when the electrode active material includes a carbon-based active material, heat treatment may be performed in a non-oxidizing atmosphere such as nitrogen and argon. When the electrode active material includes an oxide-based active material, the heat treatment may be performed in an oxygen-containing atmosphere such as an atmosphere. Can be performed.
소결체인 활물질 벌크의 제조시 원료의 전극 활물질은 양극 활물질 또는 음극 활물질일 수 있다. 일 예로, 소결체인 활물질 벌크를 제조하고자 하는 경우, 원료의 전극 활물질은 양극 활물질 또는 비 탄소계 음극 활물질을 포함할 수 있다. 소결체는 열 인가(구체 예로, 열처리)에 의해 전극 활물질 입자간 입계(grain boundary)나 넥(neck)이 형성되며 입자상의 전극 활물질이 일체로 결착(융합)된 상태일 수 있다. 또는 이와 달리 소결체는 활물질 입자들이 열분해 탄소(탄소 전구체 유래 열분해 탄소)에 의해 서로 결착된 상태일 수 있다. 활물질 벌크가 전극 활물질의 소결체인 경우, 전극 활물질 입자의 평균 크기, 분포 및 소결 정도에 의해 기공 구조나 기공률등이 용이 제어될 수 있다. The electrode active material of the raw material in the production of the active material bulk, which is a sintered body may be a positive electrode active material or a negative electrode active material. For example, when manufacturing an active material bulk that is a sintered body, the electrode active material of the raw material may include a positive electrode active material or a non-carbon negative electrode active material. The sintered body may be in a state in which grain boundaries or necks are formed between the electrode active material particles by heat application (specifically, for example, heat treatment) and the particulate electrode active material is integrally bound (fused). Alternatively, the sintered compact may be in a state in which active material particles are bound to each other by pyrolysis carbon (pyrolysis carbon derived from a carbon precursor). When the bulk of the active material is a sintered body of the electrode active material, the pore structure or the porosity can be easily controlled by the average size, distribution, and sintering degree of the electrode active material particles.
구체예로, 활물질 벌크는 원료의 전극 활물질 입자가 넥(neck)을 형성하며 서로 결착된 소결체일 수 있다. 도 3은 원료에서 서로 인접하는 두 전극 활물질 입자(110)를 기준하여 넥(neck, 도 3에서 화살표로 도시)에 의해 서로 결착된 활물질 입자(210)를 도시한 도면이다. 알려진 바와 같이, 소결과정은 초기, 중기, 말기로 나뉘며, 소결 초기 단계(initial stage)는 입자와 입자 사이에 넥(neck)이 형성되는 단계이다. 원료에 함유되는 첨가제의 종류와 함량에 따라 어느 정도 달라질 수 있으나, 소결 초기 단계는 소결 수축이 약 3-10%(부피%), 구체적으로 3-7%에 이르는 단계에 해당할 수 있다소결 초기 단계에서 성형체 내 기공들은 실질적으로 대부분 열린 기공(open pore)으로 존재하며, 주로 입자와 입자의 접촉점으로 주로 물질 이동(확산)이 발생하며 입자와 입자 사이가 넥으로 서로 연결되는 단계이다. 이에 따라, 소결체가 전극 활물질 입자간 넥이 형성된 소결 초기 단계의 산물인 경우, 절단, 이송, 부착등의 공정 중 안정적인 핸들링 및 공정 수행이 가능한 기계적(물리적) 강도를 가지면서도 다량의 열린 기공을 함유할 수 있어 전해액 함침 및 전기화학적 반응 면적 향상 측면에서 매우 유리하다. 또한, 절단막이 매우 두꺼운 후막 형태라 할지라도 절단 방향과 무관하게 다량의 열린 기공 채널들이 절단막을 관통하는 구조를 가질 수 있어, 절단막의 두께 방향으로 균일하게 전해액이 침투할 수 있다.In an embodiment, the active material bulk may be a sintered body in which electrode active material particles of a raw material form a neck and are bound to each other. FIG. 3 illustrates active material particles 210 bound to each other by a neck (shown by an arrow in FIG. 3) based on two electrode active material particles 110 adjacent to each other in a raw material. As is known, the sintering process is divided into an initial stage, a middle stage, and a final stage, and an initial stage of sintering is a stage in which a neck is formed between the particles. Although it may vary to some extent depending on the type and content of the additives contained in the raw material, the initial stage of sintering may correspond to a stage of sintering shrinkage of about 3-10% (vol%), specifically 3-7%. In the step, the pores in the molded body are substantially mostly open pores, and mainly a mass transfer (diffusion) occurs at the contact point of the particles and the particles, and the particles and the particles are connected to each other by a neck. Accordingly, when the sintered body is a product of the initial stage of sintering in which the neck between the electrode active material particles is formed, it contains a large amount of open pores while having a mechanical (physical) strength that enables stable handling and process performance during cutting, conveying, and attaching processes. It can be very advantageous in terms of impregnation of electrolyte solution and improvement of electrochemical reaction area. In addition, even when the cut film is in the form of a very thick thick film, a large amount of open pore channels may pass through the cut film regardless of the cutting direction, so that the electrolyte solution may uniformly penetrate in the thickness direction of the cut film.
그러나, 본 발명에서 소결체가 전극활물질 입자간 넥으로 연결된 상태로 한정되어 해석될 수 없으며, 앞서 상술한 바와 같이, 성형체나 원료에 열, 구체적으로 물질 이동이 가능한 열 에너지, 실질적으로 300℃이상의 열처리, 보다 실질적으로 500℃ 이상의 열처리, 보다 더 실질적으로 600℃ 이상의 열처리가 수행되어 수득되는 생성물로 해석될 수 있다. However, in the present invention, the sintered body is not limited to the state connected to the neck between the electrode active material particles, and can not be interpreted. As described above, heat to the molded body or the raw material, specifically, thermal energy capable of moving a substance, and heat treatment of substantially 300 ° C. or more It can be interpreted as a product obtained by performing a heat treatment more substantially 500 ° C. or more and even more substantially 600 ° C. or more.
또한, 원료의 구체 물질에 따라, 소결체 제조를 위한 열 인가에 의해 또는 필요시 소결체 제조 후 별도의 독립된 열처리 공정에 의해, 기공 형성제의 분해 제거(burn-out), 도전재와 활물질의 결착(도전재의 용융 결착을 포함함), 바인더의 분해 제거, 바인더의 탄화, 전극 활물질 전구체의 전극활물질로의 전환, 탄소 전구체의 탄소(열분해 탄소)로의 전환, 및/또는 열분해 탄소의 흑연화 처리등이 이루어질 수 있다. In addition, depending on the specific material of the raw material, by the application of heat for the manufacture of the sintered body or, if necessary, by a separate independent heat treatment process after the manufacture of the sintered body, burn-out of the pore-forming agent, binding of the conductive material and the active material ( Including melting and binding of conductive materials), decomposition and removal of binders, carbonization of binders, conversion of electrode active material precursors to electrode active materials, conversion of carbon precursors to carbon (pyrolytic carbon), and / or graphitization of pyrolytic carbon, and the like. Can be done.
일 예로, 음극활물질이 하드카본이나 소프트카본등 같은 소성 변형이 어려운 물질인 경우, 또는 필요시 소성 변경 가능한 천연 흑연과 같은 물질이라 하더라도, 입자상의 전극활물질(하드카본, 소프트카본, 천연 흑연등)과 탄소 전구체를 함유하는 원료를 성형하여 성형체를 제조한 후, 열을 인가하여 탄소 전구체를 탄소로 전환시킴으로써, 소결체 형태의 활물질 벌크를 제조할 수 있다. 이러한 경우, 소결체는 입자상의 전극활물질들은 적어도, 탄소 전구체로부터 전환된 탄소(열분해 탄소)에 의해 결착된 상태일 수 있다. For example, when the negative electrode active material is a material that is difficult to plastically deform, such as hard carbon or soft carbon, or a material such as natural graphite that can be plastically changed if necessary, particulate electrode active material (hard carbon, soft carbon, natural graphite, etc.) After forming a molded article by molding a raw material containing a carbon precursor with a carbon precursor, the bulk of the active material in the form of a sintered compact can be prepared by applying heat to convert the carbon precursor into carbon. In this case, the sintered body may be in a state where particulate electrode active materials are bound by at least carbon (pyrolysis carbon) converted from a carbon precursor.
즉, 활물질 벌크는 입자상의 활물질 및 입자상의 활물질을 결착시키는 열분해 탄소를 포함할 수 있으며, 이러한 활물질 벌크로부터 제조되는 활물질 막 또한 입자상의 활물질 및 전극 활물질 입자간을 결착시키는 열분해 탄소를 포함할 수 있다.That is, the active material bulk may include particulate active material and pyrolytic carbon binding the particulate active material, and the active material film prepared from such active material bulk may also include pyrolytic carbon binding between the particulate active material and the electrode active material particles. .
종래 슬러리 기반 전극 제조 기술의 경우, 입자들의 슬러리를 집전체에 도포하여 활물질 '합제층'이라는 층 구조를 유지하여야 함에 따라, 활물질층의 전극 활물질 분율을 저해하며 전기적 특성을 감소시킴에도 불구하고 바인더의 사용이 불가피하였다. In the conventional slurry-based electrode manufacturing technology, a slurry of particles must be applied to a current collector to maintain a layer structure called an active material 'mixing layer', thereby inhibiting the electrode active material fraction of the active material layer and reducing the electrical properties despite the decrease in electrical properties. The use of was inevitable.
그러나, 본 발명의 일 실시예에 따른 제조방법의 경우, 전극 활물질 입자간 입계나 넥 형성 또는 탄소 전구체로부터 전환된 탄소(열분해 탄소)에 의한 결착등에 의해 프리-스탠딩 가능한 소결체가 제조될 수 있다. However, in the manufacturing method according to an embodiment of the present invention, a free-standable sintered body may be manufactured by grain boundaries between electrode active material particles, neck formation, or binding by carbon (pyrolysis carbon) converted from a carbon precursor.
이에 따라, 활물질 벌크는 바인더-프리 소결체일 수 있으며, 이를 절단하여 제조되는 활물질 막 또한 바인더를 함유하지 않는 바인더-프리 막일 수 있다. 이때, 바인더-프리는 유기 바인더를 함유하지 않는 것으로 해석될 수 있다. 실험적으로, 바인더-프리는 Ar등과 같은 불활성 분위기에서 분당 5℃의 승온속도로 600℃까지 승온하여 전극의 중량 감소율을 측정할 때, 중량 감소율이 2% 이내, 실질적으로 1% 이내, 보다 실질적으로0.5% 이내, 보다 더 실질적으로 오차범위 내로 중량 감소가 발생하지 않는 경우를 의미할 수 있다. Accordingly, the active material bulk may be a binder-free sintered body, and the active material film prepared by cutting it may also be a binder-free film containing no binder. At this time, the binder-free may be interpreted as containing no organic binder. Experimentally, when binder-free is heated up to 600 ° C. at an elevated temperature rate of 5 ° C. per minute in an inert atmosphere such as Ar or the like, the weight loss rate is less than 2%, substantially less than 1%, and more substantially, It may mean that the weight loss does not occur within 0.5%, more substantially within the error range.
탄소 전구체로부터 유래하는 탄소, 구체적으로 열분해 탄소는 전도성을 향상시키기 위한 도전재의 역할, 입자상의 활물질을 결착시키는 역할을 수행할 수 있으며, 리튬의 삽입이 가능한 활물질로도 작용할 수 있다. Carbon derived from the carbon precursor, specifically, pyrolytic carbon may serve as a conductive material to improve conductivity, bind a particulate active material, and may also function as an active material capable of inserting lithium.
이에, 바인더-프리는 유기 바인더-프리로 해석될 수 있으며, 바인더-프리 활물질 벌크(바인더-프리 성형체 또는 바인더-프리 소결체)는 유기 바인더를 함유하지 않는 성형체나 소결체를 의미할 수 있다. 구체예로, 바인더-프리 소결체는 활물질로 이루어진 소결체; 활물질 및 잔류 탄소(유기 바인더 분해등에 의한 잔류 탄소)로 이루어진 소결체; 활물질 및 도전재로 이루어진 소결체; 활물질, 도전재 및 잔류탄소로 이루어진 소결체; 활물질 및 탄소 전구체 유래 탄소로 이루어진 소결체; 활물질, 탄소 전구체 유래 탄소 및 잔류 탄소로 이루어진 소결체; 활물질, 도전재 및 탄소 전구체 유래 탄소로 이루어진 소결체; 또는 활물질, 도전재, 탄소 전구체 유래 탄소 및 잔류 탄소로 이루어진 소결체 등을 포함할 수 있다. Thus, the binder-free may be interpreted as an organic binder-free, and the binder-free active material bulk (binder-free molded body or binder-free sintered body) may mean a molded or sintered body containing no organic binder. In one embodiment, the binder-free sintered compact includes a sintered compact composed of an active material; A sintered body made of an active material and residual carbon (residual carbon by organic binder decomposition, etc.); A sintered body made of an active material and a conductive material; A sintered body composed of an active material, a conductive material and residual carbon; A sintered body made of an active material and carbon derived from a carbon precursor; A sintered body consisting of an active material, carbon precursor-derived carbon, and residual carbon; A sintered body made of an active material, a conductive material, and carbon derived from a carbon precursor; Or an sintered body made of an active material, a conductive material, carbon precursor-derived carbon, and residual carbon.
상술한 바와 같이, 본 발명의 제조방법적 구성에 의해, 활물질 막은 유기 바인더를 함유하지 않는 바인더-프리 막일 수 있다. 이에 한정되는 것은 아니나, 바인더-프리 막인 활물질 막은 전극 활물질로 이루어지거나, 전극 활물질과 도전재로 이루어지거나, 전극 활물질과 결착역할을 하는 탄소로 이루어질 수 있다.As described above, according to the manufacturing method configuration of the present invention, the active material film may be a binder-free film containing no organic binder. Although not limited thereto, the active material film that is a binder-free film may be made of an electrode active material, made of an electrode active material and a conductive material, or made of carbon which binds to the electrode active material.
그러나, 본 발명의 제조방법적 구성에 의해 바인더-프리 활물질 막이 제조 가능한 것이며, 필요시, 본 발명의 활물질 막이 유기 바인더를 함유할 수 있음은 물론이며, 본 발명이 유기 바인더를 함유하는 활물질 막이나 유기 바인더를 함유하는 활물질 벌크를 배제하는 것으로 해석되어서는 안 된다. However, the binder-free active material film can be manufactured by the manufacturing method structure of this invention, and if necessary, the active material film of this invention can contain an organic binder, Of course, this invention is an active material film containing an organic binder, It should not be interpreted as excluding the bulk of the active material containing the organic binder.
또한, 활물질 벌크가 소결체인 경우, 소결전 성형된 성형체는 유기 바인더를 함유할 수 있음은 물론이며, 소결 과정에서 유기 바인더가 번-아웃(burn-out)되며 바인더-프리 소결체가 제조될 수 있음은 물론이다. 상기 유기 바인더는 번-아웃(burn-out)시 공정 분위기에 따라 잔류탄소를 남길수도 있고 남기지 않을 수 도 있다. 공정 분위기가 산화성 분위기일 경우는 잔류탄소를 남기지 않을 수 있으며, 단지 활물질 입자가 소결전 물리적 일체화를 이룰 수 있도록 보조하는 역할을 하게 된다. 또한, 번아웃 분위기가 비산화성 분위기일 경우 유기 바인더는 잔류탄소를 남기면서 활물질 입자 표면에 탄소를 코팅시키거나 입자와 입자를 잔류탄소로 결착하는 역할을 할 수 있다.In addition, when the bulk of the active material is a sintered body, the molded body before sintering may contain an organic binder, of course, the organic binder may be burned out during the sintering process and a binder-free sintered body may be manufactured. Of course. The organic binder may or may not leave residual carbon depending on the process atmosphere during burn-out. If the process atmosphere is an oxidizing atmosphere, it may not leave residual carbon, and only serves to assist the active material particles to achieve physical integration before sintering. In addition, when the burnout atmosphere is a non-oxidizing atmosphere, the organic binder may serve to coat carbon on the surface of the active material particles or bind particles and particles with residual carbon while leaving residual carbon.
또한, 원료가 입자상의 전극 활물질과 함께, 바인더인 첨가제를 더 포함하는 경우, 소성 변형이 어려운 전극 활물질, 일 예로, 비탄소계 음극 활물질, 하드카본이나 소프트카본, 양극 활물질등 또한 성형체 형태로 활물질 벌크를 제조할 수도 있음은 물론이다. In addition, when the raw material further contains an additive which is a binder together with the particulate electrode active material, an electrode active material which is hard to be plastically deformed, for example, a non-carbon-based negative electrode active material, a hard carbon or soft carbon, a positive electrode active material, and the like, and the active material bulk Of course it can also be prepared.
또한, 원료가 입자상의 전극 활물질과 함께, 도전재인 첨가제를 더 포함하는 경우, 도전재가 균일하게 분산 함입된 활물질 벌크의 제조가 가능하며, 특히, 도전재가 나노구조체를 포함하는 경우, 나노구조체의 네트워크에 의해 연속적인 전류 이동 경로가 형성된 활물질 벌크의 제조가 가능하다. 또한, 활물질 벌크 내에 함유된 도전재는 벌크화를 위해 인가되는 압력 또는 압력과 열에 의해 변형, 압착, 연화 내지 부분 용융되며 도전재간 내지 전극 활물질과 결착된 상태일 수 있다.In addition, when the raw material further contains an additive which is a conductive material together with the particulate electrode active material, it is possible to manufacture the bulk of the active material in which the conductive material is uniformly dispersed and contained, in particular, when the conductive material includes the nanostructure, the network of the nanostructure It is possible to manufacture the bulk of the active material in which the continuous current movement path is formed. In addition, the conductive material contained in the bulk of the active material may be deformed, compressed, softened or partially melted by a pressure or pressure and heat applied for bulking, and may be in a state of being bound between the conductive materials and the electrode active material.
또한, 입자상의 전극활물질이 코어-쉘 구조의 복합 입자인 경우, 복합 입자 자체가 사용될 수도 있으며, 코어 입자(전극활물질 입자)와 쉘의 물질 각각을 이용하여 원료의 혼합 과정에서 코어-쉘 구조의 복합 입자가 제조되도록 할 수 있음은 물론이다.In addition, when the particulate electrode active material is a composite particle having a core-shell structure, the composite particle itself may be used, and the core-shell structure may be used during the mixing of raw materials using the core particles (electrode active material particles) and the materials of the shell. Of course, the composite particles can be made.
실질적인 일 예로, 전극 활물질이 탄소계 음극활물질인 경우, 탄소계 음극활물질 코어-탄소 전구체 쉘의 코어-쉘 복합 입자를 포함하는 원료를 가압 성형하여 성형체를 제조한 후, 열처리를 통해 쉘의 탄소 전구체를 탄소로 전환시켜 활물질 벌크를 제조할 수 있다. 이와 달리, 탄소계 음극활물질 코어 입자 및 탄소 전구체(용융상, 고상 또는 용매에 용해된 용해상)를 포함하는 원료를 혼합한 후 가압 성형하여 성형체를 제조한 후, 열처리를 통해 코어 입자에 코팅된 상태인 탄소 전구체를 탄소로 전환시켜 활물질 벌크를 제조할 수 있다.As a practical example, when the electrode active material is a carbon-based negative electrode active material, the raw material including the core-shell composite particles of the carbon-based negative electrode active material core-carbon precursor shell is molded to prepare a molded body, and then the carbon precursor of the shell through heat treatment. The bulk of the active material can be prepared by converting to carbon. Alternatively, after mixing the raw material including the carbon-based negative electrode active material core particles and the carbon precursor (melt phase, solid phase or dissolved phase dissolved in a solvent) to prepare a molded body by pressure molding, and then coated on the core particles through heat treatment Bulk of the active material may be prepared by converting a carbon precursor in a state into carbon.
상술한 실질적인 일 예에서, 탄소 전구체는 성형체에서 바인더의 역할을 수행할 수 있다. 이러한 경우 탄소 전구체가 열처리에 의해 탄소로 전환된 후에도 활물질들을 서로 결착시키며 전도성 경로를 제공할 수 있어 유리하며, 탄소계 물질로 이루어진 탄소계 활물질 벌크의 제조가 가능하여 유리하다. 또한, 탄소계 전극 활물질로 고가의 구상 흑연 대신 저가의 판상 흑연으로도 탄소계 활물질 벌크를 제조할 수 있는 장점이 있다. 일반적인 전극 제조방식으로 판상흑연을 이용해 전극을 제조할 경우 압연에 의해 집전체와 평행한 방향으로 인편상 흑연이 배향하므로 전극에 수직한 방향으로 전해액 함침이 어려워지거나 속도가 느려지는 현상으로 인해 충방전 율특성이 저하되는 문제가 있다. 그러나 본 발명의 일 실시예에 따른 제조방법을 이용하는 경우, 판상흑연을 이용하여 전극 제조 시 활물질 벌크의 절단 방향을 조절함으로서 전극집전체에 인편상흑연이 수직방향으로 배향성을 가지게 조절할 수 있어 전해액 함침이 용이하도록 할 수 있으며 전지 반응 속도를 향상시킬 수 있다. 또한, 배향을 하면서도 기공형성제 및/또는 기공유지 구조체를 사용하거나, 성형 압력이나 등을 이용하여 기공률 조절을 할 수 있어, 종래 인편상 흑연 사용시의 문제점 해결이 가능하여 상업적으로 유리하다.In one practical example described above, the carbon precursor may serve as a binder in the shaped body. In this case, even after the carbon precursor is converted to carbon by heat treatment, the active materials may be bound to each other and provide a conductive path, and the carbon-based active material bulk made of a carbon-based material may be advantageous. In addition, there is an advantage in that the carbon-based active material bulk can be produced using low-cost plate-shaped graphite instead of expensive spherical graphite as the carbon-based electrode active material. In the case of manufacturing electrodes using plate graphite in the general electrode manufacturing method, since the flaky graphite is oriented in a direction parallel to the current collector by rolling, charging and discharging due to a phenomenon in which electrolyte impregnation becomes difficult or speed is slow in the direction perpendicular to the electrode There is a problem that the rate characteristic is lowered. However, when using the manufacturing method according to an embodiment of the present invention, by controlling the cutting direction of the bulk of the active material when the electrode manufacturing using plate-like graphite, the flaky graphite in the electrode current collector can be adjusted to have the orientation in the vertical direction impregnated with the electrolyte This can be facilitated and the battery reaction speed can be improved. In addition, the porosity can be adjusted by using a pore-forming agent and / or a common-coated structure, or by using a molding pressure or the like, while aligning, and thus, it is possible to solve problems in the use of conventional flaky graphite, which is commercially advantageous.
기공유지 구조체는 기공형성제와 구분되는 개념으로서 판상이 아니며 판상흑연 대비 적어도 1/2 이하의 평균입경을 나타내는 활물질 입자로서 판상입자의 사이에 분산되어 위치함으로써 판상흑연이 면대 면으로 완전히 붙어 기공률이 작을 경우, 판상흑연 입자와 입자의 면 사이에 위치하여 면과 면을 공간을 띄워주는 역할을 하는 활물질을 의미할 수 있다.. 구체 예로는 하드카본, 소프트카본, 조립화 인조흑연, 무정형 입자형태의 인조흑연, MCMB(mesocarbon microbead), 구형 천연흑연, Li 4Ti 5O 12등의 익히 알려진 음극활물질이면 가능하다. The pore-forming structure is a concept that is distinguished from the pore-forming agent, and is not plate-shaped, but is an active material particle having an average particle diameter of at least 1/2 or less than plate-graphite. When small, it may mean an active material which is located between the plate graphite particles and the surface of the particles to serve to space the surface and the surface. Specific examples are hard carbon, soft carbon, granulated artificial graphite, amorphous particle form If the well-known anode active material, such as artificial graphite, MCMB (mesocarbon microbead), spherical natural graphite, Li 4 Ti 5 O 12 is possible.
상술한 바와 같이, 판상 흑연을 입자상의 전극 활물질로 사용하는 경우에도 가압 성형에 의해 판상 흑연들이 패킹(packing)됨으로써, 입자 단위에서 배향성을 갖는 성형체가 제조될 수 있다. 이때, 판상 흑연과 함께 탄소 전구체를 사용(복합 입자의 형태나 활물질과 별도인 첨가제의 형태)함으로써, 성형 강도를 향상시킬 수 있음은 물론이다.As described above, even when the plate graphite is used as the particulate electrode active material, the plate graphite is packed by pressure molding, whereby a molded article having an orientation in the particle unit can be produced. At this time, of course, by using a carbon precursor together with plate-like graphite (in the form of composite particles or in the form of an additive separate from the active material), the molding strength can be improved.
열처리에 의해 탄소계 전구체를 탄소로 전환(열분해)시켜 활물질 벌크의 전기전도도를 향상시킬 수 있으며, 필요시, 선택적으로, 흑연화 열처리를 더 수행하여 음극 활물질로 전환시킬 수도 있음은 물론이다. 열분해는 탄소계 전구체의 구체 물질을 고려하여 종래 알려진 조건에서 수행하면 무방하며, 흑연화 처리 또한 탄소를 흑연화하는데 사용되는 종래 알려진 조건에서 수행하면 무방하다. 일 예로, 열분해는 600 내지 1500℃의 온도로 수행될 수 있으며, 흑연화는 2800 ℃ 이상의 온도로 수행될 수 있으나, 이러한 범위로 한정될 수 없음은 물론이다.The heat treatment may convert the carbon-based precursor into carbon (pyrolysis) to improve the electrical conductivity of the bulk of the active material, and optionally, further convert the negative electrode active material by selectively performing a graphitization heat treatment. The pyrolysis may be carried out under conventionally known conditions in consideration of the specific material of the carbon-based precursor, and the graphitization treatment may also be performed under the conventionally known conditions used for graphitizing carbon. For example, pyrolysis may be performed at a temperature of 600 to 1500 ° C., and graphitization may be performed at a temperature of 2800 ° C. or more, but is not limited thereto.
즉, 일 구체예에 따른 제조방법은 활물질 및 탄소 전구체를 함유하는 원료, 또는 활물질, 탄소 전구체 및 도전재를 함유하는 원료를 성형하여 성형체를 제조하는 단계; 성형체를 열처리하여 소결체를 제조하는 단계;를 포함할 수 있다. 이때, 소결을 위한 열처리시 탄소 전구체의 열분해가 동시에 발생할 수 있다. 필요시 보다 완전한 열분해를 위해 소결체를 열처리하여 탄소계 전구체가 탄소로 열분해된 2차 소결체를 제조하는 단계;가 더 수행될 수 있다. 또한, 필요시 열분해 탄소를 흑연화하기 위해, 소결체 또는 2차 소결체를 열처리하여 열분해 탄소가 흑연화된 소결체를 제조하는 단계;가 더 수행될 수 있다. That is, the manufacturing method according to one embodiment comprises the steps of molding a raw material containing the active material and the carbon precursor, or a raw material containing the active material, the carbon precursor and the conductive material to produce a molded article; And heat-treating the molded body to produce a sintered body. At this time, thermal decomposition of the carbon precursor may occur simultaneously during the heat treatment for sintering. If necessary, to heat the sintered body for more complete pyrolysis to prepare a secondary sintered body in which the carbon-based precursor is pyrolyzed into carbon; may be further performed. In addition, in order to graphitize the pyrolytic carbon when necessary, the step of heat-treating the sintered body or the secondary sintered body to produce a sintered body graphitized pyrolytic carbon; may be further performed.
본 발명의 일 구체예에 있어, 성형체 또는 소결체인 활물질 벌크의 겉보기 기공률은 10 내지 45%일 수 있으며, 구체적으로 15 내지 40%일 수 있다. 또한, 활물질 막의 겉보기 기공률은 10 내지 45%일 수 있으며, 구체적으로 15 내지 40%일 수 있다. 활물질 막이 활물질 벌크를 절단하여 제조됨에 따라, 활물질 막은 활물질 벌크와 실질적으로 동일한 기공률을 가질 수 있다. In one embodiment of the present invention, the apparent porosity of the bulk of the active material is a molded or sintered body may be 10 to 45%, specifically, may be 15 to 40%. In addition, the apparent porosity of the active material film may be 10 to 45%, specifically 15 to 40%. As the active material film is prepared by cutting the bulk of the active material, the active material film may have substantially the same porosity as the bulk of the active material.
원료에 함유되는 첨가제의 종류나 함량등에 따라 활물질 벌크(및 활물질 막)의 조성이 달라질 수 있다. 원료가 도전재를 함유하는 경우, 즉, 활물질 막이 도전재를 함유하는 경우, 활물질 막은 전극 활물질 100 중량부 기준 1 내지 30중량부, 구체예로 1 내지 20중량부의 도전재를 함유할 수 있으나, 반드시 이에 제한되는 것은 아니다.The composition of the bulk of the active material (and the active material film) may vary depending on the type or content of the additive contained in the raw material. When the raw material contains the conductive material, that is, when the active material film contains the conductive material, the active material film may contain 1 to 30 parts by weight, specifically 1 to 20 parts by weight of the conductive material, based on 100 parts by weight of the electrode active material. It is not necessarily limited thereto.
원료의 유기 바인더나 탄소 전구체에 의해, 활물질 막이 열분해 탄소를 함유하는 경우, 활물질 막은 전극 활물질 100 중량부 기준 0.5 내지 30 중량부의 열분해 탄소, 구체예로, 1 내지 25 중량부의 열분해 탄소를 함유할 수 있으나, 반드시 이에 제한되는 것은 아니다.When the active material film contains pyrolyzed carbon by the organic binder or carbon precursor of the raw material, the active material film may contain 0.5 to 30 parts by weight of pyrolyzed carbon, specifically, 1 to 25 parts by weight of pyrolyzed carbon based on 100 parts by weight of the electrode active material. However, it is not necessarily limited thereto.
성형체 또는 소결체로 활물질 벌크를 제조한 후, 면취나 직육면체등의 목적하는 치수로 가공하기 위해 활물질 벌크를 절삭 및/또는 연삭 가공하는 가공 단계가 더 수행될 수 있음은 물론이다.After the bulk of the active material is manufactured from the molded body or the sintered body, a processing step of cutting and / or grinding the active material bulk may be further performed in order to process to a desired dimension such as chamfering or rectangular parallelepiped.
제조된 활물질 벌크의 절단은 와이어 쏘우(wire saw), 레이저 커팅등, 종래 반도체 웨이퍼 제조를 위해 사용되는 반도체 잉곳(ingot)을 절단하는데 통상적으로 사용되는 방법을 사용하여 수행될 수 있으며, 본 발명이 활물질 벌크의 구체적 절단 방법에 의해 한정되는 것은 아니다.Cutting of the prepared active material bulk may be performed using a method commonly used to cut semiconductor ingots used for conventional semiconductor wafer manufacture, such as wire saws, laser cutting, and the like. It is not limited by the specific cutting method of an active material bulk.
활물질 벌크를 절단하되, 절단 폭을 조절하여 활물질 막의 두께를 용이 조절할 수 있으며, 단일한 활물질 벌크를 반복적으로 절단함으로써 실질적으로 동일한 품질의 활물질 막을 대량 생산할 수 있다. 활물질 벌크의 절단 폭에 의해 활물질 막의 두께가 제어됨에 따라, 제조되는 활물질 막의 두께에 제약이 없으며, 슬러리 도포 기술에 의해서는 제조되기 어려운, 두께가 200μm이상인 후막 형태의 활물질 막 또한 용이 제조 가능하다. 그러나, 본 발명이 활물질 막의 두께에 의해 한정될 수 없음은 물론이며, 활물질 막의 두께는 활물질 이차전지의 용도에 따라 적절히 조절될 수 있음은 물론이다. 구체예로, 활물질 막의 두께는 수십 마이크로미터 오더(order)에서 수 미리미터 오더(order)에 이를 수 있으며, 보다 구체적으로 10μm 내지 500μm일 수 있으나, 이에 한정되는 것은 아니다.By cutting the active material bulk, it is possible to easily control the thickness of the active material film by adjusting the cutting width, it is possible to mass-produce an active material film of substantially the same quality by repeatedly cutting a single active material bulk. As the thickness of the active material film is controlled by the cutting width of the bulk of the active material, there is no limitation in the thickness of the active material film to be produced, and an active material film in the form of a thick film having a thickness of 200 μm or more, which is difficult to be produced by slurry coating technology, can also be easily manufactured. However, the present invention is not limited by the thickness of the active material film, of course, the thickness of the active material film can be appropriately adjusted according to the use of the active material secondary battery. In an embodiment, the thickness of the active material film may range from several tens of micrometers order to several millimeters order, more specifically, 10 μm to 500 μm, but is not limited thereto.
도 4는 성형체인 활물질 벌크를 절단하여 제조된 활물질 막(300)의 단면을 도시한 도면이며, 도 5는 소결체인 활물질 벌크를 절단하여 제조된 활물질 막(300)의 단면을 도시한 도면이다. 도 4 및 도 5에서 명확한 이해를 위해, 활물질 막(또는 활물질 벌크)이 전극 활물질로 이루어진 경우를 도시하였으나, 상술한 바와 같이, 활물질 벌크는 도전재, 탄소계 전구체 및/또는 바인더등과 같은 첨가제를 더 포함할 수 있음은 물론이다.4 is a cross-sectional view of an active material film 300 prepared by cutting an active material bulk that is a molded body, and FIG. 5 is a cross-sectional view of an active material film 300 prepared by cutting an active material bulk that is a sintered body. For the sake of clarity in FIG. 4 and FIG. 5, the case where the active material film (or the bulk of the active material) is made of the electrode active material is illustrated. As described above, the active material bulk is an additive such as a conductive material, a carbon-based precursor and / or a binder, and the like. Of course, it may further include.
도 4 및 도 5에 도시한 일 예와 같이, 활물질 막(300)이 활물질 벌크(200)로부터 절단된 절단막인 제조방법적 구성에 의해, 활물질 막의 표면에 위치하는 활물질은 잘린 입자상일 수 있다. 이때, 잘린 입자상의 잘린 면은 활물질 막(300)의 표면과 평행할 수 있다. 달리 상술하면, 활물질 막(300)의 표면은 잘린 입자상의 잘린 면들을 포함할 수 있다. As shown in FIGS. 4 and 5, due to the manufacturing method configuration in which the active material film 300 is a cut film cut from the active material bulk 200, the active material located on the surface of the active material film may be cut particulates. . In this case, the cut surface of the cut particles may be parallel to the surface of the active material film 300. In detail, the surface of the active material film 300 may include the cut surfaces of the cut particles.
이때, 도 4와 같이 활물질 벌크가 성형체인 경우 잘린 입자상은 활물질 벌크의 내부 중심에 위치하는 전극 활물질 입자(내부 입자)의 형상이 기준이 되어, 임의의 일 평면을 따라 내부 입자가 잘려진 형상을 의미할 수 있다. In this case, as shown in FIG. 4, when the bulk of the active material is a molded body, the cut particulates refer to a shape of the electrode active material particles (inner particles) positioned at an inner center of the active material bulk, and the inner particles are cut along an arbitrary plane. can do.
또한, 도 5와 같이 활물질 벌크가 소결체인 경우, 잘린 입자상은 활물질 벌크의 내부 중심에 위치하여 서로 결착된 상태의 전극 활물질 입자(내부 입자)의 형상이 기준이 되어, 임의의 일 평면을 따라 내부 입자가 잘려진 형상을 의미할 수 있다. 상술한 바 및 도 5에 도시한 일 예와 같이, 활물질 벌크가 소결체인 경우, 활물질 벌크는 원료로 함유되는 전극 활물질 입자(110)간 넥이 형성된 소결 초기의 소결체인 것이 유리하다. 이에 따라, 활물질 벌크가 소결체인 경우, 원료로 함유되는 전극 활물질 입자(110)의 형상을 기준으로 임의의 일 평면을 따라 원료로 함유되는 전극 활물질 입자(110)가 잘려진 형상을 의미할 수 있다. 원료로 함유되는 전극 활물질 입자 기준 잘려진 형상에서, 잘린 입자가 엄밀하게 원료로 함유되는 전극 활물질 입자(110)의 잘려진 입자 형태로 해석되어서는 안 된다. 소결체 제조를 위한 열처리시 치밀화나 입자성장에 의해 물질 이동이 이루어지며 입자간 접촉점에 오목한 곡률 영역이 생성되는 것임에 따라, 이러한 오목한 곡률 영역인 넥 영역이 잘려진 형상에서 적절히 고려될 수 있음은 물론이다. In addition, when the bulk of the active material is a sintered body as shown in FIG. 5, the cut particulates are located at the inner center of the bulk of the active material, and the shape of the electrode active material particles (inner particles) in the state of being bound to each other is used as a reference, and the inside of the cut particles is formed along an arbitrary plane. It may mean a shape in which the particles are cut off. As described above and as an example illustrated in FIG. 5, when the active material bulk is a sintered body, it is advantageous that the active material bulk is a sintered body at the initial stage of sintering in which a neck between electrode active material particles 110 contained as a raw material is formed. Accordingly, when the bulk of the active material is a sintered body, it may mean a shape in which the electrode active material particles 110 contained in the raw material are cut along an arbitrary plane based on the shape of the electrode active material particles 110 contained in the raw material. In the cut-out shape based on the electrode active material particles contained as a raw material, the cut particles should not be interpreted strictly as cut particles of the electrode active material particles 110 contained as raw materials. As the material movement is performed by densification or particle growth during heat treatment for producing a sintered body, and concave curvature regions are generated at contact points between particles, the concave curvature neck region may be properly considered in the cut shape. .
본 발명의 일 실시예에 따른 제조방법은, 활물질 벌크를 절단하여 활물질 막을 제조한 후 및 일체화 전, 또는 활물질 막과 집전체를 일체화한 후, 활물질 막의 적어도 일 표면을 표면 처리하는 단계를 더 포함할 수 있다. 이러한 표면 처리는 표면 거칠기 조절을 포함할 수 있다. 구체적으로, 표면 처리 단계는 활물질 막의 적어도 일 표면의 표면 거칠기를 상대적(처리전 활물질 막의 표면 대비)으로 감소시키는 처리이거나, 활물질 막의 적어도 일 표면의 표면 거칠기를 상대적으로 증가시키는 처리일 수 있으며, 활물질 막의 일 표면의 표면 거칠기는 감소시키며 다른 일 표면의 표면 거칠기는 증가시키는 처리일 수 있다.The manufacturing method according to an embodiment of the present invention further includes the step of surface treatment of at least one surface of the active material film after cutting the bulk of the active material to prepare the active material film and before integration or after the active material film and the current collector are integrated. can do. Such surface treatment may include surface roughness control. Specifically, the surface treatment step may be a treatment of reducing the surface roughness of at least one surface of the active material film relative to the surface of the active material film before treatment, or a process of relatively increasing the surface roughness of at least one surface of the active material film, The surface roughness of one surface of the film may be reduced and the surface roughness of the other surface may be increased.
표면 거칠기를 상대적으로 감소시키는 처리의 일 예로 표면 연마(polishing)을 들 수 있으며, 표면 거칠기를 상대적으로 증가시키는 처리의 일 예로, 표면 에칭, 기계적 스크래치(scratch)등을 들 수 있다. 이때, 표면 에칭은 플라즈마 에칭, 활물질 막이 탄소계 전극 활물질을 포함하는 경우 표면 영역의 부분 산화등을 들 수 있으나, 본 발명이 이에 한정되는 것은 아니며, 무기막이나 탄소계 막의 표면 거칠기를 증가 또는 감소시키기 위해 통상적으로 사용되는 어떠한 표면 처리 방법을 사용하여도 무방하다.An example of a treatment for reducing surface roughness may be surface polishing, and one example of a treatment for increasing surface roughness may include surface etching, mechanical scratch, and the like. In this case, the surface etching may include plasma etching, partial oxidation of the surface area when the active material film includes a carbon-based electrode active material, but the present invention is not limited thereto. The surface roughness of the inorganic film or the carbon-based film may be increased or decreased. Any surface treatment method conventionally used for the purpose may be used.
활물질 벌크로부터 활물질 막을 제조한 후, 집전체와 활물질 막을 일체화하는 단계(결착 단계)가 수행될 수 있다. 이때, 일체화는 집전체와 활물질 막이 직접적으로 결착된 상태, 또는 집전체와 활물질 막이 서로 부착된 상태를 의미할 수 있다. After preparing the active material film from the bulk of the active material, a step (binding step) of integrating the current collector and the active material film may be performed. In this case, integration may mean a state in which the current collector and the active material film are directly bound, or a state in which the current collector and the active material film are attached to each other.
결착 단계의 일 예로, 활물질 막 상에 직접 금속 막이 형성되어 일체화가 이루어질 수 있다. 활물질 막이 활물질 벌크에서 절단된 막인 구성, 구체적으로, 프리-스탠딩 가능한 막인 구성에 의해, 활물질 막은 기재(기판)로 작용할 수 있다. 이에, 활물질 막을 기재로, 활물질 막의 일 면에 금속 막을 형성함으로써 집전체와 활물질 막간의 일체화가 수행될 수 있다. 금속 막의 형성은 금속의 증착(화학적, 물리적 증착을 포함함)이나, 전도성 잉크의 도포 및 열처리등과 같이 종래 전극이나 금속 막을 형성하기 위해 통상적으로 사용하는 방법이면 무방하다.As an example of the binding step, a metal film may be directly formed on the active material film, thereby integrating the same. By the configuration in which the active material film is a film cut out of the active material bulk, specifically, the structure in which the film is free-standable, the active material film can act as a substrate (substrate). Thus, by forming a metal film on one surface of the active material film based on the active material film, integration between the current collector and the active material film can be performed. Formation of the metal film may be any method conventionally used to form a conventional electrode or metal film, such as metal deposition (including chemical and physical vapor deposition), conductive ink application, and heat treatment.
결착 단계의 다른 일 예로, 결착 단계는 c1) 집전체의 표면과 상기 활물질 막의 표면 중 적어도 일 표면에 접착층을 형성하는 단계; 및 c2) 상기 접착층을 사이에 두고 집전체와 상기 활물질 막이 맞닿도록 적층하는 단계;를 포함할 수 있다.As another example of the binding step, the binding step may include: c1) forming an adhesive layer on at least one of the surface of the current collector and the surface of the active material film; And c2) laminating the current collector and the active material film to be in contact with each other with the adhesive layer therebetween.
접착층은 집전체의 일 표면, 활물질 막의 일 표면 또는 집전체의 일 표면과 활물질 막의 일 표면 각각에 형성될 수 있다. 접착층의 형성은 접착제가 유동상인 경우 집전체의 표면과 활물질 막의 표면 중 적어도 일 표면에 접착제를 도포하여 형성될 수 있다. 접착제의 도포는 액상이나 분산상의 도포에 통상적으로 사용되는 도포 방법으로 수행되면 무방하며, 일 예로, 딥코팅, 스핀 코팅, 캐스팅, 바-코팅, 그라비아-코팅, 블레이드 코팅 및 롤-코팅, 스프레이, 스크린 프린팅, 잉크젯 프린팅, 정전수력학 프린팅, 마이크로 컨택 프린팅, 임프린팅, 그라비아 프린팅, 옵셋-리버스옵셋 프린팅등에서 하나 이상 선택되는 도포 방법으로 수행될 수 있으며 코팅은 면코팅, 선코팅, 점코팅 등의 형태로 수행될 수 있으나 이에 한정되는 것은 아니다. 접착제가 독립된 필름 형태인 경우 집전체의 표면과 활물질 막의 표면 중 적어도 일 표면에 접착제 필름을 부착하여 형성될 수 있다. 이때, 접착제의 도포량은 0.1 내지 1mg/cm 2 수준일 수 있으나, 이에 한정되는 것은 아니다. The adhesive layer may be formed on one surface of the current collector, one surface of the active material film, or one surface of the current collector and one surface of the active material film. The adhesive layer may be formed by applying an adhesive to at least one of the surface of the current collector and the surface of the active material film when the adhesive is a fluid phase. The application of the adhesive may be carried out by an application method commonly used for the application of liquid or dispersion phases. For example, dip coating, spin coating, casting, bar coating, gravure coating, blade coating and roll coating, spray, Screen printing, inkjet printing, electrostatic printing, micro-contact printing, imprinting, gravure printing, offset-reverse offset printing, etc. can be performed by one or more application methods selected.The coating may be performed by surface coating, line coating, point coating, etc. It may be performed in the form, but is not limited thereto. When the adhesive is in the form of an independent film, the adhesive may be formed by attaching an adhesive film to at least one of the surface of the current collector and the surface of the active material film. At this time, the coating amount of the adhesive may be 0.1 to 1mg / cm 2 level, but is not limited thereto.
집전체의 표면과 활물질 막의 표면 중 적어도 일 표면에 접착층을 형성한 후, 접착층을 사이에 두고 집전체와 상기 활물질 막이 맞닿도록 적층하여 활물질 막을 집전체에 부착시킬 수 있다. 균일한 접착, 접착제의 경화, 결착력의 강화나 신속한 결착등을 위해, 집전체와 활물질막의 적층시, 열, 광 및 압력 중 하나 이상이 인가될 수 있다. 실질적인 일 예로, 집전체와 활물질막의 적층시, 열이 인가될 수 있으며, 열과 함께 압력이 인가될 수 있다. 접착시 열과 압력이 인가되는 일 구체예로, 열간 압착등을 들 수 있으며, 열간 압착시 압력은 면압방식 및 선압 방식의 프레싱 등에의해 인가될 수 있으나, 본 발명이 이에 한정되는 것은 아니다.After forming an adhesive layer on at least one of the surface of the current collector and the surface of the active material film, the active material film may be attached to the current collector by laminating the current collector and the active material film in contact with each other with the adhesive layer therebetween. At least one of heat, light, and pressure may be applied when laminating the current collector and the active material film for uniform adhesion, curing of the adhesive, strengthening of the binding force, or rapid binding. As a practical example, when laminating the current collector and the active material film, heat may be applied and pressure may be applied together with the heat. As an example of applying heat and pressure during adhesion, hot pressing and the like may be used, and the pressure during hot pressing may be applied by pressing in a surface pressure method or a linear pressure method, but the present invention is not limited thereto.
결착 단계에서 집전체의 적어도 일면, 즉, 집전체의 일면 또는 집전체의 두 대향면 각각에 활물질 막이 결착될 수 있다. In the binding step, the active material film may be bound to at least one surface of the current collector, that is, one surface of the current collector or each of two opposite surfaces of the current collector.
집전체의 서로 대향하는 두 면 각각에 활물질 막을 부착하고자 하는 경우, 집전체의 서로 대향하는 두 표면 중 일 표면에 c1) 내지 c2) 단계를 통해 활물질 막을 부착한 후, 두 대향면 중 다른 일 표면에 다시 c1) 내지 c2) 단계를 통해 활물질 막을 부착하며, 집전체의 서로 대향하는 두 면 각각에 활물질 막을 부착할 수 있다.When the active material film is to be attached to each of two opposite surfaces of the current collector, the active material film is attached to one of two opposite surfaces of the current collector through steps c1) to c2), and then the other one of the two opposite surfaces. The active material film may be attached to the active material film again through steps c1) to c2, and the active material film may be attached to each of two opposite surfaces of the current collector.
이와 달리, c1) 단계에서 접착층을 사이에 두고 집전체의 두 대향면 각각이 활물질 막과 맞닿을 수 있도록 접착층을 형성하고, c2) 단계에서 집전체를 중심으로 접착층과 활물질 막이 샌드위치 구조를 이루도록 적층함으로써, 집전체의 서로 대향하는 두 면 각각에 활물질 막을 부착할 수 있다.In contrast, in step c1), an adhesive layer is formed such that each of two opposing surfaces of the current collector contacts the active material film with the adhesive layer interposed therebetween, and in step c2), the adhesive layer and the active material film are stacked to form a sandwich structure around the current collector. Thus, the active material film can be attached to each of two opposite surfaces of the current collector.
앞서 상술한 바와 같이, 전극의 활물질 막은 프리-스탠딩 가능한 막일 수 있으며, 도 4와 같이, 성형체로부터 절단된 절단막이거나, 도 5와 같이 소결체로부터 절단된 절단막일 수 있다. As described above, the active material film of the electrode may be a free-standing film, and may be a cut film cut from a molded body as shown in FIG. 4, or a cut film cut from a sintered body as shown in FIG. 5.
도 6은 전극의 단면을 도시한 일 단면도로, 접착층(400)에 의해, 집전체(500)의 두 대향면 각각에 전극 활물질(210)과 전도성 입자(220)를 함유하는 활물질 막(300)이 부착된 예를 도시한 도면이다. 도 6의 활물질 막(300)은 소성 변형 가능한 입자상의 전극 활물질이 가압 성형에 의해 눌린 입자 형태로 소성 변형되며 전극 활물질 입자들의 배향성이 형성되거나, 플레이크 형태의 전극 활물질이 가압 성형되며 일 방향으로 패킹(packing)됨으로써 전극 활물질 입자들의 배향성(입자 단위의 배향성)이 형성된 성형체로부터 절단된 절단막을 도시한 예이다. 또한, 도 6의 활물질 막(300)은 활물질 벌크를, 활물질 벌크 내 전극 활물질의 배향 방향에 수직으로 절단면이 형성되도록 절단하여, 활물질 막의 두께 방향과 막내 활물질의 배향 방향(활물질 입자 단위의 배향 방향)이 실질적으로 평행한 예를 도시한 도면이다.FIG. 6 is a cross-sectional view illustrating a cross section of an electrode, and includes an electrode active material 210 and conductive particles 220 on two opposite surfaces of the current collector 500 by an adhesive layer 400. It is a figure which shows the attached example. The active material film 300 of FIG. 6 may be plastically deformed into a particle form in which the electrode active material which is plastically deformable is pressed by press molding and the orientation of the electrode active material particles are formed, or the electrode active material of the flake shape is press molded and packed in one direction. It is an example which shows the cut film cut | disconnected from the molded object in which the orientation (the orientation of a particle unit) of the electrode active material particle was formed by packing. In addition, the active material film 300 of FIG. 6 cuts the active material bulk so that a cut surface is formed perpendicularly to the alignment direction of the electrode active material in the active material bulk, and the thickness direction of the active material film and the orientation direction of the active material in the film (orientation direction in units of active material particles). Is a view showing an example in which substantially parallel.
도 6에 도시한 바와 같이, 활물질 막(300)의 두께 방향과 전극 활물질의 배향 방향(활물질 입자 단위의 배향 방향)이 실질적으로 평행한 경우, 입자와 입자간의 틈이 열린 기공을 형성하며, 활물질 막의 표면에서 집전체 측과의 계면으로 막을 가로지르는 유체 이동 경로를 형성하여, 실질적으로 막의 두께와 무관하게 안정적이며 균일하게 전해액(및 리튬 이온)이 침투할 수 있다.As shown in FIG. 6, when the thickness direction of the active material film 300 and the orientation direction (the orientation direction of the active material particle unit) of the electrode active material are substantially parallel, pores between the particles and the particles are opened to form pores. By forming a fluid migration path across the membrane from the surface of the membrane to the interface with the current collector side, electrolyte (and lithium ions) can penetrate stably and uniformly substantially independently of the thickness of the membrane.
또한, 도 5와 같이, 활물질 막이 전극 활물질 입자간 넥이 형성된 막, 즉, 초기 소결단계의 소결체로부터 절단된 절단막인 경우에도, 마찬가지로, 입자와 입자 사이의 연속된 틈에 의해, 열린 표면 기공과 활물질 막의 두께를 가로지르는 기공 채널이 균일하게 형성되어, 실질적으로 막의 두께와 무관하게 안정적이며 균일하게 전해액(및 리튬 이온)이 침투할 수 있다.In addition, as shown in FIG. 5, even when the active material film is a film in which a neck between electrode active material particles is formed, that is, a cut film cut from the sintered body of the initial sintering step, the surface pores opened by the continuous gap between the particles and the particles are similarly opened. And the pore channel across the thickness of the active material film is uniformly formed so that the electrolyte solution (and lithium ions) can penetrate stably and uniformly regardless of the thickness of the film.
접착층(400)은 경화능을 갖는 수지를 포함할 수 있다. 이때, 경화능을 갖는다 함은 화학적 변화, 건조(용매의 휘발 제거) 또는 고화에 의해 유동성을 잃고 굳어질 수 있는 능력을 의미한다. The adhesive layer 400 may include a resin having curability. At this time, having curability means the ability to lose fluidity and harden by chemical change, drying (volatile removal of solvent) or solidification.
상세하게, 경화능을 갖는 수지의 경화능은 액상(용융상)에서 고상으로의 상변태(고화)에 의한 경화, 용매의 휘발 제거에 따른 경화 및/또는 화학적 변화에 의한 경화를 포함할 수 있다. 이에 따라, 경화능을 갖는 수지는 용매에 용해된 상태의 수지(수지 용액), 열 가소성 수지(용융-응고에 의해 고화능을 갖는 수지), 광 경화성 수지, 열 경화성 수지 및 화학 경화성 수지에서 하나 또는 둘 이상 선택되는 수지등을 들 수 있다. In detail, the hardenability of the resin having a hardenability may include hardening by phase transformation (solidification) from a liquid phase (melted phase) to hard phase, hardening due to volatilization of the solvent, and / or hardening by chemical change. Accordingly, the resin having a curing ability is one of a resin (resin solution), a thermoplastic resin (resin having a solidification ability by melting-solidification), a photocurable resin, a thermosetting resin, and a chemical curable resin in a state dissolved in a solvent. Or two or more selected resins.
열가소성 수지는 열에 인가시 용융(내지 연화)가 발생하는 알려진 어떠한 수지도 사용가능하다. 일 예로, 열 가소성 수지는 폴리아미드 수지, 폴리에스테르 수지(예를 들어 폴리에틸렌테레프탈레이트 등의 방향족 폴리에스테르 수지 등), 폴리아세탈 수지, 폴리카르보네이트 수지, 폴리페닐렌에테르 수지, 폴리술피드 수지, 폴리술폰 수지, 폴리에테르케톤 수지, 폴리올레핀 수지, 폴리스티렌 수지 등을 포함할 수 있으나, 이에 한정되는 것은 아니다. 열가소성 수지는 단독 또는 2종 이상 조합하여 사용 가능하다. The thermoplastic resin may be used in any known resin in which melting (or softening) occurs upon application to heat. For example, the thermoplastic resin may be a polyamide resin, a polyester resin (eg, an aromatic polyester resin such as polyethylene terephthalate), a polyacetal resin, a polycarbonate resin, a polyphenylene ether resin, or a polysulfide resin. , Polysulfone resin, polyether ketone resin, polyolefin resin, polystyrene resin and the like, but is not limited thereto. The thermoplastic resins may be used alone or in combination of two or more thereof.
접착층이 열가소성 수지를 포함하는 경우, 접착층을 사이에 두고 집전체와 활물질 막이 맞닿도록 적층된 적층체에 열을 인가하여 열가소성 수지의 용융(또는 연화) 및 냉각에 의해 활물질 막이 집전체에 결착될 수 있다. 이때, 결착력을 향상시키고 균일한 결착이 이루어지도록 열과 함께 압력이 인가될 수 있음은 물론이다.When the adhesive layer includes a thermoplastic resin, the active material film may be bound to the current collector by melting (or softening) and cooling the thermoplastic resin by applying heat to a laminate laminated so that the current collector and the active material film are in contact with the adhesive layer therebetween. have. At this time, the pressure may be applied together with the heat to improve the binding force and to achieve a uniform binding.
접착층이 수지 용액을 포함하는 경우, 수지 용액의 도포막을 사이에 두고 집전체와 활물질 막이 맞닿도록 적층된 적층하고, 수지 용액의 용매를 휘발 제거함으로써 활물질 막이 집전체에 결착될 수 있다. 수지 용액의 사용시 수지 용액에 용해된 수지는 앞서 첨가제의 일 예로 상술한 바인더 물질(수계 바인더 및/ 또는 비수계 바인더)을 포함할 수 있다. When the adhesive layer contains a resin solution, the active material film may be bound to the current collector by laminating the current collector and the active material film so as to be in contact with each other with a coating film of the resin solution therebetween, and volatilizing removing the solvent of the resin solution. The resin dissolved in the resin solution when using the resin solution may include the above-described binder material (aqueous binder and / or non-aqueous binder) as an example of the additive.
상술한 바와 같이, 접착층은 열 경화성, 광 경화성 및/또는 화학적 경화성의 경화성 수지를 포함할 수 있다. 이때, 집전체나 활물질층의 광 투과율이 낮은 경우, 접착층은 열 경화성 수지 및/또는 화학적 경화성 수지를 함유하는 것 좋다.As described above, the adhesive layer may comprise a thermosetting, photocurable and / or chemically curable resin. At this time, when the light transmittance of the current collector or the active material layer is low, the adhesive layer may contain a thermosetting resin and / or a chemical curable resin.
열 경화성 수지 또는 화학적 경화성 수지는 열 또는 화학적으로 경화되는 것으로 알려진 어떠한 수지이든 무방하며, 일 예로, 에폭시 수지, 불포화 폴리에스테르 수지, 비닐에스테르 수지, 아크릴 수지, 페놀 수지, 요소 수지, 멜라민 수지, 아닐린 수지, 폴리이미드 수지, 비스말레이미드 수지 등을 들 수 있으나, 이에 한정되는 것은 아니다. 경화성 수지는 단독으로 또는 2종 이상 조합하여도 무방하다. 접착층이 열 경화성 수지 또는 화학적 경화성 수지를 함유하는 경우, 해당 수지에 사용하는 것으로 알려진 경화제나 경화 촉진제를 더 함유할 수 있음은 물론이다.The thermosetting resin or the chemical curable resin may be any resin known to be thermally or chemically cured, and examples thereof include epoxy resins, unsaturated polyester resins, vinyl ester resins, acrylic resins, phenol resins, urea resins, melamine resins, aniline Resins, polyimide resins, bismaleimide resins, and the like, but are not limited thereto. Curable resin may be used individually or in combination of 2 or more types. When the adhesive layer contains a thermosetting resin or a chemical curable resin, it is of course possible to further contain a curing agent or a curing accelerator known to be used for the resin.
접착층은 전도성 또는 비전도성일 수 있다. The adhesive layer can be conductive or nonconductive.
접착층이 비 전도성인 경우, 접착층은 상술한 경화능을 갖는 비 전도성 수지를 포함할 수 있다. When the adhesive layer is non-conductive, the adhesive layer may include a non-conductive resin having the above-described hardenability.
접착층이 전도성인 경우, 접착층은 전도성 수지, 전도성 입자 및 전도성 나노구조체에서 하나 이상 선택되는 전도성 성분을 포함할 수 있다. 이러한 전도성 성분은 수지 용액이나 수지 용융액등에 혼합되어 수지와 함께 도포될 수 있다. When the adhesive layer is conductive, the adhesive layer may include a conductive component selected from one or more of conductive resins, conductive particles, and conductive nanostructures. Such a conductive component may be mixed with a resin solution or a resin melt and applied together with the resin.
구체 예로, 접착층이 전도성인 경우, 접착층은 상술한 경화능을 갖는 비 전도성 수지와 함께, 전도성 입자 및 전도성 나노구조체에서 하나 이상 선택되는 성분을 포함할 수 있다. In an embodiment, when the adhesive layer is conductive, the adhesive layer may include one or more components selected from conductive particles and conductive nanostructures, together with the non-conductive resin having the above-described hardenability.
구체 예로, 접착층이 전도성인 경우, 접착층은 전도성 수지를 포함할 수 있다. 전도성 수지는 적어도 용매의 휘발 제거에 따른 경화능(즉, 건조에 의한 경화)을 가질 수 있으나, 이에 한정되는 것은 아니며, 작용기에 의해 열이나 화학 경화능을 갖거나 응고(용융-응고의 상변태)에 의한 경화능을 가질 수도 있음은 물론이다.In an embodiment, when the adhesive layer is conductive, the adhesive layer may include a conductive resin. The conductive resin may have at least a curing ability (ie, curing by drying) according to the volatilization of the solvent, but is not limited thereto, and may have heat or chemical curing ability or solidify (phase transformation of melt-solidification) by a functional group. Of course, it may have a curing ability by.
구체 예로, 접착층이 전도성인 경우, 접착층은 전도성 수지와 함께, 전도성 입자 및 전도성 나노구조체에서 하나 이상 선택되는 성분을 포함할 수 있다. In an embodiment, when the adhesive layer is conductive, the adhesive layer may include, together with the conductive resin, one or more components selected from conductive particles and conductive nanostructures.
즉, 접착층은 수지 매트릭스를 포함할 수 있으며, 수지 매트릭스가 경화능을 갖는 전도성 수지인 전도성 접착층일 수 있다. 또는 접착층은 수지 매트릭스를 포함할 수 있으며, 수지매트릭스가 비전도성 수지이되, 수지 매트릭스에 분산되어 위치하며 전도성 입자 및 전도성 나노구조체에서 하나 이상 선택되는 분산상을 포함하는 전도성 접착층일 수 있다.That is, the adhesive layer may include a resin matrix, and the resin matrix may be a conductive adhesive layer which is a conductive resin having curability. Alternatively, the adhesive layer may include a resin matrix, and the resin matrix may be a non-conductive resin, and may be a conductive adhesive layer including a dispersed phase selected from the conductive particles and the conductive nanostructures, which are disposed in the resin matrix.
접착층의 전도성 입자는 전도성 수지 입자, 금속의 입자, 비전도성 코어-전도성 쉘(전도성 수지의 쉘 또는 금속 쉘)의 코어쉘 입자 및 전도성 코어-비전도성 쉘의 코어쉘 입자에서 하나 또는 둘 이상 선택되는 입자를 포함할 수 있으나, 이에 한정되는 것은 아니다.The conductive particles of the adhesive layer are one or more selected from conductive resin particles, particles of metal, coreshell particles of a nonconductive core-conductive shell (shell or metal shell of conductive resin) and coreshell particles of a conductive core-nonconductive shell. It may include particles, but is not limited thereto.
접착층의 전도성 나노구조체는 은 나노와이어와 같은 금속 나노와이어; 탄소나노튜브등과 같은 전도성 나노튜브; 금 나노판이나 은 나노판등과 같은 금속 나노판; 그래핀등과 같은 2차원 탄소체, 은 나노막대등과 같은 금속 나노막대; 또는 이들의 혼합물을 포함할 수 있으나, 이에 한정되는 것은 아니다.The conductive nanostructures of the adhesive layer may be metal nanowires such as silver nanowires; Conductive nanotubes such as carbon nanotubes; Metal nanoplates such as gold nanoplates and silver nanoplates; Two-dimensional carbon bodies such as graphene, metal nanorods such as silver nanorods, etc .; Or a mixture thereof, but is not limited thereto.
접착층의 전도성 수지는 폴리아세틸렌(Polyacetylene), 폴리피롤(polypyrrole), PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)), 폴라아닐린( polyanilne), P3MT(poly(3-methylthiophene)), 또는 이들의 혼합 수지등일 수 있으나, 이에 한정되는 것은 아니다.The conductive resin of the adhesive layer is polyacetylene, polypyrrole, PEDOT: PSS (poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate)), polyanilne, P3MT (poly (3-methylthiophene)), Or a mixed resin thereof, but is not limited thereto.
또한, 전도성 또는 비전도성 접착층은 종래 전자 부품의 플립칩 접속이나 칩 실장등의 패키징 분야에서 접착을 위해 사용되는 통상의 비전도성 필름(NCF; non-contuctive film), 이방전도성 필름(ACF; Anisotropic Conductive Film), 전도성 필름(CF; contuctive film) 또는 이들의 적층막;이거나, 이방 전도성 페이스트(ACP; Anisotropic Conductive Paste), 전도성 페이스트(Conductive Paste) 또는 비전도성 페이스트(NCP; Non-Conductive Paste)의 도포막;일 수 있으나, 이에 한정되는 것은 아니다. In addition, the conductive or non-conductive adhesive layer is a conventional non-conductive film (NCF; non-contuctive film), anisotropic conductive film (ACF) used for bonding in packaging fields, such as flip chip connection or chip mounting of conventional electronic components Film), a conductive film (CF) or a laminated film thereof; or an anisotropic conductive paste (ACP), a conductive paste (Conductive Paste) or a non-conductive paste (NCP) Membrane; but is not limited thereto.
집전체(500)는 이차전지 분야에서 통상적으로 사용되며 전지 작동시 화학적 변화를 유발하지 않으면서 높은 도전성을 가지는 물질이면 사용 가능하다. 구체적인 일 예로, 집전체는 구리, 스테인레스 스틸, 알루미늄, 니켈, 티타늄, 소성 탄소, 그래핀, 탄소나노튜브, 또는 알루미늄이나 스테인레스 스틸의 표면에 카본, 니켈, 티타늄, 은, 그래핀, 탄소나노튜브 등으로 표면 처리한 것 등이 사용될 수 있다. 집전체는 폼(foam), 박(film), 메쉬(mesh), 펠트(felt) 또는 다공성 박(perforated film) 형태일 수 있다. 또한, 집전체는 그 표면에 표면 요철이 형성된 것일 수 있다. 돌출 구조를 포함하는 표면 요철이 형성된 집전체의 경우, 결착 면적이 증가하며 활물질 막과 집전체 간의 결착력을 증가시킬 수 있으며, 전하전달이 보다 용이하게 발생할 수 있다. The current collector 500 is commonly used in the secondary battery field and may be used as long as it has a material having high conductivity without causing chemical change during battery operation. As a specific example, the current collector may be copper, stainless steel, aluminum, nickel, titanium, calcined carbon, graphene, carbon nanotube, or carbon, nickel, titanium, silver, graphene, carbon nanotube on the surface of aluminum or stainless steel. And the like may be used as surface treated. The current collector may be in the form of a foam, film, mesh, felt or porous film. In addition, the current collector may have a surface irregularities formed on its surface. In the case of the current collector having the surface irregularities including the protruding structure, the binding area may increase, and the binding force between the active material film and the current collector may be increased, and charge transfer may occur more easily.
본 발명은 상술한 제조방법으로 제조된 이차전지용 전극을 포함한다. 이때, 이차전지는 전해액 기반 이차전지, 구체적으로, 양극; 음극; 및 양극과 음극 사이에 개재된 분리막; 및 전해액을 포함하는 이차전지일 수 있다. 또한, 이차전지는 리튬 이차전지를 포함한다.The present invention includes an electrode for secondary batteries manufactured by the above-described manufacturing method. At this time, the secondary battery is an electrolyte-based secondary battery, specifically, a positive electrode; cathode; And a separator interposed between the anode and the cathode; And it may be a secondary battery containing an electrolyte. In addition, the secondary battery includes a lithium secondary battery.
본 발명은 상술한 제조방법으로 제조된 이차전지용 전극을 포함하는 리튬 이차전지를 포함한다. 이차전지에서 상술한 제조방법으로 제조된 이차전지용 전극은 양극, 음극 또는 양극과 음극일 수 있다.The present invention includes a lithium secondary battery including the secondary battery electrode manufactured by the above-described manufacturing method. The secondary battery electrode manufactured by the above-described manufacturing method in the secondary battery may be a positive electrode, a negative electrode or a positive electrode and a negative electrode.
이와 함께, 또는 이와 독립적으로, 본 발명은 이차전지용 전극을 제공한다.In addition, or independently of the present invention, the present invention provides an electrode for a secondary battery.
본 발명에 따른 이차전지용 전극은 전극 활물질을 함유하는 활물질 막, 집전체 및 활물질 막을 집전체에 부착시키는 접착제를 포함할 수 있다. 상세하게, 전극은 집전체-접착제 층(접착층)-활물질 막의 구조를 가질 수 있으며, 활물질 막이 접착제 층(접착층)에 의해 집전체의 일 면 또는 집전체 양면에 각각에 결착된 전극일 수 있다. The secondary battery electrode according to the present invention may include an active material film containing an electrode active material, a current collector and an adhesive for attaching the active material film to the current collector. In detail, the electrode may have a structure of a current collector-adhesive layer (adhesive layer) -active material film, and the active material film may be an electrode bound to each side of the current collector or both sides of the current collector by an adhesive layer (adhesive layer).
본 발명에 따른 이차전지용 전극은 전극 활물질을 함유하는 활물질 막을 포함하며, 활물질 막은 유기 바인더를 함유하지 않는 바인더-프리(binder-free) 막일 수 있다.The secondary battery electrode according to the present invention includes an active material film containing an electrode active material, and the active material film may be a binder-free film containing no organic binder.
본 발명에 따른 이차전지용 전극은 전극 활물질을 함유하는 활물질 막을 포함하며, 활물질 막은 프리 스탠딩 가능한 막일 수 있다.The secondary battery electrode according to the present invention includes an active material film containing an electrode active material, the active material film may be a free standing film.
이때, 이차전지는 전해액 기반 이차전지, 구체적으로, 양극; 음극; 및 양극과 음극 사이에 개재된 분리막; 및 전해액을 포함하는 이차전지일 수 있으며, 이차전지는 리튬 이차전지를 포함한다.At this time, the secondary battery is an electrolyte-based secondary battery, specifically, a positive electrode; cathode; And a separator interposed between the anode and the cathode; And it may be a secondary battery including an electrolyte, the secondary battery includes a lithium secondary battery.
전극 활물질 슬러리를 이용하여 활물질층을 제조하는 종래 기술의 경우, 전극 활물질 슬러리를 도포 및 건조한 후 압연이 수행됨에 따라 활물질층 표면과 내부의 기공률이 달라질 뿐만 아니라, 활물질층 표면에서 기공이 막힐 위험이 있다. 그러나, 본 발명은, 활물질 막이 활물질 벌크를 절단하여 제조됨에 따라, 활물질 막은 막의 두께 방향으로 균일한 기공률을 가질 수 있으며, 활물질 막은 두께 방향에서의 위치와 무관하게 실질적으로 동일한 기공률과 기공 구조를 가질 수 있다. In the prior art of manufacturing an active material layer by using an electrode active material slurry, as the electrode active material slurry is coated and dried, rolling is performed, as well as the porosity of the surface and the inside of the active material layer is changed, and there is a risk of pore clogging at the surface of the active material layer. have. However, in the present invention, as the active material film is prepared by cutting the bulk of the active material, the active material film may have a uniform porosity in the thickness direction of the film, and the active material film has substantially the same porosity and pore structure regardless of the position in the thickness direction. Can be.
상세하게, 활물질 막의 단면을 기준으로 표면 영역과 막의 중앙영역간 실질적으로 동일한 기공률을 가질 수 있다. 균일한 기공률은 활물질 막의 단면을 기준으로, 표면 영역에서의 기공률(P1)과 중앙 영역에서의 기공률(P2)의 차(P1-P2의 절대값)를 중앙 영역에서의 기공률로 나눈 비율이 10% 이하, 실질적으로 8% 이하, 보다 실질적으로 5%이하일 수 있으며, 일 예로, 실질적으로 동일할 수 있다. 이때, 실질적으로 동일하다 함은 측정 오차 이내에서 동일함을 의미한다. 실험적으로, 활물질 막 단면의 기공률은 활물질 막의 중심을 가로지르는 두께 단면에서, 두께 단면의 단위 면적 당 기공이 차지하는 면적일 수 있다. 이때, 표면 영역은 활물질 막의 두께(t 0)를 기준으로, 표면에서 0.2t 0까지의 영역을 의미할 수있으며, 중앙 영역은 두께 단면의 중심(중심 선, 0.5t 0의 가상 선)을 기준으로 상부 및 하부 각각으로 0.1t 0까지의 영역(0.4t 0~0.6t 0의 영역)을 의미할 수 있다. 또한, 표면 영역의 기공률은 서로 대향하는 두 표면 중 임의의 일 표면 에서뿐만 아니라, 두 표면 각각에서의 기공률을 의미할 수 있다. 실험적으로, 두께 단면에 기준한 기공률은 주사전자현미경등의 단면 관찰 이미지를 이용하여 산출될 수 있다. In detail, the porosity may be substantially the same between the surface area and the central area of the film based on the cross section of the active material film. The uniform porosity is based on the cross section of the active material film, and the ratio of the difference between the porosity (P1) in the surface region and the porosity (P2) in the center region (the absolute value of P1-P2) divided by the porosity in the center region is 10%. Or less, substantially less than or equal to 8%, more substantially less than or equal to 5%, for example, substantially the same. At this time, substantially identical means identical within a measurement error. Experimentally, the porosity of the cross section of the active material film may be an area occupied by pores per unit area of the cross section of the thickness in the thickness cross section across the center of the active material film. In this case, the surface area may mean an area up to 0.2t 0 from the surface based on the thickness (t 0 ) of the active material film, and the center area is based on the center (center line, virtual line of 0.5t 0 ) of the thickness cross section. This may mean an area up to 0.1t 0 (an area of 0.4t 0 to 0.6t 0 ) as the upper and lower portions, respectively. Also, the porosity of the surface region may refer to the porosity at each of the two surfaces as well as at any one of the two surfaces facing each other. Experimentally, the porosity based on the thickness cross section can be calculated using a cross-sectional observation image such as a scanning electron microscope.
본 발명의 일 실시예에 따른 이차전지용 전극에 있어, 전극 활물질, 활물질 막 또는 집전체는 이차전지용 전극의 제조방법에서 상술한 바와 유사 내지 동일하며, 접착제는 이차전지용 전극의 제조방법에서 상술한 접착층의 물질과 유사 내지 동일하다. 이에 따라, 본 발명에 따른 이차전지용 전극은 앞서 상술한 이차전지용 전극의 제조방법에 기재된 모든 내용을 포함한다.In the secondary battery electrode according to an embodiment of the present invention, the electrode active material, the active material film or the current collector is similar to or the same as described above in the method of manufacturing a secondary battery electrode, the adhesive is the adhesive layer described in the method of manufacturing a secondary battery electrode Similar to the material of. Accordingly, the secondary battery electrode according to the present invention includes all the contents described in the above-described method for producing a secondary battery electrode.
본 발명은 상술한 이차전지용 전극을 포함하는 이차전지, 구체적으로 리튬 이차전지를 포함한다.The present invention includes a secondary battery, specifically, a lithium secondary battery including the secondary battery electrode.
이와 함께, 또는 이와 독립적으로, 본 발명은 리튬 이차전지를 포함한다.In addition or independently of this, the present invention includes a lithium secondary battery.
본 발명에 따른 리튬 이차전지는 양극; 음극; 및 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함하며, 양극 및 음극에서 하나 이상 선택되는 전극은 접착제에 의해 집전체의 적어도 일 면에 전극 활물질을 함유하는 활물질 막이 부착된 것일 수 있다. Lithium secondary battery according to the present invention is a positive electrode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the electrode selected from at least one of the positive electrode and the negative electrode may include an active material film containing an electrode active material attached to at least one surface of the current collector by an adhesive.
양극 및 음극에서 하나 이상 선택되는 전극이 양극인 경우, 양극은 양극 활물질을 함유하는 활물질 막이 접착제에 의해 집전체의 적어도 일 면에 부착된 것일 수 있다. 즉, 본 발명의 일 실시예에 따른 리튬 이차전지는 양극 활물질을 함유하는 활물질 막이 접착제에 의해 집전체의 적어도 일 면에 부착된 양극; 음극; 및 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함할 수 있다. 이때, 음극은 집전체상 위치하는 음극활물질층을 포함할 수 있으며, 음극활물질층의 음극활물질은 리튬 이차전지의 음극에 통상적으로 사용되는 물질이면 무방하며, 음극활물질은 리튬 인터칼레이션 가능한 물질이면 족하다. 비 한정적인 일 예로, 음극활물질은 리튬(금속 리튬), 이흑연화성 탄소, 난흑연화성 탄소, 그라파이트, 실리콘, Sn 합금, Si 합금, Sn 산화물, Si 산화물, Ti 산화물, Ni 산화물, Fe 산화물(FeO) 및 리튬-티타늄 산화물(LiTiO 2, Li 4Ti 5O 12)등에서 하나 또는 둘 이상 선택된 물질일 수 있다.When at least one electrode selected from the positive electrode and the negative electrode is a positive electrode, the positive electrode may be an active material film containing a positive electrode active material attached to at least one surface of the current collector by an adhesive. That is, a lithium secondary battery according to an embodiment of the present invention includes a positive electrode having an active material film containing a positive electrode active material attached to at least one surface of the current collector by an adhesive; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution. In this case, the negative electrode may include a negative electrode active material layer positioned on the current collector, the negative electrode active material of the negative electrode active material layer may be a material commonly used for the negative electrode of a lithium secondary battery, and the negative electrode active material may be a lithium intercalable material. It is enough. As a non-limiting example, the negative electrode active material is lithium (metal lithium), digraphitizable carbon, non-graphitizable carbon, graphite, silicon, Sn alloy, Si alloy, Sn oxide, Si oxide, Ti oxide, Ni oxide, Fe oxide ( FeO) and lithium-titanium oxide (LiTiO 2 , Li 4 Ti 5 O 12 ) and the like may be one or more selected materials.
양극 및 음극에서 하나 이상 선택되는 전극이 음극인 경우, 음극은 음극 활물질을 함유하는 활물질 막이 접착제에 의해 집전체의 적어도 일 면에 부착된 것일 수 있다. 즉, 본 발명의 일 실시예에 따른 리튬 이차전지는 양극; 음극 활물질을 함유하는 활물질 막이 접착제에 의해 집전체의 적어도 일 면에 부착된 음극; 및 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함할 수 있다. 이때, 양극은 집전체상 위치하는 양극활물질층을 포함할 수 있으며, 양극활물질층의 양극활물질은 리튬 이온의 가역적인 탈/삽입이 가능한 물질이면 사용 가능하며, 통상적인 리튬 이차전지의 양극에 사용되는 전극 물질이면 무방하다. 일 예로, 양극활물질은 LiCoO 2로 대표되는 층상 구조의 산화물, LiMn 2O 4로 대표되는 스피넬 구조의 산화물 또는 LiFePO 4로 대표되는 올리빈 구조의 포스페이트계 물질등일 수 있다. When at least one electrode selected from the positive electrode and the negative electrode is a negative electrode, the negative electrode may be an active material film containing a negative electrode active material attached to at least one surface of the current collector by an adhesive. That is, a lithium secondary battery according to an embodiment of the present invention is a positive electrode; An anode in which an active material film containing an anode active material is attached to at least one surface of the current collector by an adhesive; And a separator interposed between the anode and the cathode; And an electrolyte solution. In this case, the positive electrode may include a positive electrode active material layer positioned on the current collector, and the positive electrode active material of the positive electrode active material layer may be used as long as it is a material capable of reversible insertion / removal of lithium ions, and used for a positive electrode of a conventional lithium secondary battery. Any electrode material may be used. For example, the cathode active material may be an oxide having a layer structure represented by LiCoO 2 , an oxide having a spinel structure represented by LiMn 2 O 4 , or a phosphate material having an olivine structure represented by LiFePO 4 .
양극 및 음극에서 하나 이상 선택되는 전극이 양극과 음극인 경우, 본 발명의 일 실시예에 따른 리튬 이차전지는 양극 활물질을 함유하는 활물질 막이 접착제에 의해 집전체의 적어도 일 면에 부착된 양극; 음극 활물질을 함유하는 활물질 막이 접착제에 의해 집전체의 적어도 일 면에 부착된 음극; 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함할 수 있다.When at least one electrode selected from the positive electrode and the negative electrode is a positive electrode and a negative electrode, a lithium secondary battery according to an embodiment of the present invention is a positive electrode having an active material film containing a positive electrode active material attached to at least one surface of the current collector by an adhesive; An anode in which an active material film containing an anode active material is attached to at least one surface of the current collector by an adhesive; A separator interposed between the positive electrode and the negative electrode; And an electrolyte solution.
본 발명의 일 실시예에 따른 리튬 이차전지에 있어, 전극 활물질, 활물질 막 또는 집전체는 이차전지용 전극의 제조방법에서 상술한 바와 유사 내지 동일하며, 접착제는 이차전지용 전극의 제조방법에서 상술한 접착층의 물질과 유사 내지 동일하다. 이에 따라, 본 발명에 따른 리튬 이차전지는 앞서 상술한 이차전지용 전극의 제조방법에 기재된 모든 내용을 포함한다.In the lithium secondary battery according to an embodiment of the present invention, the electrode active material, the active material film or the current collector is similar to or the same as described above in the method of manufacturing a secondary battery electrode, and the adhesive is the adhesive layer described in the method of manufacturing a secondary battery electrode. Similar to the material of. Accordingly, the lithium secondary battery according to the present invention includes all the contents described in the above-described method for manufacturing the electrode for secondary batteries.
분리막은 통상의 리튬 이차전지에서 리튬 이온이 투과되며 양극과 음극을 전기적으로 절연시키는 미세 다공막이면 무방하다. 구체예로, 분리막은 다공성 고분자 필름, 예컨대 에틸렌 단독 중합체, 프로필렌 단독중합체, 에틸렌/부텐 공중합체, 이텔린/헥센 공중합체 및 에틸렌/메타크릴레이트 공중합체 등과 같은 폴리올레핀계 고분자로 제조한 다공성 고분자 필름 단독 또는 이들의 적층체일 수 있으며, 또는 통상적인 다공성 부직포, 예를 들어 고융점의 유리 섬유, 폴리에틸렌테레프탈레이트 섬유 등으로 된 부직포를 사용할 수 있으나, 이에 제한되는 것은 아니다.The separator may be a microporous membrane in which lithium ions are permeable in a conventional lithium secondary battery and electrically insulate the positive electrode and the negative electrode. In one embodiment, the separator is a porous polymer film, such as a porous polymer film made of a polyolefin-based polymer such as ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ytterin / hexene copolymer and ethylene / methacrylate copolymer, etc. It may be a single or a laminate thereof, or a conventional porous nonwoven fabric, for example, a non-woven fabric of high melting glass fibers, polyethylene terephthalate fibers and the like can be used, but is not limited thereto.
분리막은 통상의 리튬이차전지와 같이 단순히 양극과 음극사이에 위치시켜 양극과 음극을 분리시키는 역할을 할 수 있다. 또한, 분리막은 양극과 음극 중 적어도 하나 이상의 전극에 결착(부착)된 상태일 수 있다. The separator may serve to separate the positive electrode and the negative electrode by simply positioned between the positive electrode and the negative electrode as in a conventional lithium secondary battery. In addition, the separator may be in a state of being bound (attached) to at least one electrode of the positive electrode and the negative electrode.
전해질은 통상의 리튬 이차전지에서, 전지의 충전 및 방전에 관여하는 이온을 원활히 전도시키는 통상의 비수계 전해질이면 족하다. 일 예로, 비수계 전해질은 비수계 용매 및 리튬염을 포함할 수 있다. 비 한정적인 일 예로, 전해질에 함유되는 리튬염은 리튬 양이온 및 NO 3 -, N(CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2PF 4 -, (CF 3) 3PF 3 -, (CF 3) 4PF 2 -, (CF 3) 5PF -, (CF 3) 6P -, CF 3SO 3 -, CF 3CF 2SO 3 -, (CF 3SO 2) 2N -, (FSO 2) 2N -, CF 3CF 2(CF 3) 2CO -, (CF 3SO 2) 2CH -, (SF 5) 3C -, (CF 3SO 2) 3C -, CF 3(CF 2) 7SO 3 -, CF 3CO 2 -, CH 3CO 2 -, SCN -, 및 (CF 3CF 2SO 2) 2N -에서 하나 이상 선택되는 음이온을 제공하는 염일 수 있다. The electrolyte may be any conventional non-aqueous electrolyte that smoothly conducts ions involved in charging and discharging the battery in a conventional lithium secondary battery. For example, the non-aqueous electrolyte may include a non-aqueous solvent and a lithium salt. An example non-limiting one, the lithium salt contained in the electrolyte is a lithium cation and NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2 PF 4 -, (CF 3) 3 PF 3 -, ( CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, CF 3 CF 2 SO 3 -, (CF 3 SO 2) 2 N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, (CF 3 SO 2) 3 C -, CF 3 (CF 2) 7 SO 3 -, CF 3 CO 2 -, CH 3 CO 2 -, SCN -, and (CF 3 CF 2 SO 2) 2 N - providing an anion selected at least one from It may be a salt.
전해질의 용매는 에틸렌 카보네이트(ethylene carbonate), 프로필렌 카보네이트, 1,2-부틸렌 카보네이트, 2,3-부틸렌 카보네이트, 1,2-펜틸렌 카보네이트, 2,3-펜틸렌 카보네이트, 비닐렌 카보네이트, 디메틸 카보네이트, 디에틸 카보네이트, 디(2,2,2-트리플루오로에틸) 카보네이트, 디프로필 카보네이트, 디부틸 카보네이트, 에틸메틸 카보네이트, 2,2,2-트리플루오로에틸 메틸 카보네이트, 메틸프로필 카보네이트, 에틸프로필카보네이트, 2,2,2-트리플루오로에틸 프로필 카보네이트, 메틸 포르메이트(methyl formate), 에틸 포르메이트, 프로필 포르메이트, 부틸 포르메이트, 디메틸 에테르(dimethyl ether), 디에틸 에테르, 디프로필 에테르, 메틸에틸 에테르, 메틸프로필 에테르, 에틸프로필 에테르, 메틸 아세테이트(methyl acetate), 에틸 아세테이트, 프로필 아세테이트, 부틸 아세테이트, 메틸 프로피오네이트, 에틸 프로피오네이트(ethyl propionate), 프로필 프로피오네이트, 부틸 프로피오네이트, 메틸 부티레이트(methyl butyrate), 에틸 부티레이트, 프로필 부티레이트, 부틸 부티레이트, γ-부티로락톤(γ-butyrolactone), 2-메틸-γ-부티로락톤, 3-메틸-γ-부티로락톤, 4-메틸-γ-부티로락톤, γ-티오부티로락톤, γ-에틸-γ-부티로락톤, β-메틸-γ-부티로락톤, γ-발레로락톤(γ-valerolactone), σ-발레로락톤, γ-카프로락톤(γ-caprolactone), ε-카프로락톤, β-프로피오락톤(β-propiolactone), 테트라하이드로퓨란 (tetrahydrofuran), 2-메틸 테트라하이드로퓨란, 3-메틸테트라하이드로퓨란, 트리메틸 포스페이트(trimethyl phosphate), 트리에틸 포스페이트, 트리스(2-클로로에틸) 포스페이트, 트리스(2,2,2-트리플루오로에틸) 포스페이트, 트리프로필 포스페이트, 트리이소프로필 포스페이트, 트리부틸 포스페이트, 트리헥실 포스페이트, 트리페닐 포스페이트, 트리톨릴 포스페이트, 메틸 에틸렌 포스페이트, 에틸 에틸렌 포스페이트, 디메틸 설폰(dimethyl sulfone), 에틸 메틸 설폰, 메틸 트리플루오로메틸 설폰, 에틸 트리플루오로메틸 설폰, 메틸 펜타플루오로에틸 설폰, 에틸 펜타플루오로에틸 설폰, 디(트리플루오로메틸)설폰, 디(펜타플루오로에틸) 설폰, 트리플루오로메틸 펜타플루오로에틸 설폰, 트리플루오로메틸 노나플루오로부틸 설폰, 펜타플루오로에틸 노나플루오로부틸 설폰, 술포란(sulfolane), 3-메틸술포란, 2-메틸술포란, 3-에틸술포란 및 2-에틸술포란등에서 하나 이상 선택된 용매를 들 수 있다. 그러나, 본 발명이 상술한 리튬염 및 용매에 의해 한정될 수 없음은 물론이다.The solvent of the electrolyte is ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, vinylene carbonate, Dimethyl carbonate, diethyl carbonate, di (2,2,2-trifluoroethyl) carbonate, dipropyl carbonate, dibutyl carbonate, ethylmethyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, methylpropyl carbonate , Ethylpropyl carbonate, 2,2,2-trifluoroethyl propyl carbonate, methyl formate, ethyl formate, propyl formate, butyl formate, dimethyl ether, diethyl ether, di Propyl ether, methylethyl ether, methylpropyl ether, ethylpropyl ether, methyl acetate, ethyl acetate, propyl acetate, butyl butyl Tate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, γ-butyrolactone (γ- butyrolactone), 2-methyl-γ-butyrolactone, 3-methyl-γ-butyrolactone, 4-methyl-γ-butyrolactone, γ-thiobutyrolactone, γ-ethyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone, γ-valerolactone, γ-caprolactone, ε-caprolactone, β-propiolactone (β- propiolactone, tetrahydrofuran, 2-methyl tetrahydrofuran, 3-methyltetrahydrofuran, trimethyl phosphate, triethyl phosphate, tris (2-chloroethyl) phosphate, tris (2,2, 2-trifluoroethyl) phosphate, tripropyl phosphate, triisopropyl Phosphate, tributyl phosphate, trihexyl phosphate, triphenyl phosphate, tritolyl phosphate, methyl ethylene phosphate, ethyl ethylene phosphate, dimethyl sulfone, ethyl methyl sulfone, methyl trifluoromethyl sulfone, ethyl trifluoromethyl sulfone , Methyl pentafluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoromethyl) sulfone, di (pentafluoroethyl) sulfone, trifluoromethyl pentafluoroethyl sulfone, trifluoromethyl nonafluoro One or more solvents selected from butyl sulfone, pentafluoroethyl nonafluorobutyl sulfone, sulfolane, 3-methyl sulfolane, 2-methyl sulfolane, 3-ethyl sulfolane and 2-ethyl sulfolane have. However, it is a matter of course that the present invention cannot be limited by the above-described lithium salt and solvent.
본 발명의 일 실시예에 따른 리튬 이차전지는 양극과 음극 사이에 개재된 분리막을 포함하는 전극 조립체를 제조하고, 제조된 전극 조립체를 케이스에 장입한 후, 전해질을 주입하고 밀봉하여 제조할 수 있다. 또는, 전해질에 함침된 전극 조립체를 케이스에 장입 및 밀봉하여 제조할 수도 있다. 전지 케이스는 리튬 이차전지 분야에서 통상적으로 사용되는 것이면 무방하다. 일 예로, 원통형, 각형, 파우치형 또는 코인형 등을 들 수 있으나, 본 발명이 전지 케이스의 구체 형상에 의해 제한될 수 없음은 물론이다.According to an embodiment of the present invention, a lithium secondary battery may be manufactured by manufacturing an electrode assembly including a separator interposed between a positive electrode and a negative electrode, inserting the prepared electrode assembly into a case, and injecting and sealing an electrolyte. . Alternatively, the electrode assembly impregnated in the electrolyte may be prepared by charging and sealing the case. The battery case may be one commonly used in the lithium secondary battery field. As an example, a cylindrical, square, pouch or coin type may be mentioned, but the present invention may not be limited by the spherical shape of the battery case.
본 발명은 상술한 이차전지, 일 예로, 리튬 이차전지를 단위 전지셀로, 단위 전지셀이 직렬 및/또는 병렬 연결된 전지모듈을 포함한다.The present invention includes the above-described secondary battery, for example, a lithium secondary battery as a unit battery cell, and a battery module in which unit battery cells are connected in series and / or in parallel.
본 발명은 상술한 이차전지, 일 예로, 리튬 이차전지에 의해 전력이 공급되는 장치를 포함한다. 구체 예로, 장치는 전기자동차, 하이브리드 전기자동차, 플러그-인 하이브리드 전기자동차, 전력 저장용 시스템 등을 들 수 있으나, 이에 한정되는 것은 아니다.The present invention includes a device that is powered by the above-described secondary battery, for example, a lithium secondary battery. Specific examples include, but are not limited to, electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, power storage systems, and the like.
도 7은 본 발명의 일 실시예에 따라 제조된 활물질 막(3cmx5cmx280μm) 을 관찰한 광학 사진이다. 도 7의 활물질 막은 성형 및 소결에 의해 활물질 벌크를 제조한 후, 전동 소(saw)를 이용하여 280μm 두께로 절삭한 것이다. 상세하게, 성형은 인조흑연:피치가 8:2의 중량비로 혼합된 혼합물을 성형 몰드에 넣고 압축하여 1차 성형한 후, 1차 성형된 성형체를 CIP(cold isostatic pressing)으로 2차 가압하여 수행되었다. 소결은 산소농도 50ppm이하의 질소 분위기에서 제조된 성형체를 2℃/min 속도로 700℃까지 승온하고 700℃에서 60분간 1차 열처리하고, 다시 700℃에서 1200℃까지 3℃/min 속도로 승온하여 1200℃에서 60분간 2차 열처리하여 활물질 벌크를 제조하였다. 제조된 활물질 벌크 및 활물질 막의 겉보기 기공률은 실질적으로 동일하였으며, 19.8%였다.7 is an optical picture of observing an active material film (3cmx5cmx280μm) prepared according to an embodiment of the present invention. The active material film of FIG. 7 is manufactured by bulking an active material by molding and sintering, and then cut to a thickness of 280 μm using an electric saw. In detail, molding is performed by putting a mixture of artificial graphite: pitch mixed at a weight ratio of 8: 2 into a molding mold and compressing the first molding, and then pressing the first molded article by cold isostatic pressing (CIP) secondarily. It became. Sintering was carried out in a nitrogen-molded atmosphere of less than 50ppm oxygen temperature to 700 ℃ at 2 ℃ / min speed, the first heat treatment at 700 ℃ 60 minutes, and then again at 700 ℃ to 1200 ℃ 3 ℃ / min rate Bulk active material was prepared by secondary heat treatment at 1200 ° C. for 60 minutes. The apparent porosity of the prepared active material bulk and the active material film was substantially the same, and was 19.8%.
도 8(a)는 제조된 활물질 막의 표면을 관찰한 주사전자현미경 사진이며, 도 8(b)는 제조된 활물질 막의 두께 단면을 관찰한 주사전자현미경 사진이다. 도 8에서 알 수 있듯이, 이미 균일한 특성을 갖는 활물질 벌크를 절단하여 활물질 막이 제조됨에 따라, 활물질 막의 표면 및 두께 단면에서 실질적으로 동일한 기공률을 가지며, 활물질 막이 열린 기공 구조를 가짐을 알 수 있다. 또한, 제조된 활물질 막의 두께 단면에서 표면 영역과 중앙 영역을 관찰하여 기공 면적을 측정한 결과 실질적으로 동일한 기공률을 가짐을 확인하였다. FIG. 8 (a) is a scanning electron microscope photograph of the surface of the prepared active material film, and FIG. 8 (b) is a scanning electron microscope photograph of a thickness cross section of the prepared active material film. As can be seen in Figure 8, as the active material film is prepared by cutting the bulk of the active material having already uniform properties, it can be seen that the active material film has an open pore structure having substantially the same porosity in the surface and thickness cross-section of the active material film. In addition, when the pore area was measured by observing the surface area and the center area in the thickness cross section of the prepared active material film, it was confirmed that they had substantially the same porosity.
도 9는 도 7 및 도 8의 활물질 막을 집전체인 Cu 포일(foil)에 부착시킨 음극을 관찰한 광학 사진이다. 도 8의 음극 제조시, 활물질 막을 폴리싱(polishing)하여 경면화를 수행한 후 경면화된 면을 집전체에 부착하였으며, 전도성 접착제로 구리 페이스트(30nm 구리 나노입자 65중량%, 스티렌-부타디엔 고무 8중량%)를 사용하였다. FIG. 9 is an optical photograph of a cathode obtained by attaching the active material films of FIGS. 7 and 8 to a Cu foil as a current collector. In preparing the negative electrode of FIG. 8, after the active material film was polished to perform mirror hardening, the mirrored surface was attached to the current collector, and a copper paste (65 wt% of 30 nm copper nanoparticles and styrene-butadiene rubber 8) was used as a conductive adhesive. Weight percent)).
표 1은 도 8의 음극을 사용하여 제조된 이차전지의 특성을 정리 도시한 것이다. 표 1에서 비교예(1 및 2)는 흑연을 활물질로 하고, 유기 바인더/활물질 중량 비율(%)이 3.1인 조건으로, 음극 슬러리의 도포, 건조 및 압연의 종래 슬러리 방법을 이용하여 제조된 음극이 구비된 이차전지의 결과로, 활물질층의 두께를 서로 달리하여 제조된 예이다. Table 1 summarizes the characteristics of the secondary battery manufactured using the negative electrode of FIG. 8. In Table 1, Comparative Examples (1 and 2) were prepared using a conventional slurry method of coating, drying, and rolling a negative electrode slurry, using graphite as an active material and an organic binder / active material weight ratio (%) of 3.1. As a result of the secondary battery provided, it is an example produced by varying the thickness of the active material layer.
전극 제조시, 양극으로 리튬 메탈(3.2cmx5.2cmx2mm)을 사용하였으며, 음극과 양극 극판사이에 분리막(폴리에틸렌, 두께 25㎛)를 개재하여 전지를 구성하고, 양극의 탭부분과 음극의 탭부분을 각각 용접을 하였다.When manufacturing the electrode, lithium metal (3.2cmx5.2cmx2mm) was used as the positive electrode, and the battery was formed between the negative electrode and the positive electrode plate through a separator (polyethylene, 25 μm thick), and the tab portion of the positive electrode and the tab portion of the negative electrode were Each was welded.
용접된 양극/분리막/음극의 조합체를 파우치 안에 넣고, 탭이 있는 부분은 실링 부위에 포함시켜 전해액 주액부 면을 제외한 3면을 실링하였다. 나머지 한 부분으로 전해액을 주액하고 남은 한 면을 실링한 후, 12시간 이상 함침시켰다. 전해액으로 에틸렌카보네이트(EC) / 에틸메틸카보네이트(EMC) / 디에틸렌카보네이트(DEC) (25/45/30; 부피비)의 혼합 용매로 1M LiPF 6 용액을 사용하였다.The welded anode / separator / cathode combination was placed in a pouch, and the tabbed portion was included in the sealing portion to seal three surfaces except the electrolyte injection surface. After pouring the electrolyte into the remaining part and sealing the remaining side, it was impregnated for 12 hours or more. 1M LiPF 6 solution was used as a mixed solvent of ethylene carbonate (EC) / ethyl methyl carbonate (EMC) / diethylene carbonate (DEC) (25/45/30; volume ratio) as the electrolyte.
이후, 0.05C에 해당하는 전류(13mA, 0.9mA/cm 2)로 약 20시간 충전을 실시하였다. 충전이 완료된 후 0.1C로 1.5V까지 방전을 하여 용량 및 충방전 효율을 측정하였다. (충전조건 CC/CV 0.05C 0.05V 0.01C CUT-OFF, 방전조건 CC 0.1C 1.5V CUT-OFF).Then, charging was performed for about 20 hours at a current (13 mA, 0.9 mA / cm 2 ) corresponding to 0.05C. After the charging was completed, the battery was discharged to 0.1V at 0.1 C to measure capacity and charge and discharge efficiency. (Charge condition CC / CV 0.05C 0.05V 0.01C CUT-OFF, Discharge condition CC 0.1C 1.5V CUT-OFF).
(표 1)Table 1
Figure PCTKR2019003006-appb-img-000002
Figure PCTKR2019003006-appb-img-000002
표 1에서 알 수 있듯이, 종래 활물질 슬러리를 이용하여 활물질층을 제조하는 경우, 로딩량이 증가할수록 유기 바인더등에 의해 저항이 증가하며 용량이 감소함을 알 수 있으며, 특히 고율에서 큰 용량 감소가 발생함을 알 수 있다. 그러나, 본 발명의 일 실시예에 따라 제조된 전극의 경우, 막 전체적으로 균일한 열린 기공 구조가 유지되며 유기 바인더의 저항으로부터 자유로워, 280 μm의 후막에서도 용량과 효율 저하가 발생하지 않음을 알 수 있다.As can be seen from Table 1, when manufacturing the active material layer using a conventional active material slurry, it can be seen that as the loading amount increases, the resistance is increased and the capacity is decreased by the organic binder, etc., in particular, a large capacity decrease occurs at a high rate. It can be seen. However, in the case of the electrode manufactured according to the embodiment of the present invention, it is understood that the uniform open pore structure is maintained throughout the membrane and is free from the resistance of the organic binder, so that a capacity and efficiency decrease does not occur even at a thick film of 280 μm. have.
이상과 같이 본 발명에서는 특정된 사항들과 한정된 실시예 및 도면에 의해 설명되었으나 이는 본 발명의 보다 전반적인 이해를 돕기 위해서 제공된 것일 뿐, 본 발명은 상기의 실시예에 한정되는 것은 아니며, 본 발명이 속하는 분야에서 통상의 지식을 가진 자라면 이러한 기재로부터 다양한 수정 및 변형이 가능하다. In the present invention as described above has been described by specific embodiments and limited embodiments and drawings, but this is only provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments, the present invention Those skilled in the art can make various modifications and variations from this description.
따라서, 본 발명의 사상은 설명된 실시예에 국한되어 정해져서는 아니되며, 후술하는 특허청구범위뿐 아니라 이 특허청구범위와 균등하거나 등가적 변형이 있는 모든 것들은 본 발명 사상의 범주에 속한다고 할 것이다.Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things that are equivalent to or equivalent to the claims as well as the following claims will belong to the scope of the present invention. .

Claims (37)

  1. 활물질 벌크를 절단하여 활물질 막을 제조하는 절단단계; 및Cutting the active material bulk to prepare an active material film; And
    집전체와 상기 활물질 막을 일체화하는 결착단계;A binding step of integrating a current collector and the active material film;
    를 포함하는 이차전지용 전극의 제조방법.Method of manufacturing an electrode for a secondary battery comprising a.
  2. 제 1항에 있어서,The method of claim 1,
    상기 절단 전, 입자상의 전극 활물질을 포함하는 원료를 이용하여 활물질 벌크(bulk)를 제조하는 벌크제조단계;를 더 포함하는 이차전지용 전극의 제조방법.A bulk manufacturing step of manufacturing an active material bulk (bulk) using a raw material containing a particulate electrode active material before cutting, further comprising a secondary battery electrode.
  3. 제 1항에 있어서,The method of claim 1,
    상기 전극 활물질은 음극 활물질 또는 양극 활물질인 이차전지용 전극의 제조방법.The electrode active material is a method of manufacturing an electrode for a secondary battery which is a negative electrode active material or a positive electrode active material.
  4. 제 1항에 있어서,The method of claim 1,
    상기 활물질 벌크는 프리 스탠딩 가능한 이차전지용 전극의 제조방법.The active material bulk is a method of manufacturing a secondary electrode for free standing electrodes.
  5. 제 2항에 있어서,The method of claim 2,
    상기 벌크제조단계는 상기 원료를 압축 성형하여 성형체를 제조하는 성형 단계; 또는 상기 성형 단계와 성형 단계에서 제조된 성형체를 열처리하여 소결체를 제조하는 소결단계;를 포함하는 이차전지용 전극의 제조방법.The bulk manufacturing step is a molding step of producing a molded body by compression molding the raw material; Or a sintering step of manufacturing a sintered body by heat-treating the molded body prepared in the molding step and the molding step.
  6. 제 1항에 있어서,The method of claim 1,
    상기 원료는 바인더, 도전재, 탄소 전구체 및 기공 형성제에서 하나 이상 선택되는 첨가제를 더 포함하는 이차전지용 전극의 제조방법.The raw material is a method for manufacturing a secondary battery electrode further comprises an additive selected from at least one of a binder, a conductive material, a carbon precursor and a pore former.
  7. 제 6항에 있어서,The method of claim 6,
    상기 도전재는 전도성 탄소, 전도성 고분자 및 금속에서 하나 또는 둘 이상 선택된 물질의 입자, 섬유, 나노구조체 또는 이들의 혼합물을 포함하는 이차전지용 전극의 제조방법.The conductive material is a method of manufacturing an electrode for a secondary battery comprising a particle, a fiber, a nanostructure or a mixture of one or more materials selected from conductive carbon, a conductive polymer and a metal.
  8. 제 6항에 있어서,The method of claim 6,
    상기 탄소 전구체는 코크스, 피치, 열경화성 수지 및 열가소성 수지에서 하나 이상 선택되는 이차전지용 전극의 제조방법. The carbon precursor is at least one selected from coke, pitch, thermosetting resin and thermoplastic resin.
  9. 제 1항에 있어서,The method of claim 1,
    상기 입자상의 입자는 전극 활물질의 코어; 이종 물질의 쉘;의 코어-쉘 구조인 이차전지용 전극의 제조방법.The particulate particles may include a core of an electrode active material; A method of manufacturing an electrode for a secondary battery having a core-shell structure of a shell of a different material.
  10. 제 9항에 있어서,The method of claim 9,
    상기 이종 물질은 제2전극활물질, 제2전극활물질의 전구체, 전도성 물질, 바인더, 탄소 전구체 또는 이들의 혼합물을 포함하는 이차전지용 전극의 제조방법.The dissimilar material may include a second electrode active material, a precursor of the second electrode active material, a conductive material, a binder, a carbon precursor, or a mixture thereof.
  11. 제 1항에 있어서,The method of claim 1,
    상기 활물질 벌크의 기공률에 의해 상기 활물질 막의 기공률이 제어되는 이차전지용 전극의 제조방법. A method of manufacturing an electrode for secondary batteries in which the porosity of the active material membrane is controlled by the porosity of the bulk of the active material.
  12. 제 1항에 있어서,The method of claim 1,
    상기 활물질 벌크 내 전극 활물질은 배향성을 가지며, 상기 절단단계의 절단 방향에 의해 상기 활물질 막의 두께 방향을 기준한 활물질 막 내 전극 활물질의 배향 방향이 제어되는 이차전지용 전극의 제조방법. The electrode active material in the active material bulk has an orientation, and the direction of orientation of the electrode active material in the active material film based on the thickness direction of the active material film is controlled by the cutting direction of the cutting step.
  13. 제 1항에 있어서,The method of claim 1,
    상기 결착단계는 The binding step
    상기 집전체의 표면과 상기 활물질 막의 표면 중 적어도 일 표면에 접착층을 형성하는 단계; 및Forming an adhesive layer on at least one of a surface of the current collector and a surface of the active material film; And
    상기 접착층을 사이에 두고 상기 집전체와 상기 활물질 막이 맞닿도록 적층하는 단계;를 포함하는 이차전지용 전극의 제조방법. And stacking the current collector and the active material film to be in contact with each other with the adhesive layer therebetween. 2.
  14. 제 1항에 있어서,The method of claim 1,
    상기 결착단계는The binding step
    상기 활물질 막의 일 표면에 금속 막을 형성하는 단계;를 포함하는 이차전지용 전극의 제조방법.Forming a metal film on one surface of the active material film; manufacturing method of a secondary battery electrode comprising a.
  15. 제 3항에 있어서,The method of claim 3, wherein
    상기 음극 활물질은 이흑연화성 탄소; 난흑연화성 탄소; 천연 흑연; 인조 흑연; 탄소나노튜브; 그래핀; 실리콘; Sn 합금; Si 합금; Sn, Si, Ti, Ni, Fe 및 Li에서 하나 또는 둘 이상 선택되는 원소의 산화물; 또는 이들의 혼합물을 포함하는 이차전지용 전극의 제조방법.The negative active material is digraphitizable carbon; Non-graphitizable carbon; Natural graphite; Artificial graphite; Carbon nanotubes; Graphene; silicon; Sn alloys; Si alloys; Oxides of one or more elements selected from Sn, Si, Ti, Ni, Fe and Li; Or a method for producing a secondary battery electrode comprising a mixture thereof.
  16. 제 3항에 있어서, The method of claim 3, wherein
    상기 양극 활물질은 층상 구조의 리튬-금속 산화물; 스피넬 구조의 리튬-금속 산화물; 올리빈 구조의 리튬-금속 포스페이트; 또는 이들의 혼합물을 포함하는 이차전지용 전극의 제조방법.The positive electrode active material is a lithium-metal oxide of a layered structure; Spinel structure lithium-metal oxides; Lithium-metal phosphate of olivine structure; Or a method for producing a secondary battery electrode comprising a mixture thereof.
  17. 제 6항에 있어서,The method of claim 6,
    상기 활물질은 천연 흑연, 인조 흑연 또는 이들의 혼합물을 함유하는 이차전지용 전극의 제조방법.The active material is a method for producing a secondary battery electrode containing natural graphite, artificial graphite or a mixture thereof.
  18. 제 6항에 있어서,The method of claim 6,
    상기 활물질은 판형 또는 플레이크 형상을 포함하는 이차전지용 전극의 제조방법. The active material is a method of manufacturing an electrode for a secondary battery comprising a plate or flake shape.
  19. 제 2항에 있어서,The method of claim 2,
    상기 벌크제조단계는, 입자상의 전극 활물질로 전극 활물질 코어-탄소 전구체 쉘의 코어-쉘 구조의 복합 입자를 포함하는 원료를 가압 성형하여 성형체를 제조하는 단계; 및 상기 성형체를 열처리하여 상기 쉘의 탄소 전구체를 탄소로 열분해하는 단계를 포함하는 이차전지용 전극의 제조방법.The bulk manufacturing step may include forming a molded body by press-molding a raw material including composite particles having a core-shell structure of an electrode active material core-carbon precursor shell with a particulate electrode active material; And pyrolyzing the carbon precursor of the shell with carbon by heat-treating the molded body.
  20. 제 2항에 있어서,The method of claim 2,
    상기 벌크제조단계는 입자상의 전극 활물질 및 탄소 전구체를 포함하는 원료를 가압 성형하여 성형체를 제조하는 단계; 및 상기 성형체를 열처리하여 상기 탄소 전구체를 탄소로 열분해하는 단계;를 포함하는 이차전지용 전극의 제조방법.The bulk manufacturing step includes the steps of forming a molded body by press molding a raw material including a particulate electrode active material and a carbon precursor; And thermally decomposing the carbon precursor into carbon by heat-treating the molded body.
  21. 제 1항에 있어서,The method of claim 1,
    상기 절단단계 단계 후 결착단계 전, 또는 결착단계 후,After the cutting step step before the binding step, or after the binding step,
    상기 활물질 막의 적어도 일 표면을 표면 처리하는 단계가 더 수행되는 이차전지용 전극의 제조방법.Surface treatment of at least one surface of the active material film is a method of manufacturing a secondary battery electrode.
  22. 제 1항 내지 제 21항 중 어느 한 항의 제조방법으로 제조된 이차전지용 전극.A secondary battery electrode manufactured by the manufacturing method of any one of claims 1 to 21.
  23. 양극; 음극; 및 상기 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함하며,anode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution;
    상기 양극 및 음극에서 하나 이상 선택되는 전극은 전극 활물질을 함유하는 활물질 막, 집전체 및 상기 활물질 막을 집전체에 부착시키는 접착제를 포함하는 리튬 이차전지.At least one electrode selected from the positive electrode and the negative electrode includes an active material film containing an electrode active material, a current collector and an adhesive for attaching the active material film to the current collector.
  24. 양극; 음극; 및 상기 양극과 음극 사이에 개재된 분리막; 및 전해액;을 포함하며 상기 양극 및 음극에서 하나 이상 선택되는 전극에 포함된 활물질 막은 유기 바인더를 함유하지 않는 바인더-프리(binder-free) 막인 리튬 이차전지.anode; cathode; And a separator interposed between the anode and the cathode; And an electrolyte solution, wherein the active material film included in the at least one electrode selected from the positive electrode and the negative electrode is a binder-free film containing no organic binder.
  25. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막은 프리 스탠딩 막인 리튬 이차전지.The active material film is a free standing film lithium secondary battery.
  26. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막은 전극활물질을 함유하는 성형체 또는 소결체로부터 절단된 절단막인 리튬 이차전지.The active material film is a lithium secondary battery is a cut film cut from a molded or sintered body containing an electrode active material.
  27. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막은 활물질 막의 두께 방향을 기준하여 활물질 막 내 전극 활물질이 배향성을 갖는 리튬 이차전지.The active material film is a lithium secondary battery having an orientation of the electrode active material in the active material film based on the thickness direction of the active material film.
  28. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막은 전극 활물질의 입자간 넥(neck)이 형성된 리튬 이차전지.The active material film is a lithium secondary battery in which an interparticle neck of the electrode active material is formed.
  29. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막은 두께 방향 단면을 기준으로, 표면영역에서의 기공률과 중앙 영역에서의 기공률의 차의 절대값을 중앙 영역에서의 기공률로 나눈 비율이 10% 이하인 리튬 이차전지.The active material film has a ratio of dividing the absolute value of the difference between the porosity in the surface region and the porosity in the central region by the porosity in the central region based on the cross section of the thickness direction is 10% or less.
  30. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막은 열분해 탄소 및 도전재에서 선택되는 1종 이상을 더 포함하는 리튬 이차전지.The active material film further comprises at least one selected from pyrolytic carbon and a conductive material.
  31. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막의 겉보기 기공률은 10 내지 45%인 리튬 이차전지.An apparent porosity of the active material membrane is 10 to 45% lithium secondary battery.
  32. 제 23항에 있어서,The method of claim 23, wherein
    상기 접착제는 경화능을 갖는 수지를 포함하는 리튬 이차전지.The adhesive is a lithium secondary battery comprising a resin having a curing ability.
  33. 제 23항에 있어서,The method of claim 23, wherein
    상기 접착제는 전도성 접착제인 리튬 이차전지.The adhesive is a lithium secondary battery is a conductive adhesive.
  34. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 전극 활물질은 음극 활물질 또는 양극 활물질인 리튬 이차전지.The electrode active material is a lithium secondary battery that is a negative electrode active material or a positive electrode active material.
  35. 제 23 또는 제 24항에 있어서,The method of claim 23 or 24,
    상기 활물질 막의 표면에 위치하는 활물질은 잘린 입자상인 리튬 이차전지.An active material located on the surface of the active material film is a lithium secondary battery that is cut particles.
  36. 제 23항 또는 제 24항에 따른 리튬 이차전지를 포함하는 리튬 이차전지 모듈.A lithium secondary battery module comprising a lithium secondary battery according to claim 23 or 24.
  37. 제 23항 또는 제 24항에 따른 리튬 이차전지에 의해 전력이 공급되는 장치. Device powered by the lithium secondary battery according to claim 23 or 24.
PCT/KR2019/003006 2018-03-15 2019-03-15 Secondary battery electrode, and method for producing same WO2019177409A1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6007588A (en) * 1998-02-17 1999-12-28 Valence Technology, Inc. Methods for coating current collector with polymeric adhesives
KR20050027224A (en) * 2002-06-26 2005-03-18 산요덴키가부시키가이샤 Negative electrode for lithium secondary cell and lithium secondary cell
US20050271798A1 (en) * 2004-04-02 2005-12-08 Maxwell Technologies, Inc. Electrode formation by lamination of particles onto a current collector
KR20080098261A (en) * 2007-05-04 2008-11-07 한국과학기술연구원 Anode for secondary battery having negative active material with nano-fiber network structure and secondary battery using the same, and fabrication method of negative active material for secondary battery
KR20130043932A (en) * 2011-10-21 2013-05-02 삼성전기주식회사 Electric double layer capacitor
KR101572082B1 (en) 2013-12-24 2015-11-26 주식회사 엘지화학 Lithium Transition Metal Oxide With High Capacity and Lithium Secondary Battery Having the Same
KR101608635B1 (en) 2013-07-31 2016-04-05 주식회사 엘지화학 Anode Electrodes for Secondary Battery having High Capacity

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6007588A (en) * 1998-02-17 1999-12-28 Valence Technology, Inc. Methods for coating current collector with polymeric adhesives
KR20050027224A (en) * 2002-06-26 2005-03-18 산요덴키가부시키가이샤 Negative electrode for lithium secondary cell and lithium secondary cell
US20050271798A1 (en) * 2004-04-02 2005-12-08 Maxwell Technologies, Inc. Electrode formation by lamination of particles onto a current collector
KR20080098261A (en) * 2007-05-04 2008-11-07 한국과학기술연구원 Anode for secondary battery having negative active material with nano-fiber network structure and secondary battery using the same, and fabrication method of negative active material for secondary battery
KR20130043932A (en) * 2011-10-21 2013-05-02 삼성전기주식회사 Electric double layer capacitor
KR101608635B1 (en) 2013-07-31 2016-04-05 주식회사 엘지화학 Anode Electrodes for Secondary Battery having High Capacity
KR101572082B1 (en) 2013-12-24 2015-11-26 주식회사 엘지화학 Lithium Transition Metal Oxide With High Capacity and Lithium Secondary Battery Having the Same

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