WO2020080919A1 - Flexible secondary battery packaging, and flexible secondary battery comprising same - Google Patents

Flexible secondary battery packaging, and flexible secondary battery comprising same Download PDF

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Publication number
WO2020080919A1
WO2020080919A1 PCT/KR2019/013847 KR2019013847W WO2020080919A1 WO 2020080919 A1 WO2020080919 A1 WO 2020080919A1 KR 2019013847 W KR2019013847 W KR 2019013847W WO 2020080919 A1 WO2020080919 A1 WO 2020080919A1
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Prior art keywords
graphene oxide
layer
secondary battery
reduced graphene
flexible secondary
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PCT/KR2019/013847
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French (fr)
Korean (ko)
Inventor
권요한
임준원
엄인성
이재헌
Original Assignee
주식회사 엘지화학
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Publication of WO2020080919A1 publication Critical patent/WO2020080919A1/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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/124—Primary casings; Jackets or wrappings characterised by the material having a layered structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B32B27/308—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising acrylic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • 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
    • H01M10/04—Construction or 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/105—Pouches or flexible bags
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/117—Inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/121—Organic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
    • H01M50/133—Thickness
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/131—Primary casings; Jackets or wrappings characterised by physical properties, e.g. gas permeability, size or heat resistance
    • H01M50/136—Flexibility or foldability
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/14—Primary casings; Jackets or wrappings for protecting against damage caused by external factors
    • H01M50/141—Primary casings; Jackets or wrappings for protecting against damage caused by external factors for protecting against humidity
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2439/00—Containers; Receptacles
    • B32B2439/40—Closed containers
    • B32B2439/46—Bags
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2457/00—Electrical equipment
    • B32B2457/10—Batteries
    • 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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H01M50/186—Sealing members characterised by the disposition of the sealing members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/233—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by physical properties of casings or racks, e.g. dimensions
    • H01M50/24—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders characterised by physical properties of casings or racks, e.g. dimensions adapted for protecting batteries from their environment, e.g. from corrosion
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a flexible secondary battery packaging and a flexible secondary battery comprising the same.
  • a secondary battery is a device that converts and stores external electrical energy into chemical energy and then generates electricity when needed.
  • the name "rechargeable battery” is also used to mean that it can be charged multiple times.
  • Commonly used secondary batteries include lead-acid batteries, nickel-cadmium batteries (NiCd), nickel-metal hydride batteries (NiMH), lithium-ion batteries (Li-ion), and lithium-ion polymer batteries (Li-ion polymer). Secondary batteries offer both economic and environmental advantages over primary batteries that are used once and discarded.
  • Secondary batteries are currently used where low power is used. For example, there are devices, portable devices, tools, and uninterruptible power supplies to help start the car. Recently, the development of wireless communication technology has led to the popularization of portable devices, and there is also a tendency to wirelessize many types of conventional devices, and the demand for secondary batteries is exploding. In addition, hybrid vehicles and electric vehicles have been put into practical use in terms of prevention of environmental pollution, and these next-generation vehicles employ technology that reduces the value, weight, and extends the life span by using a secondary battery.
  • Cylindrical, prismatic, and pouch-type secondary batteries are known as secondary battery types, and recently, flexible secondary batteries featuring flexibility, including a cable-type secondary battery, which is a battery having a very large ratio to the cross-sectional diameter, are proposed. Became.
  • the flexible secondary battery 50 is provided with a negative electrode 10 wound around a coil and provided in a cylindrical shape, and provided with a negative electrode 10 on one side to surround the other side of the negative electrode 10. It includes a separator 20, an anode 30 provided on the other side of the separator 20, and a packaging 40 provided in a cylindrical shape and provided with an anode 30 on one side. That is, the flexible secondary battery 50 is prepared by sequentially winding the separator 20, the anode 30, and the packaging 40 on the other side of the cathode 10 provided in a coil shape. In this way, the flexible secondary battery 50 is provided in a cable shape so that it can be bent.
  • FIG. 2 is a packaging for a flexible secondary battery including a laminate film and a heat shrink tube, a state before applying heat to the packaging for the flexible secondary battery.
  • a laminate film 50 including a sealant polymer layer 2 on both sides of a predetermined support layer 1 and the support layer 1 surrounds the outer surface of the electrode assembly so that a predetermined portion overlaps.
  • the outer heat shrink tube 60 is present. When heat is applied after this, the heat-shrinkable tube contracts tightly and tightly wraps the laminate film surrounding the electrode assembly and the heat-shrinkable tube.
  • the heat-shrinkable tube is generally made of a polymer material as a main component. Since these polymers are made porous due to their structural characteristics, there is a problem that moisture, air, and the like are easily introduced into the battery. The inflow of moisture into the battery is a major cause of deterioration of the performance of the battery by reaction with moisture in the electrolyte solution using LiPF 6 as a lithium salt.
  • one problem to be solved in the present invention is to improve the moisture barrier properties of the heat-shrinkable tube when the heat-shrinkable tube is included in the flexible secondary battery packaging.
  • Another problem to be solved in the present invention is to improve the moisture barrier properties of the heat-shrinkable tube while ensuring flexibility of the flexible secondary battery.
  • Another problem to be solved in the present invention is to provide a flexible secondary battery with improved moisture barrier properties of the heat shrink tube.
  • the packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly, the packaging for the flexible secondary battery, A moisture barrier film comprising a reduced graphene oxide (rGO) layer comprising a plurality of reduced graphene oxide sheets and a sealant layer located on at least one of the one side and the other side of the reduced graphene oxide; And a polymer heat shrink tube surrounding the outermost side of the moisture barrier film, wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer form electrostatic interactions between the reduced graphene oxide sheets adjacent to each other.
  • Packaging for a flexible secondary battery is provided, which is characterized in that.
  • the reduced graphene oxide sheet is provided with a flexible secondary battery packaging, characterized in that it has a layer structure of 1 to 3 reduced graphene oxide particles.
  • the reduced graphene oxide sheet in the first aspect or the second aspect, is provided with a packaging for a flexible secondary battery, characterized in that it has a thickness in the range of 0.1 to 10 ⁇ m.
  • the reduced graphene oxide sheet in any one of the first to third aspects is Li + , K + , Ag + , Mg 2 + , Ca 2 + , Cu 2 + , Pb 2 + , Co 2+ , Al 3 + , Cr 3 + , Fe 3 + or two or more of these are provided for packaging a flexible secondary battery, characterized in that it forms an electrostatic interaction with the adjacent reduced graphene oxide sheet. .
  • the moisture barrier film includes a sealant layer located on one side of the reduced graphene oxide, and the reduced graphene oxide layer Further comprising a mechanical support layer located on the other side of the, both ends are formed in a tubular shape surrounding the outer surface of the electrode assembly in the form of overlapping, the opposite sealant layers of the water barrier film overlapping each other are heat-pressed and sealed Packaging is provided for a flexible secondary battery, characterized in that the sealing portion forms a folded wing portion along the periphery of the moisture barrier film.
  • At least one of the mechanical support layer and the reduced graphene oxide layer, and between the reduced graphene oxide layer and the sealant layer in any one of the first to fifth aspects Packaging for a flexible secondary battery further comprising an adhesive layer is provided.
  • the moisture barrier film includes two sealant layers located on one side and the other side of the reduced graphene oxide layer,
  • the two sealant layers are a first sealant layer located on one side of the reduced graphene oxide layer and a second sealant layer located on the other side of the reduced graphene oxide layer, and a first of one end surface of the moisture barrier film
  • a packaging for a flexible secondary battery is provided in which a sealant layer and a second sealant layer on the other end of the other end overlap and adhere to each other.
  • packaging for a flexible secondary battery is further provided, further comprising a mechanical support layer between the reduced graphene oxide layer and the second sealant layer.
  • the mechanical support layer and the second sealant layer Packaging for a flexible secondary battery further comprising an adhesive layer on at least one of the gaps is provided.
  • the packaging for a flexible secondary battery in which the reduced graphene oxide layer has a thickness in the range of 20 nm to 30 ⁇ m in any one of the first to ninth aspects.
  • a method of manufacturing a packaging for a flexible secondary battery surrounding an outer surface of the flexible secondary battery electrode assembly
  • Graphene oxide Graphene Oxide (GO) coated with a dispersion composition in which particles and metal salts are dispersed and dried on the sealant layer to form a reduced graphene oxide (rGO), the sealant Forming a moisture barrier film having a reduced graphene oxide layer formed on one surface of the layer;
  • a method of manufacturing a packaging for a flexible secondary battery according to the first aspect comprising a.
  • a method for manufacturing a flexible secondary battery packaging method in which the graphene oxide layer is reduced by iodic acid or vitamin C in the twelfth aspect is provided.
  • the moisture barrier film includes two sealant layers located on one side and the other side of the reduced graphene oxide layer, and the two sealant layers are the reduced graphene A first sealant layer located on one side of the pin oxide layer and a second sealant layer located on the other side of the reduced graphene oxide layer, and a first sealant layer on one end of the moisture barrier film and a second sealant on the other end A method of manufacturing a flexible secondary battery packaging in which a sealant layer is adhered to each other by overlapping a predetermined portion is provided.
  • the electrode assembly in the thirteenth aspect of the invention, the electrode assembly; A flexible secondary battery including; packaging for the flexible secondary battery of claim 1 surrounding the outer surface of the electrode assembly is provided.
  • a moisture barrier film is present between the electrode assembly and the heat shrink tube, so that moisture and / or gas flowing into the secondary battery can be prevented.
  • the packaging for a flexible secondary battery of the present invention includes a reduced graphene oxide layer in the moisture barrier film.
  • the reduced graphene oxide layer in contrast to the fact that several water monolayers exist between the graphene oxide interlayers, such that moisture and / or gas molecules cannot be blocked, the reduced graphene oxide layer according to the present invention Silver, an electrostatic interaction is formed between the reduced graphene oxide sheets constituting the reduced graphene oxide layer, thereby effectively blocking a path through which moisture and / or gas can be introduced.
  • the packaging material for the flexible secondary battery itself may have flexibility, and thus stress generated when the flexible secondary battery is bent can be alleviated.
  • FIG. 1 is a view showing the structure of an embodiment of a general flexible secondary battery.
  • FIG. 2 is a cross-sectional view schematically showing an embodiment of a general flexible secondary battery inserted into a heat-shrinkable tube but before being heat-treated.
  • FIG 3 is a cross-sectional view schematically showing a moisture barrier film according to an embodiment of the present invention.
  • FIG. 4 is a cross-sectional view schematically showing a moisture barrier film according to an embodiment of the present invention.
  • FIG. 5 is a cross-sectional view schematically showing a moisture barrier film according to an embodiment of the present invention.
  • FIG. 6 is an internal cross-sectional view schematically showing a reduced graphene oxide layer according to an embodiment of the present invention.
  • FIG. 7 is a cross-sectional view schematically showing an embodiment in which a moisture barrier film and a heat shrinkable tube are applied to an electrode assembly according to an embodiment of the present invention.
  • FIG. 8 is a cross-sectional view schematically showing an embodiment in which a moisture barrier film and a heat shrinkable tube are applied to an electrode assembly according to an embodiment of the present invention.
  • Example 9 is a graph showing the cycle performance of the secondary battery produced in Example 3 and Comparative Example 4.
  • graphene means that a plurality of carbon atoms are covalently linked to each other to form a polycyclic aromatic molecule, wherein the covalently linked carbon atoms form a six-membered ring as a basic repeating unit. It forms, but it is also possible to further include a 5-membered ring and / or a 7-membered ring. Therefore, the sheet formed by the graphene may be seen as a single layer of carbon atoms covalently bonded to each other, but may not be limited thereto.
  • the sheet formed by the graphene may have various structures, and such a structure may vary depending on the content of the 5-membered ring and / or 7-membered ring that may be included in the graphene.
  • a structure may vary depending on the content of the 5-membered ring and / or 7-membered ring that may be included in the graphene.
  • the sheet formed by the graphene when they is composed of a single layer, they may be stacked with each other to form a plurality of layers, and the side ends of the graphene sheet may be saturated with hydrogen atoms, but may not be limited thereto.
  • graphene oxide is also called graphene oxide and may be abbreviated as "GO”.
  • the monolayer graphene may include a structure in which a functional group containing oxygen, such as a carboxyl group, a hydroxy group, or an epoxy group, is combined, but may not be limited thereto.
  • reduced graphene oxide refers to graphene oxide having a reduced oxygen ratio through a reduction process, and may be abbreviated as “rGO”, but may not be limited thereto.
  • oxygen content included in the reduced graphene oxide may include 0.01 to 30 atomic% (at.%) Of oxygen relative to 100% of carbon atoms, but is not limited thereto.
  • the interlayer spacing of the reduced graphene oxide sheet may be measured using an XRD device and calculated by calculating the Brag equation, and the XRD device may use Bruker's D4 Endeavor.
  • the thickness of the reduced graphene oxide layer may be determined by observing the cross section of the synthesized reduced graphene oxide layer using an SEM device, and Hitachi 4800 may be used as the SEM device.
  • the thickness of the reduced graphene oxide sheet may be measured using an atomic force microscope (AFM) device after spin-casting the reduced graphene oxide sheet on an SiO 2 substrate, and the Park Systems' NX10 can be used as the AFM device.
  • AFM atomic force microscope
  • the packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly, and the packaging for the flexible secondary battery is a plurality of reduction A moisture barrier film comprising a reduced graphene oxide (rGO) layer comprising a graphene oxide sheet and a sealant layer located on at least one of the one side and the other side of the reduced graphene oxide; And a polymer heat shrink tube surrounding the outermost side of the moisture barrier film, wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer form electrostatic interactions between the reduced graphene oxide sheets adjacent to each other.
  • Packaging for a flexible secondary battery is provided, which is characterized in that.
  • the packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly, and packaging for the flexible secondary battery
  • a moisture barrier film comprising a reduced graphene oxide (rGO) layer comprising a plurality of reduced graphene oxide sheets and a sealant layer located on one side of the reduced graphene oxide layer
  • a mechanical support layer located on the other side of the moisture barrier film
  • a polymer heat-shrinkable tube surrounding the outermost side of the moisture barrier film, wherein opposing sealant layers at both ends of the moisture barrier film are thermocompressed to form a sealing portion, and the sealing portion is around the moisture barrier film.
  • the packaging for the flexible secondary battery comprising a plurality of reducing graphene oxide sheets (reduced A moisture barrier film comprising a graphene oxide (rGO) layer and two sealant layers located on one side and the other side of the reduced graphene oxide layer; And a polymer heat shrink tube surrounding the outermost side of the moisture barrier film, wherein the two sealant layers are located on one side of the reduced graphene oxide layer and on the other side of the reduced graphene oxide layer.
  • the first sealant layer on one end of the moisture barrier film and the second sealant layer on the other end of the other end are adhered to each other by overlapping each other, and in the reduced graphene oxide layer, the plurality of The reduced graphene oxide sheet is provided with a packaging for a flexible secondary battery, characterized in that it forms an electrostatic interaction between the reducing graphene oxide sheet adjacent to each other.
  • electrostatic interaction is understood to include ionic bonding.
  • the packaging for the flexible secondary battery of the present invention comprises i) a moisture barrier film and ii) a heat shrink tube.
  • the mechanical support layer 110 An adhesive layer 120a located on the other side of the mechanical support layer 110; A reduced graphene oxide layer 130 located on the other side of the adhesive layer 120a; And an adhesive layer 120b located on the other side of the reduced graphene oxide layer 130. And a sealant layer 150 positioned on the other side of the adhesive layer 120a sequentially positioned in the thickness direction. At least one layer of the adhesive layers 120a and 120b may be omitted. For example, when the affinity between the mechanical support layer 110 and the reduced graphene oxide layer 130 is good or excellent, the adhesive layer 120a between the mechanical support layer 110 and the reduced graphene oxide layer 130 may be omitted. .
  • the moisture barrier film F of FIG. 4 includes a first sealant layer 240a, a first adhesive layer 220a, a mechanical support layer 210, a second adhesive layer 220b, a reduced graphene oxide layer 230, and 3 may have a structure in which the adhesive layer 220c and the second sealant layer 240b are sequentially positioned in the thickness direction.
  • At least one layer of the adhesive layers 220a, 220b, and 220c may be omitted.
  • the adhesive layer 220b between the mechanical support layer 210 and the reduced graphene oxide layer 230 may be omitted.
  • the moisture barrier film (F) of the present invention may not include a mechanical support layer. That is, as shown in Figure 5, another embodiment of the moisture barrier film (F) of the present invention is a first sealant layer (340a), the first adhesive layer located on the other side of the first sealant layer (340a) ( 320a), a reduced graphene oxide layer 330 located on the other side of the first adhesive layer 320a, a second adhesive layer 320b located on the other side of the reduced graphene oxide layer 330, and the second adhesive layer
  • the second sealant layer 340b positioned on the other side of the 320b may have a structure sequentially positioned in the thickness direction.
  • the mechanical support layer serves to prevent the moisture barrier film from being torn or damaged against external stress or impact, and can be used without limitation as long as it is a material having such a mechanical property.
  • Non-limiting examples of materials constituting the mechanical support layer high density polyethylene, low density polyethylene, linear low density polyethylene, ultra high molecular weight polyethylene, polyolefins such as polypropylene; Polyesters such as polyethylene terephthalate and polybutylene terephthalate; Polyacetal; Polyamide; Polycarbonate; Polyimide; Polyetheretherketone; Polyethersulfone; Polyphenylene oxide; Polyphenylenesulfide; And polyethylene naphthalate (polyethylenenaphthalate); may be mentioned one or a mixture of two or more selected from the group consisting of, but is not limited thereto.
  • the mechanical support layer can optionally be modified to a hydrophilic surface by oxygen or nitrogen plasma treatment.
  • a hydrophilic surface by oxygen or nitrogen plasma treatment.
  • surface energy is generated due to a difference between the hydrophobicity of the surface of the mechanical support layer and the hydrophilicity of graphene oxide, and as a result, graphene oxide is formed on one surface of the mechanical support layer. It may be difficult to ensure a uniform coating of the layer.
  • the surface of a mechanical support layer having a hydrophobic surface can be surface modified with hydrophilicity.
  • the surface modification may be performed by UV-ozone treatment, plasma surface treatment using oxygen or nitrogen, chemical treatment using a silane coupling agent such as amino silane, or surface coating using a polymer or organic compound, but is not limited thereto. .
  • the reduced graphene oxide layer may be formed directly on one surface of the mechanical support layer or with an adhesive layer therebetween.
  • the reduced graphene oxide layer is a component that enables the packaging for a flexible secondary battery according to the present invention to block the inflow of moisture and / or gas.
  • the blocking effect may be influenced by factors such as the thickness of the graphene oxide layer and the degree of graphene oxide alignment, and these may be determined according to process conditions for producing reduced graphene oxide.
  • the process conditions include, but are not limited to, the purity of the graphene oxide, the concentration of the graphene oxide dispersion composition, the coating time and the number of coatings, the evaporation rate of the solvent after coating, the presence or absence of shear force, and the like.
  • the reduced graphene oxide layer may directly or directly disperse a dispersion composition in which graphene oxide (GO) particles and metal salts are dispersed on one surface of a mechanical support layer. It can be obtained by coating and drying the adhesive layer therebetween to form a graphene oxide layer, and reducing the formed graphene oxide layer.
  • the mechanical barrier is not included in the moisture barrier film
  • the graphene oxide particles and the metal salt are dispersed to coat and dry the graphene oxide dispersion composition directly on one surface of the sealant layer or with an adhesive layer therebetween and reduce it. Can be obtained.
  • a plurality of reduced graphene oxide particles 2310 for example, reduced graphene oxide flat particles are stacked to reduce graphene oxide
  • a sheet 2320 is formed, and a plurality of reduced graphene oxide sheets 2320 formed as described above form a reduced graphene oxide layer.
  • the reduced graphene oxide sheet 2320 is adjacent to a metal cation. It forms an electrostatic interaction 2320 with the reduced graphene oxide sheet.
  • the metal cation interacts electrostatically with oxygen functional groups present at the edge portion of the reduced graphene oxide particles. Since the oxygen functional group has a (-) charge and a metal cation has a (+) charge, a cation having an oxidation number of 2+ or more to have sufficient attraction due to electrostatic interaction between two or more reduced graphene oxide particles This is preferred. In addition, since the attraction force between the metal cation and the reduced graphene oxide particles is an interaction occurring at the edge of the reduced graphene oxide particles, the spacing between the reduced graphene oxide sheets in the basal plane portion is maintained.
  • the reduced graphene oxide sheet may be in the form of a layer structure of 1 to 3 reduced graphene oxide particles, for example, reduced graphene oxide platelet particles.
  • the layer structure of the reduced graphene oxide should be made before the reduction reaction of the graphene oxide.
  • graphene oxide is synthesized after oxidizing graphite through an ultrasonic dispersion process. By controlling the degree of oxidation of graphite in the step of oxidizing graphite, it is possible to control the number of stacked graphene oxide particles.
  • the layer structure of the reduced graphene oxide particles is as described above, the probability of occurrence of defects when coating the reduced graphene oxide is significantly reduced, and an effect of improving the mechanical properties of the prepared reduced graphene oxide layer occurs. .
  • the reduced graphene oxide sheet may have a thickness in the range of 0.002 to 10 ⁇ m, or 0.005 to 1 ⁇ m, or 0.01 to 0.1 ⁇ m.
  • the reduced graphene oxide sheet may have flexible mechanical properties and effective moisture blocking effect.
  • graphene oxide having a certain level of purity or more it is preferable to use graphene oxide having a certain level of purity or more to obtain a dense interlayer spacing.
  • graphene oxide having a purity of 93% or higher, or a purity of 97.5% or higher, or 99.5% or higher may be used.
  • the term “purity” in the present specification means a weight ratio of graphene oxide to weight combined with graphene oxide and metal residue.
  • the graphene oxide is dispersed in a dispersion medium such as water to obtain a dispersion composition.
  • a metal salt and graphene oxide are dispersed in a dispersion medium such as water or deionized water to obtain a dispersion composition.
  • the metal cation constituting the metal salt is Li + , K + , Ag + , Mg 2 + , Ca 2 + , Cu 2 + , Pb 2 + , Co 2 + , Al 3 + , Cr 3 + , Fe 3 + or two or more of them.
  • the metal cation Al 3 + , Cr 3 + , or Fe 3 + is particularly preferable because it has a high oxidation number and can effectively exhibit electrostatic attraction.
  • Anion constituting the metal salt with said metal cation is not particularly limited as to meet the object of the present invention, non-limiting examples of Cl - may be, or SO 4 2- -, NO 3.
  • the metal salt may be added to the dispersion medium in an amount ranging from 0.01 to 10% by weight or 0.01 to 1% by weight based on the weight of the graphene oxide particles.
  • the metal salt is used in an amount in the above-described range, when an excessive amount of metal cations is introduced, a nanometer-level gap between reducing graphene sheets is prevented due to formation of metal particles, and at the same time, proper electrostatic interaction is obtained. You can.
  • the dispersion composition may include graphene oxide in an amount of about 0.0001 parts by weight to about 0.01 parts by weight based on 100 parts by weight of the dispersion medium.
  • the amount of graphene oxide is included in an amount in the above numerical range, it is contained more than 0.0001 parts by weight to induce the alignment of graphene oxide when the graphene oxide layer is formed, and is used in an amount of 0.01 parts by weight or less to disperse It can obtain the effect of securing.
  • the graphene oxide dispersion composition is about 0.0001 parts by weight to about 0.01 parts by weight, about 0.0004 parts by weight to about 0.01 parts by weight, about 0.0004 parts by weight to about 0.008 parts by weight, based on 100 parts by weight of the dispersion medium, Or it may be prepared to include from about 0.0004 parts by weight to about 0.006 parts by weight, but may not be limited thereto.
  • the dispersion may be an ultrasonic generator such as an ultrasonic disperser, but may not be limited thereto.
  • the graphene oxide dispersion composition may further include an organic solvent capable of graphene oxide dispersion.
  • organic solvent include alcohol, dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (N-methyl pyrrolidone), methyl phenol (methyl phenol, It may be a cresol (cresol) or a mixture of two or more of them, but may not be limited to this.
  • the graphene oxide dispersion composition is less than about 100% by volume of the graphene oxide dispersion with respect to 100% by volume of the dispersion medium It may be to further include this possible organic solvent, for example, the graphene oxide dispersion composition is about 1% by volume to about 100% by volume, about 20% by volume to about 100% by volume relative to 100% by volume of the dispersion medium, 20% by volume to about 60% by volume, or about 40% by volume to about 60% by volume, may be to further include an organic solvent capable of dispersing the graphene oxide, but
  • the graphene oxide dispersion composition is coated on a mechanical support layer or a sealant layer.
  • Non-limiting examples of the coating method bar coating (rod coating), spin casting (spin-casting), drop-casting (drop-casting), vacuum filtering (vacuum filtering), deep coating (dip-coating) or electrophoretic coating (electrophoretic coating) may be used.
  • the coating induces alignment of graphene oxide by securing a coating time of 1 second or longer to obtain a dense film, and 1 second to 30 minutes, or 3 seconds in order to expect an effect to obtain a uniform film with a coating time within 30 minutes. To 10 minutes, or 5 seconds to 5 minutes.
  • the coating can securely form a sufficient graphene oxide layer by securing the number of coatings one or more times, and in order to expect an effect for suppressing the formation of a thick layer unnecessarily with the number of coatings within 30 times, 1 to It may be coated over 30 times, or 1 to 10 times, or 1 to 5 times.
  • the amount of graphene oxide dispersion composition 1 mL to 1000 mL, or 3 mL to 200 mL, or 10 mL to 100 mL may be used in one coating.
  • the dried graphene oxide layer has an effect of securing moisture barrier properties by having a thickness of 20 nm or more, and securing mechanical properties by having a thickness of 30 ⁇ m or less, and this effect
  • the dried graphene oxide layer may have a thickness in the range of 20 nm to 30 ⁇ m, or 100 nm to 10 ⁇ m, or 500 nm to 5 ⁇ m.
  • the obtained graphene oxide layer is reduced to maximize the moisture barrier properties of the moisture barrier film, thereby forming a reduced graphene oxide layer.
  • a reduction method using iodic acid (HI) or a reduction method using vitamin C may be performed.
  • the container containing the iodic acid solution and the prepared graphene oxide layer are put together in a closed space, such as a glass petri dish, for 1 minute to 1 hour at a temperature in the range of 10 ° C to 100 ° C
  • the graphene oxide is converted into reduced graphene oxide by the step of vaporizing iodic acid, and maintaining the graphene oxide layer together with the vaporized iodic acid for 2 minutes to 3 hours, thereby reducing the graphene oxide layer.
  • a closed space such as a glass petri dish
  • the graphene oxide layer is impregnated with a solution of iodic acid at 10 to 100 ° C, such as 90 ° C, so that the graphene oxide layer is converted into a reduced graphene oxide layer, and washing the reduced graphene oxide layer with distilled water.
  • a reduced graphene oxide layer can be obtained.
  • the reduced graphene oxide layer obtained can be washed with ethanol.
  • the reduced graphene oxide layer obtained from the above has a structure capable of blocking the inflow of moisture and / or gas, for example, a reduced graphene oxide sheet interlayer spacing in the range of 0.3 nm to 5.0 nm, or 0.3 nm to 0.7 nm.
  • a reduced graphene oxide sheet interlayer spacing in the range of 0.3 nm to 5.0 nm, or 0.3 nm to 0.7 nm.
  • interlayer spacing refers to the spacing between sheets of reduced graphene oxide, that is, the spacing between sheets of reduced graphene oxide.
  • the electrode assembly may be blocked from the outside after surrounding the outer surface of the electrode assembly.
  • the sealant layer has a heat-adhesive or heat-sealable adhesive adhered by heat, and each independently polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, polypropylene chloride, polypropylene-butylene-ethylene terpolymer, poly It may include at least one or more selected from the group consisting of propylene, polyethylene and ethylene propylene copolymer, but is not limited thereto.
  • the mechanical support layer, the reduced graphene oxide A layer may further include an adhesive layer between the sealant layers facing each other.
  • the material of the adhesive layer includes, for example, a composition containing a urethane-based material, an acrylic material, and a thermoplastic elastomer, but is not limited thereto.
  • the moisture barrier film having the above-described structure may have a thickness in the range of 1 ⁇ m to 1000 ⁇ m, or 10 ⁇ m to 500 ⁇ m, or 20 ⁇ m to 200 ⁇ m.
  • 10 -6 g / m 2 / day to 10 -3 g / m 2 / day, or 10 -6 g / m 2 / day to 10 -4 g / m 2 / day, or 10 -6 g / It may have a water vapor transmission rate (WVTR) in the range of m 2 / day to 10 -5 g / m 2 / day. Therefore, it is possible to meet the moisture barrier properties required in secondary battery packaging.
  • WVTR water vapor transmission rate
  • WVTR water vapor permeation rate
  • the packaging for the flexible secondary battery further includes a heat shrink tube in addition to the moisture barrier film, and non-limiting embodiments thereof are illustrated in FIGS. 8 and 9.
  • the outer surface of the electrode assembly (C) is surrounded by a moisture barrier film (F), the sealant layer 400 is disposed to face the electrode assembly.
  • the moisture barrier film forms a tube that surrounds the outer surface of the electrode assembly in a form in which predetermined portions of both ends overlap, and opposing sealant layers of both ends overlapping each other of the moisture barrier film are thermally compressed to form a sealing portion.
  • the sealing portion forms a folded wing portion along the periphery of the moisture barrier film. Then, a heat shrink tube (T) is applied.
  • the outer surface of the electrode assembly (C) is surrounded by a moisture barrier film (F), the first sealant layer (not shown) and the second sealant layer (not shown) on each side of the other side of the moisture barrier film It is equipped.
  • the moisture barrier film is in the form of a tube surrounding the outer surface of the electrode assembly, and the first sealant layer on one end of the moisture barrier film and the second sealant layer on the other end of the other end portion are adhered to each other by overlapping each other. Then, a heat shrink tube (T) is applied.
  • the term 'predetermined portion' means that when the moisture barrier film surrounds the outer surface of the electrode assembly, the length of the moisture barrier film is longer than the circumference of the electrode assembly, so that the sealant layer of the moisture barrier film overlaps. It means to exist.
  • the predetermined portion may be 1 to 99%, or 1 to 70%, or 3 to 50%, or 5 to 30% around the outer surface of the electrode assembly.
  • the heat-shrinkable tube is a tube that contracts when heated, and means a material that tightly wraps a terminal or a material having a different shape or size.
  • the moisture barrier film is partially wrapped on the outer surface of the electrode assembly, and when heat is applied after being inserted into the heat shrink tube, the sealing polymer of the moisture barrier film is melted by heat transmitted through the heat shrink tube and the moisture barrier film melts. The sealing proceeds, and at the same time, the heat-shrinkable tube is shrunk while being heated, thereby providing tight packaging tightly between the heat-shrinkable tube and the moisture barrier film surrounding the outer surface of the electrode assembly.
  • the moisture barrier performance of the packaging is further improved, and the effect of insulation can be obtained simultaneously through the heat shrink tube.
  • the heat-shrinkable tube is a commercialized heat-shrinkable tube having various materials and shapes, it can be easily obtained and used for the purpose of the present invention.
  • the temperature of the shrinking process To avoid thermal damage to the secondary battery, it is necessary to reduce the temperature of the shrinking process to a low temperature, and generally shrink to a temperature of 70 to 200 ° C, or 70 to 150 ° C, or 100 to 150 ° C, or 70 to 120 ° C It is required to be completed.
  • the heat shrink layer is selected from the group consisting of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, fluororesins such as polyvinylidene fluoride and polytetrafluoroethylene, and polyvinyl chloride. It can be formed from any one, or a polymer modified two or more of them.
  • a flexible secondary battery including the packaging for the flexible secondary battery is provided.
  • the flexible secondary battery according to the present invention has a horizontal cross section of a predetermined shape including an internal electrode, a separation layer to prevent shorting of an electrode formed surrounding the internal electrode, and an external electrode formed around an outer surface of the separation layer. Electrode assembly extended to; And packaging for a flexible type flexible secondary battery according to the present invention, which is in close contact with the entire outer surface of the electrode assembly.
  • the term 'predetermined shape' means that the shape is not particularly limited, and that any shape that does not impair the essence of the present invention is possible.
  • the horizontal cross-section of the predetermined shape may be circular or polygonal, and the circular structure is a geometrically complete symmetrical circular shape and an asymmetrical oval shape.
  • the polygonal structure is not particularly limited, and non-limiting examples of the polygonal structure may be triangular, square, pentagonal or hexagonal.
  • the flexible secondary battery of the present invention has a horizontal cross-section of a predetermined shape, has a linear structure elongated in the longitudinal direction of the horizontal cross-section, has flexibility and is free from deformation.
  • the internal electrode of the electrode assembly is a lithium ion supply core portion including an electrolyte, an internal current collector having an open structure formed surrounding an outer surface of the lithium ion supply core portion, and an internal electrode formed on the surface of the internal current collector.
  • An active material layer may be provided.
  • the open structure refers to a structure in which the open structure is used as a boundary surface, and the material can be freely moved from inside to outside through the boundary surface.
  • the lithium ion supply core portion may include an electrolyte, and the type of the electrolyte is not particularly limited, but ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and vinylene carbonate (VC) are not limited.
  • EC ethylene carbonate
  • PC propylene carbonate
  • BC butylene carbonate
  • VC vinylene carbonate
  • DEC Diethyl carbonate
  • DMC dimethyl carbonate
  • EMC ethyl methyl carbonate
  • MF gamma-butyrolactone
  • ⁇ -BL gamma-butyrolactone
  • MP methyl propionate
  • PEO Polypropylene oxide
  • PI polyethylene imine
  • PES polyethylene sulphide
  • PVAc polyvinyl acetate
  • the electrolyte may further include a lithium salt, such as LiCl, LiBr, LiI, LiClO4, LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, chloroboranlithium, lower aliphatic lithium carboxylate, lithium tetraphenylborate, and the like are preferably used.
  • the lithium ion supply core portion may be composed of only an electrolyte, and in the case of a liquid electrolyte, it may also be configured using a porous carrier.
  • the internal current collector of the present invention has an open structure to facilitate the penetration of the electrolyte in the lithium ion supply core, and such an open structure can be adopted as long as the structure has an easy penetration of the electrolyte.
  • the internal current collector is a surface treated with carbon, nickel, titanium, or silver on the surface of stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel, and a vision treated with aluminum-cadmium alloy and a conductive material. It is preferable to use a conductive polymer or a conductive polymer.
  • the current collector serves to collect electrons generated by the electrochemical reaction of the active material or to supply electrons necessary for the electrochemical reaction, and generally metals such as copper or aluminum are used.
  • metals such as copper or aluminum are used.
  • a non-conductive polymer surface-treated with a conductive material or a polymer conductor made of a conductive polymer it is relatively more flexible than a metal such as copper or aluminum.
  • the conductive material examples include polyacetylene, polyaniline, polypyrrole, polythiophene and polysulfurnitride, ITO (Indum Thin Oxide), silver, palladium, and nickel, and conductive polymers include polyacetylene, polyaniline, polypyrrole, and polyt Offen and polysulfuride can be used.
  • the non-conductive polymer used in the current collector is not particularly limited.
  • the inner electrode active material layer of the present invention is formed on the surface of the inner current collector. At this time, it is formed around the outer surface of the inner current collector, as well as when the inner current collector open structure is not exposed to the outer surface of the inner electrode active material layer, the inner electrode active material layer is formed on the surface of the open structure of the inner current collector Also included is the case where the open structure of the inner current collector is exposed to the outer surface of the inner electrode active material layer. For example, a case where an active material layer is formed on the surface of a wound wire-type current collector and a case where a wire-type current collector having an electrode active material layer is formed by winding are used.
  • the external current collector of the present invention is not particularly limited in form, but a pipe-type current collector, a wound wire-type current collector, or a mesh-type current collector can be used.
  • the external current collector may include stainless steel, aluminum, nickel, titanium, calcined carbon, and copper; Stainless steel surface-treated with carbon, nickel, titanium or silver; Aluminum-cadmium alloy; A non-conductive polymer surface-treated with a conductive material; Conductive polymers; A metal paste containing a metal powder that is Ni, Al, Au, Ag, Al, Pd / Ag, Cr, Ta, Cu, Ba or ITO; Alternatively, a carbon paste containing carbon powder that is graphite, carbon black, or carbon nanotubes may be used.
  • the internal electrode may be a cathode or an anode
  • the external electrode may be an anode or a cathode corresponding to the external electrode
  • the electrode active material layer of the present invention functions to move ions through a current collector, and the movement of these ions is caused by interaction through absorption of ions from the electrolyte layer and release of ions to the electrolyte layer.
  • the electrode active material layer is natural graphite, artificial graphite, carbonaceous material; Lithium-containing titanium composite oxides (LTO), metals (Me) which are Si, Sn, Li, Zn, Mg, Cd, Ce, Ni, or Fe; Alloys composed of the metals (Me); Oxides (MeO x ) of the metals (Me); And may include a complex of the metal (Me) and carbon, as a positive electrode active material layer LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCoPO 4 , LiFePO 4 , LiNiMnCoO 2 And LiNi 1 -xyz Co x M1 y M2 z O 2 (M1 and M2 are each independently selected
  • the separation layer of the present invention may use an electrolyte layer or a separator.
  • the electrolyte layer used as a passage for these ions is a gel polymer electrolyte or PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES), or polyvinyl acetate (PVAc) using PEO, PVdF, PMMA, PAN or PVAC
  • PEO polypropylene oxide
  • PEI polyethylene imine
  • PES polyethylene sulphide
  • PVAc polyvinyl acetate
  • the matrix of the solid electrolyte is preferably a polymer or ceramic glass as a basic skeleton. In the case of a general polymer electrolyte, even if the ionic conductivity is satisfied, the ions can move very slowly in terms of reaction rate.
  • an electrolyte of a gel polymer that facilitates ionic movement than a solid. Since the gel polymer electrolyte is not excellent in mechanical properties, a pore structure support or a crosslinked polymer may be included to compensate for this. Since the electrolyte layer of the present invention can function as a separator, a separate separator may not be used.
  • the electrolyte layer of the present invention may further include a lithium salt.
  • Lithium salt may improve the ionic conductivity and reaction rate, and non-limiting examples of these include LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloro may borane lithium, lower aliphatic carboxylic acid lithium, and tetraphenyl lithium borate available .
  • the separator is not limited to the type, but is made of a polyolefin-based polymer selected from the group consisting of ethylene homopolymer, propylene homopolymer, ethylene-butene copolymer, ethylene-hexene copolymer and ethylene-methacrylate copolymer. materials;
  • a porous substrate made of a polymer selected from the group consisting of polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyether sulfone, polyphenylene oxide, polyphenylene sulfite and polyethylene naphthalene;
  • a porous substrate formed of a mixture of inorganic particles and a binder polymer may be used.
  • a porous coating layer including a mixture of inorganic particles and a binder polymer may be further provided on at least one surface of the porous substrate made of the above-described polymer.
  • the polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyether sulfone, polyphenylene oxide, polyphenylene sulfide It is preferable to use a separator made of a non-woven material corresponding to a porous substrate made of a polymer selected from the group consisting of pits and polyethylene naphthalene.
  • the method of manufacturing a flexible secondary battery according to an aspect of the present invention includes: (S1) an internal electrode, a separation layer preventing a short circuit of the electrode formed surrounding the internal electrode, and an external electrode formed surrounding the outer surface of the separation layer. Preparing an electrode assembly having a horizontal cross-section having a predetermined shape and extending in a longitudinal direction;
  • the flexible secondary battery according to an embodiment of the present invention has no wrinkle due to skin-tight packaging of the electrode assembly, thereby improving the flexibility of the battery.
  • a heat-shrinkable tube in the packaging can exhibit better battery flexibility.
  • a polypropylene film (Yulchon Chemical) was prepared as a sealant layer.
  • graphene oxide particles graphene oxide powder, Standard Graphen Co.
  • energy was added with an ultrasonic disperser to prepare a graphene oxide dispersion composition having a concentration of 1 mg / mL.
  • metal salt CuCl 2 Sigma Aldrich, CuCl 2
  • a coating was performed with a bar coating, followed by drying to prepare a graphene oxide layer.
  • the prepared graphene oxide layer was immersed in a solution of iodic acid at 90 ° C (TCI, 57% Hydriodic acid) and maintained for at least 12 hours.
  • the formed reduced graphene oxide layer was washed with distilled water and dried at room temperature.
  • the reduced graphene oxide sheet of the reduced graphene oxide layer included in the reduced graphene oxide layer had an interulator spacing of about 0.3 to 0.4 nm, and the reduced graphene oxide layer had a thickness of about 100 nm, and
  • the graphene oxide sheet constituting the layer was found to have a thickness of 1 to 4 nm.
  • the interlayer spacing of the reduced graphene oxide sheet was measured using an XRD device and calculated using the Brag equation.
  • XRD device D4 Endeavor from Bruker was used.
  • the thickness of the reduced graphene oxide layer was determined by observing the cross section of the synthesized reduced graphene oxide layer with an SEM device, and Hitachi 4800 was used as the SEM device.
  • the thickness of the reduced graphene oxide sheet was measured using an atomic force microscope (AFM) device after spin-casting the reduced graphene oxide sheet onto an SiO 2 substrate.
  • AFM atomic force microscope
  • the negative electrode slurry was coated and dried on a wire-shaped copper current collector having a diameter of 250 ⁇ m with a loading of 3.8 mAh / cm 2 to prepare a wire-type negative electrode having a negative electrode active material layer.
  • the four prepared wire-type negative electrodes were wound to produce a spring, thereby forming an internal negative electrode part of an open structure with an empty interior and a lithium ion supply core.
  • a separation layer was formed by winding a polyolefin film separator on the other side of the internal cathode.
  • LiCoO 2 as a positive electrode active material, Denka Black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder were added to N-methylpyrrolidone (NMP) as a solvent at a weight ratio of 85: 5: 15 to prepare a positive electrode active material slurry.
  • NMP N-methylpyrrolidone
  • the positive electrode active material slurry was coated on a sheet-shaped aluminum current collector and dried to form a positive electrode active material layer.
  • Conductive layer slurry was prepared by dispersing carbon black, which is a conductive material, and PVdF binder in a NMP solvent in a 1: 1 weight ratio.
  • a conductive layer slurry was applied on the positive electrode active material layer, and after placing the porous polymer nonwoven fabric substrate on the conductive layer slurry, the conductive layer slurry was dried to prepare a sheet-like external positive electrode.
  • the prepared positive electrode was prepared by designing the N / P ratio to 108% compared to the negative electrode discharge capacity (final positive electrode loading amount: 3.3 mAh / cm 2 ). After cutting the sheet-like outer anode to have a width of 2 mm, an electrode assembly was manufactured by winding around the inner cathode and the separation layer.
  • the moisture barrier film produced above encloses the outer surface of the electrode assembly manufactured as described above so that a predetermined portion overlaps, and at this time, the outer surface of the electrode assembly is in contact with the sealant layer.
  • heat shrink tube Yulchon Chemical, a modified polyvinylidene fluoride tube
  • a non-aqueous electrolyte solution (1M LiPF 6 , ethylene carbonate (EC) / propylene carbonate (PC) / diethyl carbonate (DEC)
  • EC ethylene carbonate
  • PC propylene carbonate
  • DEC diethyl carbonate
  • a water barrier film was obtained in the same manner as in Example 1, except that CuCl 2 was not added to the dispersion composition.
  • the reduced graphene oxide sheet of the reduced graphene oxide layer in the prepared moisture barrier film had an interlayer spacing of about 0.3 to 0.4 nm, and the reduced graphene oxide layer had a thickness of about 100 nm, and the graphene The oxide sheet was found to have a thickness of 1 to 4 nm.
  • PET polyethylene terephthalate
  • the packaging for the flexible secondary battery made of the polyethylene terephthalate (PET) film and the heat-shrinkable tube in the same manner as in Example 1, and the packaging for the flexible secondary battery forming a tube that surrounds the outer surface of the flexible secondary battery electrode assembly All secondary batteries were obtained.
  • PET polyethylene terephthalate
  • a moisture barrier film was prepared by applying a polypropylene film, a sealant layer, by a bar coating method to both sides of a polyethylene terephthalate (PET) film (Ramiace Co., Ltd., a laminating film).
  • PET polyethylene terephthalate
  • each of the moisture barrier films prepared in Example 1 and Comparative Examples 1 and 2 were prepared in a size of 10 x 10 cm, and after being cut, a moisture permeability tester (manufacturer: Sejin Test Technology Co., Ltd.) , Model name: SJTM-014), respectively. Then, dry nitrogen gas containing no water vapor was introduced into one side of the packaging for the flexible secondary battery, and water vapor was introduced into the other side. At this time, the two spaces into which the respective gases were introduced were separated from each other so that the gases flowing into both sides of the packaging for the flexible secondary battery did not mix. On the other hand, during the experiment, the temperature was set at 38 ° C. and the humidity was maintained at 100% RH.
  • Example 1 As a result, as shown in Table 1 below, it was confirmed that the water vapor transmission rate of the moisture barrier film of Example 1 was significantly improved compared to the packaging film for secondary batteries of Comparative Examples 1 and 2, respectively.
  • the packaging film for secondary batteries in which the reduced graphene oxide sheet constituting the reducing graphene oxide layer forms an electrostatic interaction can effectively block moisture compared to the packaging film for secondary batteries without the electrostatic interaction. I could confirm.

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Abstract

The purpose of the present invention is to improve the moisture barrier properties and flexibility of a flexible secondary battery, and provided are a flexible secondary battery packaging for encompassing the outer surface of an electrode assembly for the flexible secondary battery, and a flexible secondary battery comprising same, the flexible secondary battery packaging packaging having a pipe shape for encompassing the outer surface of an electrode assembly, and comprising: a moisture barrier film comprising a reduced graphene oxide (rGO) layer, which comprises a plurality of rGO sheets, and a sealant layer located on one side and/or the other side of the rGO; and a polymer heat shrinking tube for encompassing the outermost part of the moisture barrier film, wherein electrostatic interactions occur between adjacent rGO sheets from among the plurality of rGO sheets of the rGO layer.

Description

플렉서블 이차전지용 패키징 및 이를 포함하는 플렉서블 이차전지 Packaging for flexible secondary battery and flexible secondary battery including the same
본 출원은 2018년 10월 19일에 출원된 한국특허출원 제10-2018-0125542호에 기초한 우선권을 주장한다. This application claims priority based on Korean Patent Application No. 10-2018-0125542 filed on October 19, 2018.
본 발명은 플렉서블 이차전지용 패키징 및 이를 포함하는 플렉서블 이차전지에 관한 것이다.The present invention relates to a flexible secondary battery packaging and a flexible secondary battery comprising the same.
이차전지는 외부의 전기 에너지를 화학 에너지의 형태로 바꾸어 저장해 두었다가 필요할 때에 전기를 만들어 내는 장치를 말한다. 여러 번 충전할 수 있다는 뜻으로 "충전식 전지"(rechargeable battery)라는 명칭도 쓰인다. 흔히 쓰이는 이차전지로는 납 축전지, 니켈 카드뮴 전지(NiCd), 니켈 수소 축전지(NiMH), 리튬 이온 전지(Li-ion), 리튬 이온 폴리머 전지(Li-ion polymer)가 있다. 이차전지는 한 번 쓰고 버리는 일차 전지에 비해 경제적인 이점과 환경적인 이점을 모두 제공한다.A secondary battery is a device that converts and stores external electrical energy into chemical energy and then generates electricity when needed. The name "rechargeable battery" is also used to mean that it can be charged multiple times. Commonly used secondary batteries include lead-acid batteries, nickel-cadmium batteries (NiCd), nickel-metal hydride batteries (NiMH), lithium-ion batteries (Li-ion), and lithium-ion polymer batteries (Li-ion polymer). Secondary batteries offer both economic and environmental advantages over primary batteries that are used once and discarded.
이차전지는 현재 낮은 전력을 사용하는 곳에 쓰인다. 이를테면 자동차의 시동을 돕는 기기, 휴대용 장치, 도구, 무정전 전원 장치를 들 수 있다. 최근 무선통신 기술의 발전은 휴대용 장치의 대중화를 주도하고 있으며, 종래의 많은 종류의 장치들을 무선화하는 경향도 있어, 이차전지에 대한 수요가 폭발하고 있다. 또한, 환경오염 등의 방지 측면에서 하이브리드 자동차, 전기 자동차가 실용화되고 있는데, 이들 차세대 자동차들은 이차전지를 사용하여 값과 무게를 줄이고 수명을 늘리는 기술을 채용하고 있다.Secondary batteries are currently used where low power is used. For example, there are devices, portable devices, tools, and uninterruptible power supplies to help start the car. Recently, the development of wireless communication technology has led to the popularization of portable devices, and there is also a tendency to wirelessize many types of conventional devices, and the demand for secondary batteries is exploding. In addition, hybrid vehicles and electric vehicles have been put into practical use in terms of prevention of environmental pollution, and these next-generation vehicles employ technology that reduces the value, weight, and extends the life span by using a secondary battery.
이차전지 종류로 원통형, 각형, 파우치형의 이차전지가 알려져 있으며, 최근에는 단면적 직경에 대해 길이의 비가 매우 큰 전지인 케이블형 이차전지를 비롯하여, 유연성을 특징으로 하는 플렉서블(flexible) 이차전지가 제안되었다.Cylindrical, prismatic, and pouch-type secondary batteries are known as secondary battery types, and recently, flexible secondary batteries featuring flexibility, including a cable-type secondary battery, which is a battery having a very large ratio to the cross-sectional diameter, are proposed. Became.
도 1은 일반적인 플렉서블 이차전지의 일 실시양태의 구조를 도시한 도면이다. 도 1에 도시된 바와 같이, 플렉서블 이차전지(50)는, 코일 형태로 권취되어 구비되는 음극(10)과, 원통형으로 구비되고 일측에 음극(10)이 마련되어 음극(10)의 타측면을 감싸는 세퍼레이터(20)와, 세퍼레이터(20)의 타측면에 마련되는 양극(30)과, 원통형으로 구비되고 일측에 양극(30)이 마련되는 패키징(40)을 포함한다. 즉, 코일 형상으로 구비되는 음극(10)을 중심으로 그 타측면에 세퍼레이터(20), 양극(30), 패키징(40)을 순차적으로 권취하여 플렉서블 이차전지(50)를 마련한다. 이와 같이, 플렉서블 이차전지(50)는 케이블 형상으로 구비되어 휘어질 수 있도록 마련된다.1 is a view showing the structure of an embodiment of a general flexible secondary battery. As illustrated in FIG. 1, the flexible secondary battery 50 is provided with a negative electrode 10 wound around a coil and provided in a cylindrical shape, and provided with a negative electrode 10 on one side to surround the other side of the negative electrode 10. It includes a separator 20, an anode 30 provided on the other side of the separator 20, and a packaging 40 provided in a cylindrical shape and provided with an anode 30 on one side. That is, the flexible secondary battery 50 is prepared by sequentially winding the separator 20, the anode 30, and the packaging 40 on the other side of the cathode 10 provided in a coil shape. In this way, the flexible secondary battery 50 is provided in a cable shape so that it can be bent.
도 2는 라미네이트 필름 및 열수축 튜브를 포함하는 플렉서블 이차전지용 패키징으로, 상기 플렉서블 이차전지용 패키징에 열을 가하기 전의 상태이다. 도 2에 따르면, 소정의 지지층(1) 및 상기 지지층(1)의 양쪽면에 실란트 폴리머층(2)을 포함하는 라미네이트 필름(50)이 전극조립체의 외면을 감싸면서 소정 부분이 겹치도록 되어있으며, 그 외곽에 열수축 튜브(60)가 존재하게 된다. 이 후에 열을 가하게 되면, 열수축 튜브는 수축하여 전극조립체를 감싸는 라미네이트 필름 및 열수축 튜브 사이를 빈틈없이 타이트하게 패키징한다.2 is a packaging for a flexible secondary battery including a laminate film and a heat shrink tube, a state before applying heat to the packaging for the flexible secondary battery. According to FIG. 2, a laminate film 50 including a sealant polymer layer 2 on both sides of a predetermined support layer 1 and the support layer 1 surrounds the outer surface of the electrode assembly so that a predetermined portion overlaps. , The outer heat shrink tube 60 is present. When heat is applied after this, the heat-shrinkable tube contracts tightly and tightly wraps the laminate film surrounding the electrode assembly and the heat-shrinkable tube.
상기 열수축 튜브는 일반적으로 폴리머 재료를 주성분으로 하여 제조된다. 이들 폴리머는 그 구조적 특징으로 인해 다공성으로 제조되기 때문에, 수분, 공기 등이 전지 내부로 쉽게 유입되는 문제가 있다. 이러한 수분의 전지내 유입은 LiPF 6를 리튬 염으로 사용하는 전해액에 있어서 수분과의 반응에 의해 전지의 성능을 열화시키는 주된 원인이 된다. The heat-shrinkable tube is generally made of a polymer material as a main component. Since these polymers are made porous due to their structural characteristics, there is a problem that moisture, air, and the like are easily introduced into the battery. The inflow of moisture into the battery is a major cause of deterioration of the performance of the battery by reaction with moisture in the electrolyte solution using LiPF 6 as a lithium salt.
따라서, 본 발명에서 해결하고자 하는 일 과제는 플렉서블 이차전지 패키징에 열수축 튜브가 포함되는 경우에, 상기 열수축 튜브의 수분 차단 특성을 개선하는 것이다. Therefore, one problem to be solved in the present invention is to improve the moisture barrier properties of the heat-shrinkable tube when the heat-shrinkable tube is included in the flexible secondary battery packaging.
본 발명에서 해결하고자 하는 다른 과제는 상기 열수축 튜브의 수분 차단 특성을 개선하는 동시에 플렉서블 이차전지의 유연성이 확보되도록 하는 것이다. Another problem to be solved in the present invention is to improve the moisture barrier properties of the heat-shrinkable tube while ensuring flexibility of the flexible secondary battery.
또한, 본 발명에서 해결하고자 하는 또 다른 과제는 열수축 튜브의 수분 차단 특성이 개선된 플렉서블 이차전지를 제공하는 것이다.In addition, another problem to be solved in the present invention is to provide a flexible secondary battery with improved moisture barrier properties of the heat shrink tube.
본 발명의 제1 양태에서는, 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징에 있어서, 상기 플렉서블 이차전지용 패키징은 상기 전극조립체의 외면을 둘러싸는 관 형태이고, 상기 플렉서블 이차전지용 패키징은, 복수 개의 환원 그래핀 옥사이드 시트를 포함하는 환원 그래핀 옥사이드(reduced Graphene Oxide (rGO))층과 상기 환원 그래핀 옥사이드의 일측 및 타측 중 어느 하나 이상에 위치하는 실란트층을 포함하는 수분 차단 필름; 및 상기 수분 차단 필름의 최외측을 둘러싸는 고분자 열수축 튜브;를 포함하고, 상기 환원 그래핀 옥사이드층에서 상기 복수 개의 환원 그래핀 옥사이드 시트는 서로 인접한 환원 그래핀 옥사이드 시트 사이에 정전기적 상호작용을 형성하고 있는 것을 특징으로 하는, 플렉서블 이차전지용 패키징이 제공된다.In the first aspect of the present invention, in the packaging for a flexible secondary battery surrounding the outer surface of the flexible secondary battery electrode assembly, the packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly, the packaging for the flexible secondary battery, A moisture barrier film comprising a reduced graphene oxide (rGO) layer comprising a plurality of reduced graphene oxide sheets and a sealant layer located on at least one of the one side and the other side of the reduced graphene oxide; And a polymer heat shrink tube surrounding the outermost side of the moisture barrier film, wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer form electrostatic interactions between the reduced graphene oxide sheets adjacent to each other. Packaging for a flexible secondary battery is provided, which is characterized in that.
본 발명의 제2 양태에서는, 상기 제1 양태에서 상기 환원 그래핀 옥사이드 시트는 환원 그래핀 옥사이드 입자 1 내지 3개의 층구조를 갖는 것을 특징으로 하는 플렉서블 이차전지용 패키징이 제공된다.In a second aspect of the present invention, in the first aspect, the reduced graphene oxide sheet is provided with a flexible secondary battery packaging, characterized in that it has a layer structure of 1 to 3 reduced graphene oxide particles.
본 발명의 제3 양태에서는, 상기 제1 양태 또는 제2 양태에서 상기 환원 그래핀 옥사이드 시트는 0.1 내지 10 ㎛ 범위의 두께를 갖는 것을 특징으로 하는 플렉서블 이차전지용 패키징이 제공된다.In the third aspect of the present invention, in the first aspect or the second aspect, the reduced graphene oxide sheet is provided with a packaging for a flexible secondary battery, characterized in that it has a thickness in the range of 0.1 to 10 μm.
본 발명의 제4 양태에서는, 상기 제1 양태 내지 제3 양태 중 어느 하나의 양태에서 상기 환원 그래핀 옥사이드 시트는 Li +, K +, Ag +, Mg 2 +, Ca 2 +, Cu 2 +, Pb 2 +, Co 2+, Al 3 +, Cr 3 +, Fe 3 + 또는 이들 2 이상에 의해 인접 환원 그래핀 옥사이드 시트와 정전기적 상호작용을 형성하는 것을 특징으로 하는 플렉서블 이차전지용 패키징이 제공된다.In a fourth aspect of the present invention, the reduced graphene oxide sheet in any one of the first to third aspects is Li + , K + , Ag + , Mg 2 + , Ca 2 + , Cu 2 + , Pb 2 + , Co 2+ , Al 3 + , Cr 3 + , Fe 3 + or two or more of these are provided for packaging a flexible secondary battery, characterized in that it forms an electrostatic interaction with the adjacent reduced graphene oxide sheet. .
본 발명의 제5 양태에서는, 상기 제1 양태 내지 제4 양태 중 어느 하나의 양태에서 상기 수분 차단 필름은, 상기 환원 그래핀 옥사이드의 일측에 위치하는 실란트층을 포함하고, 상기 환원 그래핀 옥사이드층의 타측에 위치하는 기계적 지지층을 더 포함하고, 양 단부가 겹쳐진 형태로 상기 전극조립체의 외면을 둘러싸는 관형태를 이루고, 상기 수분 차단 필름의 서로 겹쳐진 양 단부의 대향하는 실란트층이 열압착되어 실링부를 이루고, 상기 실링부가 상기 수분 차단 필름의 둘레를 따라 폴딩된 날개부를 형성하는 것을 특징으로 하는 플렉서블 이차전지용 패키징이 제공된다.In a fifth aspect of the present invention, in any one of the first to fourth aspects, the moisture barrier film includes a sealant layer located on one side of the reduced graphene oxide, and the reduced graphene oxide layer Further comprising a mechanical support layer located on the other side of the, both ends are formed in a tubular shape surrounding the outer surface of the electrode assembly in the form of overlapping, the opposite sealant layers of the water barrier film overlapping each other are heat-pressed and sealed Packaging is provided for a flexible secondary battery, characterized in that the sealing portion forms a folded wing portion along the periphery of the moisture barrier film.
본 발명의 제6 양태에서는, 상기 제1 양태 내지 제5 양태 중 어느 하나의 양태에서 상기 기계적 지지층과 상기 환원 그래핀 옥사이드층 사이, 및 상기 환원 그래핀 옥사이드층과 상기 실란트층 사이 중 적어도 하나 이상에 접착층을 더 포함하는 플렉서블 이차전지용 패키징이 제공된다.In a sixth aspect of the present invention, at least one of the mechanical support layer and the reduced graphene oxide layer, and between the reduced graphene oxide layer and the sealant layer in any one of the first to fifth aspects Packaging for a flexible secondary battery further comprising an adhesive layer is provided.
본 발명의 제7 양태에서는, 상기 제1 양태 내지 제6 양태 중 어느 하나의 양태에서 상기 수분 차단 필름은, 상기 환원 그래핀 옥사이드층의 일측 및 타측 모두에 위치하는 2개의 실란트층을 포함하고, 상기 2개의 실란트층은 상기 환원 그래핀 옥사이드층의 일측에 위치하는 제1 실란트층과 상기 환원 그래핀 옥사이드층의 타측에 위치하는 제2 실란트층이고, 상기 수분 차단 필름의 한쪽 단부 일면의 제1 실란트층과 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹쳐서 접착되어 있는 플렉서블 이차전지용 패키징이 제공된다.In a seventh aspect of the present invention, in any one of the first to sixth aspects, the moisture barrier film includes two sealant layers located on one side and the other side of the reduced graphene oxide layer, The two sealant layers are a first sealant layer located on one side of the reduced graphene oxide layer and a second sealant layer located on the other side of the reduced graphene oxide layer, and a first of one end surface of the moisture barrier film A packaging for a flexible secondary battery is provided in which a sealant layer and a second sealant layer on the other end of the other end overlap and adhere to each other.
본 발명의 제8 양태에서는, 상기 제1 양태 내지 제7 양태 중 어느 하나의 양태에서 상기 환원 그래핀 옥사이드층과 상기 제2 실란트층 사이에 기계적 지지층을 더 포함하는 플렉서블 이차전지용 패키징이 제공된다.In an eighth aspect of the present invention, in one of the first to seventh aspects, packaging for a flexible secondary battery is further provided, further comprising a mechanical support layer between the reduced graphene oxide layer and the second sealant layer.
본 발명의 제9 양태에서는, 상기 제7 양태에서 상기 환원 그래핀 옥사이드층과 상기 제1 실란트층 사이, 상기 환원 그래핀 옥사이드층과 상기 제2 실란트층 사이, 상기 기계적 지지층과 상기 제2 실란트층 사이 중 적어도 하나 이상에 접착층을 더 포함하는 플렉서블 이차전지용 패키징이 제공된다.In the ninth aspect of the present invention, in the seventh aspect, between the reduced graphene oxide layer and the first sealant layer, between the reduced graphene oxide layer and the second sealant layer, the mechanical support layer and the second sealant layer Packaging for a flexible secondary battery further comprising an adhesive layer on at least one of the gaps is provided.
본 발명의 제10 양태에서는, 상기 제1 양태 내지 제9 양태 중 어느 하나의 양태에서 상기 환원 그래핀 옥사이드층이 20 nm 내지 30 ㎛ 범위의 두께를 가지는 것인 플렉서블 이차전지용 패키징이 제공된다.In the tenth aspect of the present invention, the packaging for a flexible secondary battery is provided in which the reduced graphene oxide layer has a thickness in the range of 20 nm to 30 μm in any one of the first to ninth aspects.
본 발명의 제11 양태에서는, 상기 제1 양태 내지 제10 양태 중 어느 하나의 양태에서 상기 환원 그래핀 옥사이드층이 0.3 nm 내지 5.0 nm 범위의 인터레이어(interlayer) 간격을 갖는 것인 플렉서블 이차전지용 패키징이 제공된다.In the eleventh aspect of the present invention, the packaging of a flexible secondary battery in which the reduced graphene oxide layer has an interlayer spacing in the range of 0.3 nm to 5.0 nm in any one of the first to tenth aspects. Is provided.
본 발명의 제12 양태에서는, 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징의 제조방법으로서, In a twelfth aspect of the present invention, a method of manufacturing a packaging for a flexible secondary battery surrounding an outer surface of the flexible secondary battery electrode assembly,
실란트층을 준비하는 단계;Preparing a sealant layer;
그래핀 옥사이드(Graphene Oxide (GO)) 입자와 금속염이 분산되어 있는 분산조성물을 상기 실란트층 상에 코팅 및 건조하여, 환원된 그래핀 옥사이드 층(reduced Graphene Oxide (rGO))을 형성시켜서, 상기 실란트층의 일면에 환원된 그래핀 옥사이드층이 형성되어 있는 수분 차단 필름을 형성하는 단계;Graphene oxide (Graphene Oxide (GO)) coated with a dispersion composition in which particles and metal salts are dispersed and dried on the sealant layer to form a reduced graphene oxide (rGO), the sealant Forming a moisture barrier film having a reduced graphene oxide layer formed on one surface of the layer;
상기 수분 차단 필름으로 상기 플렉서블 이차전지 전극조립체의 외면을 감싸도록 하는 단계; 및 Covering the outer surface of the flexible secondary battery electrode assembly with the moisture barrier film; And
상기 수분 차단 필름에 의해 외면이 감싸진 전극조립체의 외곽에 열수축 튜브가 존재하도록 한 후에 상기 열수축 튜브를 수축시키는 단계;Shrinking the heat-shrinkable tube after allowing the heat-shrinkable tube to exist on the outside of the electrode assembly whose outer surface is covered by the moisture barrier film;
를 포함하는 것을 특징으로 하는 제 1 양태에 기재된 플렉서블 이차전지용 패키징의 제조방법이 제공된다.A method of manufacturing a packaging for a flexible secondary battery according to the first aspect, comprising a.
본 발명의 제13 양태에서는, 상기 제12 양태에서 상기 그래핀 옥사이드층이 요오드산 또는 비타민 C에 의해 환원되는 것인 플렉서블 이차전지용 패키징의 제조방법이 제공된다.In a thirteenth aspect of the present invention, a method for manufacturing a flexible secondary battery packaging method in which the graphene oxide layer is reduced by iodic acid or vitamin C in the twelfth aspect is provided.
본 발명의 제14 양태에서는, 상기 제12 양태에서 상기 수분 차단 필름은, 상기 환원 그래핀 옥사이드층의 일측 및 타측 모두에 위치하는 2개의 실란트층을 포함하고, 상기 2개의 실란트층은 상기 환원 그래핀 옥사이드층의 일측에 위치하는 제1 실란트층과 상기 환원 그래핀 옥사이드층의 타측에 위치하는 제2 실란트층이고, 상기 수분 차단 필름의 한쪽 단부 일면의 제1 실란트층과 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹쳐서 접착되어 있는 플렉서블 이차전지용 패키징의 제조방법이 제공된다.In a fourteenth aspect of the present invention, in the twelfth aspect, the moisture barrier film includes two sealant layers located on one side and the other side of the reduced graphene oxide layer, and the two sealant layers are the reduced graphene A first sealant layer located on one side of the pin oxide layer and a second sealant layer located on the other side of the reduced graphene oxide layer, and a first sealant layer on one end of the moisture barrier film and a second sealant on the other end A method of manufacturing a flexible secondary battery packaging in which a sealant layer is adhered to each other by overlapping a predetermined portion is provided.
본 발명의 제15 양태에서는, 본 발명의 제13 양태에서는, 전극조립체; 상기 전극조립체의 외면을 둘러싸고 있는 제1항의 플렉서블 이차전지용 패키징;을 포함하는 플렉서블 이차전지가 제공된다.In the fifteenth aspect of the invention, in the thirteenth aspect of the invention, the electrode assembly; A flexible secondary battery including; packaging for the flexible secondary battery of claim 1 surrounding the outer surface of the electrode assembly is provided.
본 발명에 따르는 플렉서블 이차전지용 패키징은 전극조립체와 열수축 튜브 사이에 수분 차단 필름이 존재하여, 수분 및/또는 가스가 이차전지 내로 유입되는 현상이 방지될 수 있다.In the packaging for a flexible secondary battery according to the present invention, a moisture barrier film is present between the electrode assembly and the heat shrink tube, so that moisture and / or gas flowing into the secondary battery can be prevented.
특히, 본 발명의 플렉서블 이차전지용 패키징은 상기 수분 차단 필름에 환원 그래핀 옥사이드층이 포함된다. 그래핀 옥사이드층의 경우에 그래핀 옥사이드 인터레이어 사이에 수 개의 물 단분자층(water monolayer)이 존재하여 수분 및/또는 가스 분자의 차단이 이루어질 수 없는 것과 대조적으로, 본 발명에 따른 환원 그래핀 옥사이드층은, 상기 환원 그래핀 옥사이드층을 구성하는 환원 그래핀 옥사이드 시트간에 정전기적 상호작용이 형성되어 있어 수분 및/또는 가스가 유입될 수 있는 경로가 매우 효과적으로 차단되는 효과를 갖는다. In particular, the packaging for a flexible secondary battery of the present invention includes a reduced graphene oxide layer in the moisture barrier film. In the case of the graphene oxide layer, in contrast to the fact that several water monolayers exist between the graphene oxide interlayers, such that moisture and / or gas molecules cannot be blocked, the reduced graphene oxide layer according to the present invention Silver, an electrostatic interaction is formed between the reduced graphene oxide sheets constituting the reduced graphene oxide layer, thereby effectively blocking a path through which moisture and / or gas can be introduced.
또한, 본 발명의 플렉서블 이차전지용 패키징에는 알루미늄과 같은 금속층이 사용되지 않으므로, 플렉서블 이차전지용 패키징 소재 자체가 유연성을 가질 수 있고, 따라서 플렉서블 이차전지가 구부러지는 경우에 발생하는 스트레스가 완화될 수 있다.In addition, since the metal layer such as aluminum is not used in the packaging for the flexible secondary battery of the present invention, the packaging material for the flexible secondary battery itself may have flexibility, and thus stress generated when the flexible secondary battery is bent can be alleviated.
도 1은 일반적인 플렉서블 이차전지의 일 실시양태의 구조를 도시한 도면이다.1 is a view showing the structure of an embodiment of a general flexible secondary battery.
도 2는 열수축 튜브에 삽입되어 있되 열처리되기 전인 일반적인 플렉서블 이차전지의 일 실시양태를 개략적으로 나타낸 단면도이다.2 is a cross-sectional view schematically showing an embodiment of a general flexible secondary battery inserted into a heat-shrinkable tube but before being heat-treated.
도 3은 본 발명의 일 실시양태에 따른 수분 차단 필름을 개략적으로 도시한 단면도이다.3 is a cross-sectional view schematically showing a moisture barrier film according to an embodiment of the present invention.
도 4는 본 발명의 일 실시양태에 따른 수분 차단 필름을 개략적으로 도시한 단면도이다.4 is a cross-sectional view schematically showing a moisture barrier film according to an embodiment of the present invention.
도 5는 본 발명의 일 실시양태에 따른 수분 차단 필름을 개략적으로 도시한 단면도이다.5 is a cross-sectional view schematically showing a moisture barrier film according to an embodiment of the present invention.
도 6은 본 발명의 일 실시양태에 따른 환원 그래핀 옥사이드층을 개략적으로 도시한 내부 단면도이다.6 is an internal cross-sectional view schematically showing a reduced graphene oxide layer according to an embodiment of the present invention.
도 7은 본 발명의 일 실시양태에 따라 전극조립체에 수분 차단 필름 및 열수축성 튜브가 적용된 일 실시양태를 개략적으로 나타낸 단면도이다.7 is a cross-sectional view schematically showing an embodiment in which a moisture barrier film and a heat shrinkable tube are applied to an electrode assembly according to an embodiment of the present invention.
도 8은 본 발명의 일 실시양태에 따라 전극조립체에 수분 차단 필름 및 열수축성 튜브가 적용된 일 실시양태를 개략적으로 나타낸 단면도이다.8 is a cross-sectional view schematically showing an embodiment in which a moisture barrier film and a heat shrinkable tube are applied to an electrode assembly according to an embodiment of the present invention.
도 9는 실시예 3 및 비교예 4에서 제작된 이차전지의 사이클 성능을 나타낸 그래프이다.9 is a graph showing the cycle performance of the secondary battery produced in Example 3 and Comparative Example 4.
이하, 본 발명을 상세히 설명하기로 한다. 본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 아니되며, 발명자는 그 자신의 발명을 가장 최선의 방법으로 설명하기 위해 용어의 개념을 적절하게 정의할 수 있다는 원칙에 입각하여 본 발명의 기술적 사상에 부합하는 의미와 개념으로 해석되어야만 한다. 따라서, 본 명세서에 기재된 실시예와 도면에 기재된 구성은 가장 바람직한 일 실시예에 불과할 뿐이고, 본 발명의 기술적 사상을 모두 대변하는 것은 아니므로, 본 출원시점에 있어서 이들을 대체할 수 있는 다양한 균등물과 변형예들이 있을 수 있음을 이해하여야 한다.Hereinafter, the present invention will be described in detail. The terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or lexical meanings, and the inventor can appropriately define the concept of terms in order to best describe his or her invention. Based on the principle that it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention. Therefore, the embodiments described in the present specification and the configuration described in the drawings are only the most preferred embodiments, and do not represent all of the technical spirit of the present invention, and various equivalents that can replace them at the time of this application It should be understood that there may be variations.
본원 명세서 전체에서, 어떤 부분이 다른 부분과 "연결"되어 있다고 할 때, 이는 "직접적으로 연결"되어 있는 경우뿐 아니라, 그 중간에 다른 부재를 사이에 두고 "전기적으로 연결"되어 있는 경우도 포함한다.Throughout this specification, when a part is "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another member in between. do.
본원 명세서 전체에서, 어떤 부재가 다른 부재 "타측에" 위치하고 있다고 할 때, 이는 어떤 부재가 다른 부재의 일 표면에 접해있는 경우뿐만 아니라, 상기 두 부재 사이에 또 다른 부재가 존재하는 경우도 포함하는 의미이다.Throughout this specification, when a member is said to be located “on the other side” of another member, this includes not only the case where one member abuts one surface of the other member, but also the case where another member exists between the two members Meaning.
본원 명세서 전체에서, 어떤 부분이 어떤 구성 요소를 "포함"한다고 할 때, 이는 특별히 반대되는 기재가 없는 한 다른 구성 요소를 제외하는 것이 아니라 다른 구성 요소를 더 포함할 수 있는 것을 의미한다. 본원 명세서 전체에서 사용되는 정도의 용어 "약"은 언급된 의미에 고유한 제조 및 물질 허용오차가 제시될 때 그 수치에서 또는 그 수치에 근접한 의미로 사용되고, 본원의 이해를 돕기 위해 정확하거나 절대적인 수치가 언급된 개시 내용을 비양심적인 침해자가 부당하게 이용하는 것을 방지하기 위해 사용된다. Throughout this specification, when a part “includes” a certain component, it means that the component may further include other components, rather than excluding other components, unless specifically stated to the contrary. As used throughout this specification, the term “about” is used in the sense of or close to the numerical value when manufacturing and material tolerances unique to the stated meaning are given, and is an accurate or absolute numerical value to aid understanding of the present application. Is used to prevent the unfair exploitation of unconscionable intruders by the disclosures mentioned.
본원 명세서 전체에서, "A 및/또는 B"의 기재는, "A, 또는 B, 또는, A 및 B"를 의미한다.Throughout this specification, the description of “A and / or B” means “A, or B, or A and B”.
본원 명세서 전체에서, "그래핀"이라는 용어는 복수개의 탄소 원자들이 서로 공유 결합으로 연결되어 폴리시클릭 방향족 분자를 형성한 것을 의미하는 것으로서, 상기 공유 결합으로 연결된 탄소 원자들은 기본 반복 단위로서 6 원환을 형성하나, 5 원환 및/또는 7 원환을 더 포함하는 것도 가능하다. 따라서, 상기 그래핀이 형성하는 시트는 서로 공유 결합된 탄소 원자들의 단일층으로서 보일 수 있으나, 이에 제한되지 않을 수 있다. 상기 그래핀이 형성하는 시트는 다양한 구조를 가질 수 있으며, 이와 같은 구조는 그래핀 내에 포함될 수 있는 5 원환 및/또는 7 원환의 함량에 따라 달라질 수 있다. 또한, 상기 그래핀이 형성하는 시트가 단일층으로 이루어진 경우, 이들이 서로 적층되어 복수층을 형성할 수 있으며, 상기 그래핀 시트의 측면 말단부는 수소 원자로 포화될 수 있으나, 이에 제한되지 않을 수 있다.Throughout the present specification, the term "graphene" means that a plurality of carbon atoms are covalently linked to each other to form a polycyclic aromatic molecule, wherein the covalently linked carbon atoms form a six-membered ring as a basic repeating unit. It forms, but it is also possible to further include a 5-membered ring and / or a 7-membered ring. Therefore, the sheet formed by the graphene may be seen as a single layer of carbon atoms covalently bonded to each other, but may not be limited thereto. The sheet formed by the graphene may have various structures, and such a structure may vary depending on the content of the 5-membered ring and / or 7-membered ring that may be included in the graphene. In addition, when the sheet formed by the graphene is composed of a single layer, they may be stacked with each other to form a plurality of layers, and the side ends of the graphene sheet may be saturated with hydrogen atoms, but may not be limited thereto.
본원 명세서 전체에서, "그래핀 옥사이드"라는 용어는 graphene oxide라고도 불리우고, "GO"로 약칭될 수 있다. 단일층 그래핀 상에 카르복실기, 히드록시기, 또는 에폭시기 등의 산소를 함유하는 작용기가 결합된 구조를 포함할 수 있으나, 이에 제한되지 않을 수 있다.Throughout this specification, the term "graphene oxide" is also called graphene oxide and may be abbreviated as "GO". The monolayer graphene may include a structure in which a functional group containing oxygen, such as a carboxyl group, a hydroxy group, or an epoxy group, is combined, but may not be limited thereto.
본원 명세서 전체에서, "환원 그래핀 옥사이드"라는 용어는 환원 과정을 거쳐 산소 비율이 줄어든 그래핀 옥사이드를 의미하는 것으로서, "rGO"로 약칭될 수 있으나, 이에 제한되지 않을 수 있다. 비제한적인 예에서, 상기 환원 그래핀 옥사이드에 포함된 산소 함량은 탄소 100 원자수% 대비 0.01 내지 30 원자수% (at.%)의 산소를 포함할 수 있으나, 이에 한정되는 것은 아니다. Throughout the present specification, the term “reduced graphene oxide” refers to graphene oxide having a reduced oxygen ratio through a reduction process, and may be abbreviated as “rGO”, but may not be limited thereto. In a non-limiting example, the oxygen content included in the reduced graphene oxide may include 0.01 to 30 atomic% (at.%) Of oxygen relative to 100% of carbon atoms, but is not limited thereto.
본원 명세서에서, 환원 그래핀 옥사이드 시트의 인터레이어 간격은 XRD 장치를 사용하여 측정하고 Brag equation 으로 계산하여 산출하할 수 있고, 상기 XRD 장치로는 Bruker 사의 D4 Endeavor를 사용할 수 있다.In the present specification, the interlayer spacing of the reduced graphene oxide sheet may be measured using an XRD device and calculated by calculating the Brag equation, and the XRD device may use Bruker's D4 Endeavor.
본원 명세서에서, 환원 그래핀 옥사이드층의 두께는, 합성된 환원 그래핀 옥사이드층의 단면을 SEM 장치로 관찰하여 결정할 수 있고, 상기 SEM 장치로는 Hitachi 4800을 사용할 수 있다.In the present specification, the thickness of the reduced graphene oxide layer may be determined by observing the cross section of the synthesized reduced graphene oxide layer using an SEM device, and Hitachi 4800 may be used as the SEM device.
또한, 본원 명세서에서, 환원 그래핀 옥사이드 시트의 두께는, 환원 그래핀 옥사이드 시트를 SiO2 기판 위에 스핀-캐스팅(spin-casting)한 후에 Atomic Force Microscope (AFM) 장치를 사용하여 측정할 수 있고, 상기 AFM 장치로는 Park Systems사의 NX10을 사용할 수 있다.In addition, in the present specification, the thickness of the reduced graphene oxide sheet may be measured using an atomic force microscope (AFM) device after spin-casting the reduced graphene oxide sheet on an SiO 2 substrate, and the Park Systems' NX10 can be used as the AFM device.
본 발명에 따르면, 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징에 있어서, 상기 플렉서블 이차전지용 패키징은 상기 전극조립체의 외면을 둘러싸는 관 형태이고, 상기 플렉서블 이차전지용 패키징은, 복수 개의 환원 그래핀 옥사이드 시트를 포함하는 환원 그래핀 옥사이드(reduced Graphene Oxide (rGO))층과 상기 환원 그래핀 옥사이드의 일측 및 타측 중 어느 하나 이상에 위치하는 실란트층을 포함하는 수분 차단 필름; 및 상기 수분 차단 필름의 최외측을 둘러싸는 고분자 열수축 튜브;를 포함하고, 상기 환원 그래핀 옥사이드층에서 상기 복수 개의 환원 그래핀 옥사이드 시트는 서로 인접한 환원 그래핀 옥사이드 시트 사이에 정전기적 상호작용을 형성하고 있는 것을 특징으로 하는, 플렉서블 이차전지용 패키징이 제공된다.According to the present invention, in the packaging for a flexible secondary battery surrounding the outer surface of the flexible secondary battery electrode assembly, the packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly, and the packaging for the flexible secondary battery is a plurality of reduction A moisture barrier film comprising a reduced graphene oxide (rGO) layer comprising a graphene oxide sheet and a sealant layer located on at least one of the one side and the other side of the reduced graphene oxide; And a polymer heat shrink tube surrounding the outermost side of the moisture barrier film, wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer form electrostatic interactions between the reduced graphene oxide sheets adjacent to each other. Packaging for a flexible secondary battery is provided, which is characterized in that.
본 발명의 구체적인 일 실시양태에 따르면, 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징에 있어서, 상기 플렉서블 이차전지용 패키징은 상기 전극조립체의 외면을 둘러싸는 관 형태이고, 상기 플렉서블 이차전지용 패키징은, 복수 개의 환원 그래핀 옥사이드 시트를 포함하는 환원 그래핀 옥사이드(reduced Graphene Oxide (rGO))층과, 상기 환원 그래핀 옥사이드층의 일측에 위치하는 실란트층을 포함하는 수분 차단 필름; 상기 상기 수분 차단 필름의 타측에 위치하는 기계적 지지층; 및 상기 수분 차단 필름의 최외측을 둘러싸는 고분자 열수축 튜브;를 포함하고, 상기 수분 차단 필름의 서로 겹쳐진 양 단부의 대향하는 실란트층이 열압착되어 실링부를 이루고, 상기 실링부가 상기 수분 차단 필름의 둘레를 따라 폴딩된 날개부를 형성하며, 상기 환원 그래핀 옥사이드층에서 상기 복수 개의 환원 그래핀 옥사이드 시트는 서로 인접한 환원 그래핀 옥사이드 시트 사이에 정전기적 상호작용을 형성하고 있는 것을 특징으로 하는, 플렉서블 이차전지용 패키징이 제공된다.According to a specific embodiment of the present invention, in the packaging for a flexible secondary battery surrounding the outer surface of the flexible secondary battery electrode assembly, the packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly, and packaging for the flexible secondary battery A moisture barrier film comprising a reduced graphene oxide (rGO) layer comprising a plurality of reduced graphene oxide sheets and a sealant layer located on one side of the reduced graphene oxide layer; A mechanical support layer located on the other side of the moisture barrier film; And a polymer heat-shrinkable tube surrounding the outermost side of the moisture barrier film, wherein opposing sealant layers at both ends of the moisture barrier film are thermocompressed to form a sealing portion, and the sealing portion is around the moisture barrier film. Forming a folded wing portion along, wherein the plurality of reduced graphene oxide sheets in the reduced graphene oxide layer is characterized in that it forms an electrostatic interaction between the reduced graphene oxide sheet adjacent to each other, for a flexible secondary battery Packaging is provided.
본 발명의 구체적인 다른 실시양태에 따르면, 플렉서블 이차전지 전극 조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징에 있어서, 상기 플렉서블 이차전지용 패키징은, 복수 개의 환원 그래핀 옥사이드 시트를 포함하는 환원 그래핀 옥사이드(reduced Graphene Oxide (rGO))층과, 상기 환원 그래핀 옥사이드층의 일측 및 타측 모두에 위치하는 2개의 실란트층을 포함하는 수분 차단 필름; 및 상기 수분 차단 필름의 최외측을 둘러싸는 고분자 열수축 튜브;를 포함하고, 상기 2개의 실란트층은 상기 환원 그래핀 옥사이드층의 일측에 위치하는 제1 실란트층과 상기 환원 그래핀 옥사이드층의 타측에 위치하는 제2 실란트층이고, 상기 수분 차단 필름의 한쪽 단부 일면의 제1 실란트층과 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹쳐서 접착되어 있으며, 상기 환원 그래핀 옥사이드층에서 상기 복수 개의 환원 그래핀 옥사이드 시트는 서로 인접한 환원 그래핀 옥사이드 시트 사이에 정전기적 상호작용을 형성하고 있는 것을 특징으로 하는, 플렉서블 이차전지용 패키징이 제공된다.According to another specific embodiment of the present invention, in the packaging for a flexible secondary battery surrounding the outer surface of the flexible secondary battery electrode assembly, the packaging for the flexible secondary battery, the reduced graphene oxide comprising a plurality of reducing graphene oxide sheets (reduced A moisture barrier film comprising a graphene oxide (rGO) layer and two sealant layers located on one side and the other side of the reduced graphene oxide layer; And a polymer heat shrink tube surrounding the outermost side of the moisture barrier film, wherein the two sealant layers are located on one side of the reduced graphene oxide layer and on the other side of the reduced graphene oxide layer. Located second sealant layer, the first sealant layer on one end of the moisture barrier film and the second sealant layer on the other end of the other end are adhered to each other by overlapping each other, and in the reduced graphene oxide layer, the plurality of The reduced graphene oxide sheet is provided with a packaging for a flexible secondary battery, characterized in that it forms an electrostatic interaction between the reducing graphene oxide sheet adjacent to each other.
본원 명세서에서 '정전기적 상호작용'이라 할 때 상기 정전기적 상호작용은 이온결합을 포함하는 것으로 이해한다.In the present specification, the term “electrostatic interaction” is understood to include ionic bonding.
편의를 위해, 본원 명세서에서 본 발명의 플렉서블 이차전지용 패키징에서 열수축 튜브를 제외한 구성요소를 총칭하여 "수분 차단 필름"으로 지칭할 수 있다. 따라서, 본 발명의 플렉서블 이차전지용 패키징은 i) 수분 차단 필름과 ii) 열수축 튜브로 이루어진다. For convenience, in the present specification, components excluding the heat shrink tube in the packaging for the flexible secondary battery of the present invention may be collectively referred to as a “moisture barrier film”. Therefore, the packaging for the flexible secondary battery of the present invention comprises i) a moisture barrier film and ii) a heat shrink tube.
도 3을 참고하여 본 발명의 수분 차단 필름(F)의 일 실시양태를 설명하면, 기계적 지지층(110); 기계적 지지층(110)의 타측에 위치하는 접착층(120a); 상기 접착층(120a)의 타측에 위치하는 환원 그래핀 옥사이드층(130); 및 상기 환원 그래핀 옥사이드층(130)의 타측에 위치하는 접착층(120b); 및 상기 접착층(120a)의 타측에 위치하는 실란트층(150)이 순차적으로 두께 방향으로 위치하는 구조를 가질 수 있다. 상기 접착층(120a, 120b)들 중 적어도 한 층이 생략될 수 있다. 예컨대, 기계적 지지층(110)과 환원 그래핀 옥사이드층(130) 간의 친화도가 양호 내지는 우수한 경우, 기계적 지지층(110)과 환원 그래핀 옥사이드층(130) 사이의 접착층(120a)이 생략될 수 있다.Referring to Figure 3 to explain an embodiment of the moisture barrier film (F) of the present invention, the mechanical support layer 110; An adhesive layer 120a located on the other side of the mechanical support layer 110; A reduced graphene oxide layer 130 located on the other side of the adhesive layer 120a; And an adhesive layer 120b located on the other side of the reduced graphene oxide layer 130. And a sealant layer 150 positioned on the other side of the adhesive layer 120a sequentially positioned in the thickness direction. At least one layer of the adhesive layers 120a and 120b may be omitted. For example, when the affinity between the mechanical support layer 110 and the reduced graphene oxide layer 130 is good or excellent, the adhesive layer 120a between the mechanical support layer 110 and the reduced graphene oxide layer 130 may be omitted. .
도 4를 참고하여 본 발명의 수분 차단 필름(F)의 다른 실시양태를 설명하면, 도 3의 수분 차단 필름(F)의 구조에 부가하여, 기계적 지지층(210)의 타측에 위치하는 접착층(220a); 및 상기 접착층(220a)의 타측에 위치하는 제1 실란트 층(240a)이 더 포함될 수 있다. 따라서, 도 4의 수분 차단 필름(F)은 제1 실란트층(240a), 제1 접착층(220a), 기계적 지지층(210), 제2 접착층(220b), 환원 그래핀 옥사이드층(230), 제3 접착층(220c) 및 제2 실란트층(240b)이 순차적으로 두께 방향으로 위치하는 구조를 가질 수 있다. 본 실시양태의 경우에도 접착층(220a, 220b, 220c)들 중 적어도 한 층이 생략될 수 있다. 예컨대, 기계적 지지층(210)과 환원 그래핀 옥사이드층(230) 간의 친화도가 양호 내지 우수한 경우, 기계적 지지층(210)과 환원 그래핀 옥사이드층(230) 사이의 접착층(220b)이 생략될 수 있다.When explaining another embodiment of the moisture barrier film (F) of the present invention with reference to Figure 4, in addition to the structure of the moisture barrier film (F) of Figure 3, the adhesive layer (220a) located on the other side of the mechanical support layer 210 ); And a first sealant layer 240a located on the other side of the adhesive layer 220a. Accordingly, the moisture barrier film F of FIG. 4 includes a first sealant layer 240a, a first adhesive layer 220a, a mechanical support layer 210, a second adhesive layer 220b, a reduced graphene oxide layer 230, and 3 may have a structure in which the adhesive layer 220c and the second sealant layer 240b are sequentially positioned in the thickness direction. Even in the case of the present embodiment, at least one layer of the adhesive layers 220a, 220b, and 220c may be omitted. For example, when the affinity between the mechanical support layer 210 and the reduced graphene oxide layer 230 is good or excellent, the adhesive layer 220b between the mechanical support layer 210 and the reduced graphene oxide layer 230 may be omitted. .
도 5를 참고하여 본 발명의 수분 차단 필름(F)의 또 다른 실시양태를 설명하면, 본 발명의 수분 차단 필름(F)은 기계적 지지층을 포함하지 않을 수 있다. 즉, 도 5에 도시된 바와 같이, 본 발명의 수분 차단 필름(F)의 또 다른 실시양태는 제1 실란트층(340a), 상기 제1 실란트층(340a)의 타측에 위치하는 제1 접착층(320a), 상기 제1 접착층(320a)의 타측에 위치하는 환원 그래핀 옥사이드층(330), 상기 환원 그래핀 옥사이드층(330)의 타측에 위치하는 제2 접착층(320b), 및 상기 제2 접착층(320b)의 타측에 위치하는 제2 실란트층(340b)이 순차적으로 두께 방향으로 위치하는 구조를 가질 수 있다. Referring to Figure 5, another embodiment of the moisture barrier film (F) of the present invention, the moisture barrier film (F) of the present invention may not include a mechanical support layer. That is, as shown in Figure 5, another embodiment of the moisture barrier film (F) of the present invention is a first sealant layer (340a), the first adhesive layer located on the other side of the first sealant layer (340a) ( 320a), a reduced graphene oxide layer 330 located on the other side of the first adhesive layer 320a, a second adhesive layer 320b located on the other side of the reduced graphene oxide layer 330, and the second adhesive layer The second sealant layer 340b positioned on the other side of the 320b may have a structure sequentially positioned in the thickness direction.
상기 기계적 지지층은 외부 스트레스나 충격에 대하여 수분 차단 필름이 찢어지거나 손상되는 것을 방지하는 역할을 하고, 이러한 정도의 기계적 특성을 구비한 소재라면 제한없이 사용될 수 있다. The mechanical support layer serves to prevent the moisture barrier film from being torn or damaged against external stress or impact, and can be used without limitation as long as it is a material having such a mechanical property.
상기 기계적 지지층을 구성하는 물질의 비제한적인 예로, 고밀도 폴리에틸렌, 저밀도 폴리에틸렌, 선형저밀도 폴리에틸렌, 초고분자량 폴리에틸렌, 폴리프로필렌과 같은 폴리올레핀; 폴리에틸렌테레프탈레이트 (polyethyleneterephthalate), 폴리부틸렌테레프탈레이트 (polybutyleneterephthalate)와 같은 폴리에스테르 (polyester); 폴리아세탈 (polyacetal); 폴리아미드 (polyamide); 폴리카보네이트 (polycarbonate); 폴리이미드 (polyimide); 폴리에테르에테르케톤 (polyetheretherketone); 폴리에테르설폰 (polyethersulfone); 폴리페닐렌산화물 (polyphenyleneoxide); 폴리페닐렌설파이드 (polyphenylenesulfide); 및 폴리에틸렌나프탈레이트 (polyethylenenaphthalate);로 이루어진 군으로부터 선택된 1종 또는 2종 이상의 혼합물을 들 수 있으나, 이에 한정되는 것은 아니다. Non-limiting examples of materials constituting the mechanical support layer, high density polyethylene, low density polyethylene, linear low density polyethylene, ultra high molecular weight polyethylene, polyolefins such as polypropylene; Polyesters such as polyethylene terephthalate and polybutylene terephthalate; Polyacetal; Polyamide; Polycarbonate; Polyimide; Polyetheretherketone; Polyethersulfone; Polyphenylene oxide; Polyphenylenesulfide; And polyethylene naphthalate (polyethylenenaphthalate); may be mentioned one or a mixture of two or more selected from the group consisting of, but is not limited thereto.
상기 기계적 지지층은, 선택적으로, 산소 또는 질소 플라즈마 처리에 의하여 친수성 표면으로 개질될 수 있다. 상기 기계적 지지층이 소수성 표면을 갖는 경우, 기계적 지지층 표면의 소수성(hydrophobicity)과 그래핀 옥사이드의 친수성(hydrophilicity)의 차이로 인해 표면 에너지가 발생하게 되고, 그 결과 기계적 지지층의 일 표면상에 그래핀 옥사이드층의 균일한 코팅을 확보하기가 곤란할 수 있다. 이를 제어할 목적으로 소수성 표면을 갖는 기계적 지지층의 표면을 친수성으로 표면 개질(surface modification)할 수 있다. 상기 표면 개질은 UV-오존 처리, 산소 또는 질소를 이용한 플라즈마 표면 처리법, 아미노 실란과 같은 실란 커플링제를 이용한 화학적 처리, 또는 고분자나 유기 화합물을 이용한 표면 코팅 등에 의해 이루어질 수 있으나, 이에 한정되는 것은 아니다. The mechanical support layer can optionally be modified to a hydrophilic surface by oxygen or nitrogen plasma treatment. When the mechanical support layer has a hydrophobic surface, surface energy is generated due to a difference between the hydrophobicity of the surface of the mechanical support layer and the hydrophilicity of graphene oxide, and as a result, graphene oxide is formed on one surface of the mechanical support layer. It may be difficult to ensure a uniform coating of the layer. For the purpose of controlling this, the surface of a mechanical support layer having a hydrophobic surface can be surface modified with hydrophilicity. The surface modification may be performed by UV-ozone treatment, plasma surface treatment using oxygen or nitrogen, chemical treatment using a silane coupling agent such as amino silane, or surface coating using a polymer or organic compound, but is not limited thereto. .
환원 그래핀 옥사이드층이 상기 기계적 지지층의 일 표면에 직접 또는 접착층을 사이에 두고 형성될 수 있다.The reduced graphene oxide layer may be formed directly on one surface of the mechanical support layer or with an adhesive layer therebetween.
상기 환원 그래핀 옥사이드층은 본 발명에 따른 플렉서블 이차전지용 패키징이 수분 및/또는 가스의 유입을 차단하는 효과를 갖도록 하는 구성요소이다. 상기 차단 효과는 그래핀 옥사이드층의 두께 및 그래핀 옥사이드 정렬도와 같은 요인에 의해 좌우될 수 있으며, 이들은 환원 그래핀 옥사이드를 제조하는 공정 조건에 따라 결정될 수 있다. 상기 공정 조건으로는 그래핀 옥사이드의 순도, 그래핀 옥사이드 분산조성물의 농도, 코팅 시간 및 코팅 횟수, 코팅 후 용매의 증발 속도, 전단력(shear force) 유무 등이 있으나, 이에 제한되는 것은 아니다.The reduced graphene oxide layer is a component that enables the packaging for a flexible secondary battery according to the present invention to block the inflow of moisture and / or gas. The blocking effect may be influenced by factors such as the thickness of the graphene oxide layer and the degree of graphene oxide alignment, and these may be determined according to process conditions for producing reduced graphene oxide. The process conditions include, but are not limited to, the purity of the graphene oxide, the concentration of the graphene oxide dispersion composition, the coating time and the number of coatings, the evaporation rate of the solvent after coating, the presence or absence of shear force, and the like.
이에, 환원 그래핀 옥사이드층의 제조방법을 살펴보면, 상기 환원 그래핀 옥사이드층은, 그래핀 옥사이드(Graphene Oxide (GO)) 입자와 금속염이 분산되어 있는 분산조성물을 기계적 지지층의 일 표면 상에 직접 또는 접착층을 사이에 두고 코팅 및 건조하여 그래핀 옥사이드층을 형성시키고, 형성된 그래핀 옥사이드층을 환원시켜 수득될 수 있다. 또는, 수분 차단 필름에 기계적 지지층이 포함되지 않는 경우에는 그래핀 옥사이드 입자와 금속염이 분산되어 그래핀 옥사이드 분산조성물을 실란트 층의 일 표면 상에 직접 또는 접착층을 사이에 두고 코팅 및 건조하고, 환원시켜 수득될 수 있다.Thus, looking at the method of manufacturing a reduced graphene oxide layer, the reduced graphene oxide layer may directly or directly disperse a dispersion composition in which graphene oxide (GO) particles and metal salts are dispersed on one surface of a mechanical support layer. It can be obtained by coating and drying the adhesive layer therebetween to form a graphene oxide layer, and reducing the formed graphene oxide layer. Alternatively, when the mechanical barrier is not included in the moisture barrier film, the graphene oxide particles and the metal salt are dispersed to coat and dry the graphene oxide dispersion composition directly on one surface of the sealant layer or with an adhesive layer therebetween and reduce it. Can be obtained.
도 6을 참고하여 본 발명에 따른 환원 그래핀 옥사이드층(230)의 개략적으로 도시된 단면도를 살펴보면, 환원 그래핀 옥사이드 입자(2310), 예컨대 환원 그래핀 옥사이드 평면입자가 복수개 적층되어 환원 그래핀 옥사이드 시트(2320)를 형성하고, 이와 같이 형성된 환원 그래핀 옥사이드 시트(2320) 복수개가 환원 그래핀 옥사이드층을 형성하며, 이 때, 상기 환원 그래핀 옥사이드 시트(2320)는, 금속 양이온에 의해, 인접한 환원 그래핀 옥사이드 시트와 정전기적 상호작용(2320)을 형성한다.Referring to Figure 6 to look at the schematic cross-sectional view of the reduced graphene oxide layer 230 according to the present invention, a plurality of reduced graphene oxide particles 2310, for example, reduced graphene oxide flat particles are stacked to reduce graphene oxide A sheet 2320 is formed, and a plurality of reduced graphene oxide sheets 2320 formed as described above form a reduced graphene oxide layer. At this time, the reduced graphene oxide sheet 2320 is adjacent to a metal cation. It forms an electrostatic interaction 2320 with the reduced graphene oxide sheet.
보다 구체적으로, 금속 양이온은 환원된 그래핀 옥사이드 입자의 가장자리(edge) 부분에 존재하는 산소 기능기들과 정전기적 상호작용을 한다. 산소 기능기는 (-) 전하, 금속 양이온은 (+) 전하를 가지므로, 2개 또는 그 이상의 환원된 그래핀 옥사이드 입자 사이에서 정전기적 상호작용으로 인한 충분한 인력을 가지려면 2+ 이상의 산화수를 갖는 양이온이 바람직하다. 또한, 상기 금속 양이온과 환원된 그래핀 옥사이드 입자 간의 인력은 환원된 그래핀 옥사이드 입자 가장자리에서 일어나는 상호작용이므로, 기저면(basal plane) 부분에 있는 환원된 그래핀 옥사이드 시트 간의 간격은 유지된다. More specifically, the metal cation interacts electrostatically with oxygen functional groups present at the edge portion of the reduced graphene oxide particles. Since the oxygen functional group has a (-) charge and a metal cation has a (+) charge, a cation having an oxidation number of 2+ or more to have sufficient attraction due to electrostatic interaction between two or more reduced graphene oxide particles This is preferred. In addition, since the attraction force between the metal cation and the reduced graphene oxide particles is an interaction occurring at the edge of the reduced graphene oxide particles, the spacing between the reduced graphene oxide sheets in the basal plane portion is maintained.
본 발명의 구체적인 일 실시양태에 따르면, 상기 환원 그래핀 옥사이드 시트는 환원 그래핀 옥사이드 입자, 예컨대, 환원 그래핀 옥사이드 판상입자 1 내지 3개의 층구조 형태일 수 있다. 이러한 환원 그래핀 옥사이드의 층구조는 그래핀 옥사이드의 환원반응 이전에 이루어져야 한다. 일반적으로 그래핀 옥사이드는 흑연을 산화시킨 후에 초음파 분산 과정을 거쳐 합성하게 되는데, 흑연을 산화시키는 단계에서 흑연의 산화 정도를 조절함으로써 그래핀 옥사이드 입자의 적층 개수의 조절이 가능하게 된다. 환원 그래핀 옥사이드 입자의 층구조가 상기와 같을 때 환원 그래핀 옥사이드 코팅시에 결점(defect)이 발생할 확률을 현저하게 낮추고, 제조된 환원 그래핀 옥사이드층의 기계적 물성을 향상시키는 효과가 발생하게 된다.According to a specific embodiment of the present invention, the reduced graphene oxide sheet may be in the form of a layer structure of 1 to 3 reduced graphene oxide particles, for example, reduced graphene oxide platelet particles. The layer structure of the reduced graphene oxide should be made before the reduction reaction of the graphene oxide. In general, graphene oxide is synthesized after oxidizing graphite through an ultrasonic dispersion process. By controlling the degree of oxidation of graphite in the step of oxidizing graphite, it is possible to control the number of stacked graphene oxide particles. When the layer structure of the reduced graphene oxide particles is as described above, the probability of occurrence of defects when coating the reduced graphene oxide is significantly reduced, and an effect of improving the mechanical properties of the prepared reduced graphene oxide layer occurs. .
본 발명의 구체적인 일 실시양태에 따르면, 상기 환원 그래핀 옥사이드 시트는 0.002 내지 10 ㎛, 또는 0.005 내지 1 ㎛ 범위, 또는 0.01 내지 0.1 ㎛ 범위의 두께를 가질 수 있다. 상기 환원 그래핀 옥사이드 시트가 상기 범위의 두께를 갖는 경우에 유연한 기계적 물성과 효과적인 수분 차단 효과를 가질 수 있다.According to one specific embodiment of the present invention, the reduced graphene oxide sheet may have a thickness in the range of 0.002 to 10 μm, or 0.005 to 1 μm, or 0.01 to 0.1 μm. When the reduced graphene oxide sheet has a thickness in the above range, it may have flexible mechanical properties and effective moisture blocking effect.
본 발명에서 치밀한 층간 간격을 얻기 위해 일정 수준 이상의 순도를 갖는 그래핀 옥사이드를 사용하는 것이 바람직하다. 예컨대, 93 % 이상, 또는 순도 97.5 % 이상, 또는 99.5 % 이상의 순도를 갖는 그래핀 옥사이드를 사용할 수 있다. 이와 관련하여, 본원 명세서에서 '순도'라 함은 그래핀 옥사이드와 금속 잔여물을 합한 중량 대비 그래핀 옥사이드의 중량비를 의미한다.In the present invention, it is preferable to use graphene oxide having a certain level of purity or more to obtain a dense interlayer spacing. For example, graphene oxide having a purity of 93% or higher, or a purity of 97.5% or higher, or 99.5% or higher may be used. In this regard, the term “purity” in the present specification means a weight ratio of graphene oxide to weight combined with graphene oxide and metal residue.
상기 그래핀 옥사이드를 코팅하기 위해, 그래핀 옥사이드를 분산매, 예컨대 물에 분산시켜서 분산조성물을 수득한다. In order to coat the graphene oxide, the graphene oxide is dispersed in a dispersion medium such as water to obtain a dispersion composition.
상기 그래핀 옥사이드를 코팅하기 위해, 금속염과 그래핀 옥사이드를 분산매, 예컨대 물 또는 탈이온수에 분산시켜서 분산조성물을 수득한다. To coat the graphene oxide, a metal salt and graphene oxide are dispersed in a dispersion medium such as water or deionized water to obtain a dispersion composition.
본 발명의 구체적인 일 실시양태에 따르면, 상기 금속염을 구성하는 금속 양이온은 Li +, K +, Ag +, Mg 2 +, Ca 2 +, Cu 2 +, Pb 2 +, Co 2 +, Al 3 +, Cr 3 +, Fe 3 + 또는 이들 중 2 이상일 수 있다. 상기 금속 양이온 중에서 금속 양이온 Al 3 +, Cr 3 +, 또는 Fe 3 +이 산화수가 높아 정전기적 인력을 효과적으로 발휘할 수 있기 때문에 특히 바람직하다. 상기 금속 양이온과 함께 금속염을 구성하는 음이온은 본 발명의 목적에 부합하는 한 특별히 제한되지 않으며, 비제한적인 예로 Cl -, NO 3 -, 또는 SO 4 2- 일 수 있다.According to one specific embodiment of the present invention, the metal cation constituting the metal salt is Li + , K + , Ag + , Mg 2 + , Ca 2 + , Cu 2 + , Pb 2 + , Co 2 + , Al 3 + , Cr 3 + , Fe 3 + or two or more of them. Among the metal cations, the metal cation Al 3 + , Cr 3 + , or Fe 3 + is particularly preferable because it has a high oxidation number and can effectively exhibit electrostatic attraction. Anion constituting the metal salt with said metal cation is not particularly limited as to meet the object of the present invention, non-limiting examples of Cl - may be, or SO 4 2- -, NO 3.
본 발명의 구체적인 일 실시양태에 따르면, 상기 금속염이 그래핀 옥사이드 입자의 중량 기준으로 0.01 내지 10 중량% 또는 0.01 내지 1 중량% 범위의 양으로 분산매에 투입될 수 있다. 상기 금속염이 전술한 범위의 양으로 사용되는 경우에 금속 양이온의 과량 투입시 금속 입자 형성으로 인해 환원 그래핀 시트 사이에 나노미터 수준의 갭이 발생하는 현상을 방지하는 동시에 적절한 정전기적 상호작용을 가질 수 있다.According to one specific embodiment of the present invention, the metal salt may be added to the dispersion medium in an amount ranging from 0.01 to 10% by weight or 0.01 to 1% by weight based on the weight of the graphene oxide particles. When the metal salt is used in an amount in the above-described range, when an excessive amount of metal cations is introduced, a nanometer-level gap between reducing graphene sheets is prevented due to formation of metal particles, and at the same time, proper electrostatic interaction is obtained. You can.
본 발명의 구체적인 일 실시양태에 따르면, 상기 분산조성물은 분산매 100 중량부에 대하여 약 0.0001 중량부 내지 약 0.01 중량부의 양으로 그래핀 옥사이드를 포함할 수 있다. 그래핀 옥사이드의 양이 상기 수치범위의 양으로 포함되는 경우에는 0.0001 중량부보다 많이 포함되어 그래핀 옥사이드층의 형성시 그래핀 옥사이드의 정렬을 유도할 수 있고, 0.01 중량부 이하로 사용되어 분산성을 확보하는 효과를 얻을 수 있다. 예를 들어, 상기 그래핀 옥사이드 분산조성물은 분산매 100 중량부에 대하여 그래핀 옥사이드 약 0.0001 중량부 내지 약 0.01 중량부, 약 0.0004 중량부 내지 약 0.01 중량부, 약 0.0004 중량부 내지 약 0.008 중량부, 또는 약 0.0004 중량부 내지 약 0.006 중량부가 포함되도록 제조되는 것일 수 있으나, 이에 제한되지 않을 수 있다.According to one specific embodiment of the present invention, the dispersion composition may include graphene oxide in an amount of about 0.0001 parts by weight to about 0.01 parts by weight based on 100 parts by weight of the dispersion medium. When the amount of graphene oxide is included in an amount in the above numerical range, it is contained more than 0.0001 parts by weight to induce the alignment of graphene oxide when the graphene oxide layer is formed, and is used in an amount of 0.01 parts by weight or less to disperse It can obtain the effect of securing. For example, the graphene oxide dispersion composition is about 0.0001 parts by weight to about 0.01 parts by weight, about 0.0004 parts by weight to about 0.01 parts by weight, about 0.0004 parts by weight to about 0.008 parts by weight, based on 100 parts by weight of the dispersion medium, Or it may be prepared to include from about 0.0004 parts by weight to about 0.006 parts by weight, but may not be limited thereto.
상기 분산은 초음파 분산기와 같은 초음파 발생기를 이용하는 것일 수 있으나, 이에 제한되지 않을 수 있다.The dispersion may be an ultrasonic generator such as an ultrasonic disperser, but may not be limited thereto.
본 발명의 일 실시양태에 있어서, 상기 그래핀 옥사이드 분산조성물은 그래핀 옥사이드 분산이 가능한 유기 용매를 더 포함하는 것일 수 있다. 상기 유기 용매의 비제한적인 예로는 알코올, 디메틸포름아마이드(Dimethyl formamide: DMF), 디메틸 설폭사이드(Dimethyl sulfoxide: DMSO), N-메틸 피롤리돈(N-methyl pyrrolidone), 메틸 페놀(methyl phenol, 크레졸(cresol) 또는 이들 중 2 이상의 혼합물을 더 포함하는 것일 수 있으나, 이에 제한되지 않을 수 있다. 상기 그래핀 옥사이드 분산조성물은 상기 분산매 100 체적%에 대하여 약 100 체적% 이하의 상기 그래핀 옥사이드 분산이 가능한 유기 용매를 더 포함하는 것일 수 있다. 예를 들어, 상기 그래핀 옥사이드 분산조성물은 상기 분산매 100 체적%에 대하여 약 1 부피% 내지 약 100 부피%, 약 20 부피% 내지 약 100 부피%, 20 부피% 내지 약 60 부피%, 또는 약 40 부피% 내지 약 60 부피%, 의 상기 그래핀 옥사이드 분산이 가능한 유기 용매를 추가 포함하는 것일 수 있으나, 이에 제한되지 않을 수 있다.In one embodiment of the present invention, the graphene oxide dispersion composition may further include an organic solvent capable of graphene oxide dispersion. Non-limiting examples of the organic solvent include alcohol, dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (N-methyl pyrrolidone), methyl phenol (methyl phenol, It may be a cresol (cresol) or a mixture of two or more of them, but may not be limited to this.The graphene oxide dispersion composition is less than about 100% by volume of the graphene oxide dispersion with respect to 100% by volume of the dispersion medium It may be to further include this possible organic solvent, for example, the graphene oxide dispersion composition is about 1% by volume to about 100% by volume, about 20% by volume to about 100% by volume relative to 100% by volume of the dispersion medium, 20% by volume to about 60% by volume, or about 40% by volume to about 60% by volume, may be to further include an organic solvent capable of dispersing the graphene oxide, but is not limited thereto. Can be
이어서, 상기 그래핀 옥사이드 분산조성물은 기계적 지지층 또는 실란트층상에 코팅된다. Subsequently, the graphene oxide dispersion composition is coated on a mechanical support layer or a sealant layer.
상기 코팅 방법의 비제한적인 예로, 바코팅(rod coating), 스핀 캐스팅(spin-casting), 드롭캐스팅(drop-casting), 진공필터링(vacuum filtering), 딥코팅 (dip-coating) 또는 전기영동코팅(electrophoretic coating)과 같은 방법이 사용될 수 있다. Non-limiting examples of the coating method, bar coating (rod coating), spin casting (spin-casting), drop-casting (drop-casting), vacuum filtering (vacuum filtering), deep coating (dip-coating) or electrophoretic coating (electrophoretic coating) may be used.
상기 코팅은 1초 이상의 코팅 시간을 확보함으로써 그래핀 옥사이드의 정렬을 유도하여 치밀한 막을 수득하고, 30분 이내의 코팅 시간으로 균일도 있는 막을 얻기 위한 효과를 기대하기 위해 1초 내지 30분, 또는 3초 내지 10분, 또는 5초 내지 5분의 시간 내에 수행될 수 있다. The coating induces alignment of graphene oxide by securing a coating time of 1 second or longer to obtain a dense film, and 1 second to 30 minutes, or 3 seconds in order to expect an effect to obtain a uniform film with a coating time within 30 minutes. To 10 minutes, or 5 seconds to 5 minutes.
또한, 상기 코팅은 1회 이상의 코팅 횟수를 확보함으로써 충분한 그래핀 옥사이드층을 치밀하게 형성할 수 있고, 30회 이내의 코팅 횟수로 불필요하게 두꺼운 층의 형성을 억제하기 위한 효과를 기대하기 위해 1 내지 30회, 또는 1 내지 10 회, 또는 1 내지 5회의 횟수에 걸쳐 코팅될 수 있다. 이 경우, 1회 코팅시에 그래핀 옥사이드 분산조성물 1 mL 내지 1000 mL, 또는 3 mL 내지 200 mL, 또는 10 mL 내지 100 mL의 양이 사용될 수 있다.In addition, the coating can securely form a sufficient graphene oxide layer by securing the number of coatings one or more times, and in order to expect an effect for suppressing the formation of a thick layer unnecessarily with the number of coatings within 30 times, 1 to It may be coated over 30 times, or 1 to 10 times, or 1 to 5 times. In this case, the amount of graphene oxide dispersion composition 1 mL to 1000 mL, or 3 mL to 200 mL, or 10 mL to 100 mL may be used in one coating.
본 발명의 구체적인 일 실시양태에 따르면, 건조된 그래핀 옥사이드층은 20 nm 이상의 두께를 가짐으로써 수분차단성을 확보하고, 30 ㎛ 이하의 두께를 가짐으로써 기계적 물성을 확보하는 효과를 가지며, 이러한 효과를 위해 건조된 그래핀 옥사이드층은 20 nm 내지 30 ㎛, 또는 100 nm 내지 10 ㎛, 또는 500 nm 내지 5 ㎛ 범위의 두께를 가질 수 있다. According to one specific embodiment of the present invention, the dried graphene oxide layer has an effect of securing moisture barrier properties by having a thickness of 20 nm or more, and securing mechanical properties by having a thickness of 30 μm or less, and this effect The dried graphene oxide layer may have a thickness in the range of 20 nm to 30 μm, or 100 nm to 10 μm, or 500 nm to 5 μm.
수득된 그래핀 옥사이드층은 수분 차단 필름의 수분 차단 특성이 극대화되도록 환원되어, 환원된 그래핀 옥사이드층으로 형성된다.The obtained graphene oxide layer is reduced to maximize the moisture barrier properties of the moisture barrier film, thereby forming a reduced graphene oxide layer.
상기 그래핀 옥사이드층의 환원을 위해, 요오드산(HI)을 이용한 환원법 또는 비타민 C를 이용한 환원법이 수행될 수 있다.For the reduction of the graphene oxide layer, a reduction method using iodic acid (HI) or a reduction method using vitamin C may be performed.
상기 요오드산을 이용한 환원법의 경우, 요오드산 용액이 들어있는 용기 및 제조된 그래핀 옥사이드층을 밀폐 공간, 예컨대 유리 페트리 디쉬에 함께 넣는 단계, 10 ℃ 내지 100 ℃ 범위의 온도로 1분 내지 1시간동안 열처리하여 요오드산을 기화시키는 단계, 및 기화된 요오드산과 함께 그래핀 옥사이드층을 2분 내지 3시간동안 유지시키는 단계에 의해 그래핀 옥사이드가 환원 그래핀 옥사이드로 전환되어, 환원 그래핀 옥사이드층이 수득될 수 있다. In the case of the reduction method using iodic acid, the container containing the iodic acid solution and the prepared graphene oxide layer are put together in a closed space, such as a glass petri dish, for 1 minute to 1 hour at a temperature in the range of 10 ° C to 100 ° C During the heat treatment, the graphene oxide is converted into reduced graphene oxide by the step of vaporizing iodic acid, and maintaining the graphene oxide layer together with the vaporized iodic acid for 2 minutes to 3 hours, thereby reducing the graphene oxide layer. Can be obtained.
또는, 제조된 그래핀 옥사이드층을 10 내지 100 ℃, 예컨대 90 ℃ 요오드산 용액에 함침시켜서 그래핀 옥사이드층이 환원 그래핀 옥사이드층으로 전환되는 단계, 및 환원 그래핀 옥사이드층을 증류수로 세척하는 단계에 의해 환원 그래핀 옥사이드층이 수득될 수 있다. 수득된 환원 그래핀 옥사이드층은 에탄올로 세척될 수 있다.Alternatively, the graphene oxide layer is impregnated with a solution of iodic acid at 10 to 100 ° C, such as 90 ° C, so that the graphene oxide layer is converted into a reduced graphene oxide layer, and washing the reduced graphene oxide layer with distilled water. A reduced graphene oxide layer can be obtained. The reduced graphene oxide layer obtained can be washed with ethanol.
상기 비타민 C를 이용한 환원법의 경우, 예를 들어 아스코르브산을 증류수에 용해시켜 0.01 mg/mL 내지 5 mg/mL, 또는 0.05 mg/mL 내지 0.3 mg/mL 농도의 아스코르브산 용액을 형성시키는 단계; 및 상기 아스코르브산 용액을 25 내지 90 ℃ 범위의 온도로 조절하고, 여기에 그래핀 옥사이드층을 함침시켜 환원시키는 단계에 의해 환원 그래핀 옥사이드층을 형성할 수 있다.In the case of the reduction method using vitamin C, for example, dissolving ascorbic acid in distilled water to form an ascorbic acid solution having a concentration of 0.01 mg / mL to 5 mg / mL, or 0.05 mg / mL to 0.3 mg / mL; And it is possible to form a reduced graphene oxide layer by adjusting the ascorbic acid solution to a temperature in the range of 25 to 90 ° C. and impregnating the graphene oxide layer to reduce it.
상기로부터 수득된 환원 그래핀 옥사이드층은 수분 및/또는 가스의 유입을 차단할 수 있는 구조를 가지며, 예컨대, 0.3 nm 내지 5.0 nm 범위, 또는 0.3 nm 내지 0.7 nm 범위의 환원 그래핀 옥사이드 시트 인터레이어 간격을 가질 수 있다.The reduced graphene oxide layer obtained from the above has a structure capable of blocking the inflow of moisture and / or gas, for example, a reduced graphene oxide sheet interlayer spacing in the range of 0.3 nm to 5.0 nm, or 0.3 nm to 0.7 nm. Can have
본원 명세서에서 사용될 때 용어 "인터레이어 간격"은 환원 그래핀 옥사이드 시트 사이의 간격, 즉, 환원 그래핀 옥사이드 시트간 간격을 의미한다.As used herein, the term "interlayer spacing" refers to the spacing between sheets of reduced graphene oxide, that is, the spacing between sheets of reduced graphene oxide.
본 발명과 달리, 환원 그래핀 옥사이드층을 구성하는 환원 그래핀 옥사이드 시트 사이에 정전기적 상호작용이 없으면, 상기 환원 그래핀 옥사이드 시트 사이에 화학적 및/또는 물리적 연결체가 없기 때문에 수분 차단에 대한 결함(defect)으로 작용할 수 있다. 그 결과, 상기 환원 그래핀 옥사이드 시트들 사이를 수분 입자가 통과하게 되므로, 궁극적으로는, 상기 환원 그래핀 옥사이드층을 포함하여 형성된 이차전지 패키징용 필름으로 패키징된 전지의 성능이 악화되는 원인으로 작용할 수 있다.Unlike the present invention, if there is no electrostatic interaction between the reduced graphene oxide sheets constituting the reduced graphene oxide layer, there is no chemical and / or physical linkage between the reduced graphene oxide sheets, thereby preventing moisture barrier defects ( defect). As a result, since water particles pass between the reduced graphene oxide sheets, ultimately, the performance of a battery packaged with a film for packaging a secondary battery formed by including the reduced graphene oxide layer may deteriorate. You can.
상기 실란트층이 상기 환원 그래핀 옥사이드층의 타측에 직접 또는 접착층을 사이에 두고 형성되어 있어, 전극조립체의 외면을 둘러싼 후에 전극조립체가 외부로부터 차단될 수 있다. Since the sealant layer is formed directly on the other side of the reduced graphene oxide layer or with an adhesive layer therebetween, the electrode assembly may be blocked from the outside after surrounding the outer surface of the electrode assembly.
상기 실란트층은 열에 의하여 접착되는 열접착성 또는 열융착성을 가지며, 각각 독립적으로 폴리프로필렌-아크릴산 공중합체, 폴리에틸렌-아크릴산 공중합체, 염화폴리프로필렌, 폴리프로필렌-부틸렌-에틸렌 삼원공중합체, 폴리프로필렌, 폴리에틸렌 및 에틸렌 프로필렌 공중합체로 이루어진 군에서 선택되는 적어도 어느 하나 이상을 포함할 수 있으며 이에 한정되지 아니한다.The sealant layer has a heat-adhesive or heat-sealable adhesive adhered by heat, and each independently polypropylene-acrylic acid copolymer, polyethylene-acrylic acid copolymer, polypropylene chloride, polypropylene-butylene-ethylene terpolymer, poly It may include at least one or more selected from the group consisting of propylene, polyethylene and ethylene propylene copolymer, but is not limited thereto.
본 발명의 다른 측면에 따르면, 상기 기계적 지지층과 상기 환원 그래핀 옥사이드층의 사이, 또한 상기 환원 그래핀 옥사이드층과 상기 실란트층의 사이에 점착력이 부족할 수 있으므로, 상기 기계적 지지층, 상기 환원 그래핀 옥사이드층, 상기 실란트층 중 서로 대면하는 층사이에 접착층을 더 포함할 수 있다. 이를 통하여 접착특성 및 수분 차단 특성을 더욱 향상시킬 수 있다. 상기 접착층의 소재로는 예를 들어, 우레탄계 물질, 아크릴계 물질, 열가소성 엘라스토머를 함유하는 조성물이 있으며 이에 한정되지 아니한다. According to another aspect of the invention, between the mechanical support layer and the reduced graphene oxide layer, and also between the reduced graphene oxide layer and the sealant layer may have insufficient adhesion, the mechanical support layer, the reduced graphene oxide A layer may further include an adhesive layer between the sealant layers facing each other. Through this, it is possible to further improve the adhesion properties and the moisture barrier properties. The material of the adhesive layer includes, for example, a composition containing a urethane-based material, an acrylic material, and a thermoplastic elastomer, but is not limited thereto.
본 발명의 구체적인 일 실시양태에 따르면, 전술한 구조를 갖는 수분 차단 필름은 1 ㎛ 내지 1000 ㎛, 또는 10 ㎛ 내지 500 ㎛, 또는 20 ㎛ 내지 200 ㎛ 범위의 두께를 가질 수 있다. 이 경우에 10 -6 g/m 2/day 내지 10 -3 g/m 2/day, 또는 10 -6 g/m 2/day 내지 10 -4 g/m 2/day, 또는 10 -6 g/m 2/day 내지 10 -5 g/m 2/day 범위의 WVTR(수증기 투과속도, Water Vapor Transmission Rate)을 가질 수 있다. 따라서, 이차전지 패키징에서 요구되는 수분 차단성 요건을 충족시킬 수 있다.According to one specific embodiment of the present invention, the moisture barrier film having the above-described structure may have a thickness in the range of 1 μm to 1000 μm, or 10 μm to 500 μm, or 20 μm to 200 μm. In this case 10 -6 g / m 2 / day to 10 -3 g / m 2 / day, or 10 -6 g / m 2 / day to 10 -4 g / m 2 / day, or 10 -6 g / It may have a water vapor transmission rate (WVTR) in the range of m 2 / day to 10 -5 g / m 2 / day. Therefore, it is possible to meet the moisture barrier properties required in secondary battery packaging.
본원 명세서에서 "WVTR" 또는 "수증기 투과속도"는 그 수치가 낮을수록 수분 내지는 습기에 대하여 우수한 차단능을 가짐을 의미하며, ASTM F-1249에 따라 37.8 ℃, 100% 습도에서 측정한다.In this specification, "WVTR" or "water vapor permeation rate" means that the lower the value is, the better the moisture or moisture has a blocking ability, and is measured at 37.8 ° C and 100% humidity according to ASTM F-1249.
플렉서블 이차전지용 패키징은 상기 수분 차단 필름에 부가하여 열수축 튜브를 더 포함하며, 그의 비제한적인 실시양태가 도 8과 도 9에 도시되어 있다.The packaging for the flexible secondary battery further includes a heat shrink tube in addition to the moisture barrier film, and non-limiting embodiments thereof are illustrated in FIGS. 8 and 9.
도 8을 살펴보면, 전극조립체(C) 외면을 수분 차단 필름(F)이 둘러싸고 있되, 실란트층(400)이 전극조립체를 향하도록 배치되어 있다. 상기 수분 차단 필름은 양 단부의 소정 부분이 겹쳐진 형태로 상기 전극조립체의 외면을 둘러싸는 관 형태를 이루고, 상기 수분 차단 필름의 서로 겹쳐진 양 단부의 대향하는 실란트층이 열 압착되어 실링부를 형성한다. 상기 실링부는 상기 수분 차단 필름의 둘레를 따라 폴딩된 날개부를 형성하게 된다. 이후, 열수축 튜브(T)가 적용된다.8, the outer surface of the electrode assembly (C) is surrounded by a moisture barrier film (F), the sealant layer 400 is disposed to face the electrode assembly. The moisture barrier film forms a tube that surrounds the outer surface of the electrode assembly in a form in which predetermined portions of both ends overlap, and opposing sealant layers of both ends overlapping each other of the moisture barrier film are thermally compressed to form a sealing portion. The sealing portion forms a folded wing portion along the periphery of the moisture barrier film. Then, a heat shrink tube (T) is applied.
도 9를 살펴보면, 전극조립체(C) 외면을 수분 차단 필름(F)이 둘러싸고 있되, 수분 차단 필름의 양쪽 타측 각각에 제1 실린트층(표기되지 않음)과 제2 실란트층(표기되지 않음)이 구비되어 있다. 상기 수분 차단 필름은 상기 전극조립체의 외면을 둘러싸는 관 형태이고, 상기 수분 차단 필름의 한쪽 단부 일면의 제1 실란트층과 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹쳐서 접착되어 있다. 이후, 열수축 튜브(T)가 적용된다.Referring to Figure 9, the outer surface of the electrode assembly (C) is surrounded by a moisture barrier film (F), the first sealant layer (not shown) and the second sealant layer (not shown) on each side of the other side of the moisture barrier film It is equipped. The moisture barrier film is in the form of a tube surrounding the outer surface of the electrode assembly, and the first sealant layer on one end of the moisture barrier film and the second sealant layer on the other end of the other end portion are adhered to each other by overlapping each other. Then, a heat shrink tube (T) is applied.
본 발명에 있어서 '소정 부분'이란, 수분 차단 필름이 전극조립체의 외면을 둘러쌀 때, 상기 수분 차단 필름의 길이가 전극조립체의 둘레보다 더 길어서, 상기 수분 차단 필름의 실란트층이 겹쳐지는 부분이 존재하는 것을 의미한다. 예를 들어, 상기 소정 부분은 전극조립체 외면 둘레의 1 내지 99%, 또는 1 내지 70%가 될 수 있으며, 또는 3 내지 50%, 또는 5 내지 30%가 될 수 있다. In the present invention, the term 'predetermined portion' means that when the moisture barrier film surrounds the outer surface of the electrode assembly, the length of the moisture barrier film is longer than the circumference of the electrode assembly, so that the sealant layer of the moisture barrier film overlaps. It means to exist. For example, the predetermined portion may be 1 to 99%, or 1 to 70%, or 3 to 50%, or 5 to 30% around the outer surface of the electrode assembly.
상기 열수축 튜브는 가열하면 수축하는 튜브로서, 단자(端子) 또는 형태나 크기가 다른 물질을 빈틈없이 꽉 싸게 되는 물질을 의미한다. 본 발명에서는 상기 수분 차단 필름을 전극조립체 외면에 일부분 겹치게 감싸고, 이를 열수축 튜브에 삽입한 이후에 열을 가하게 되면, 상기 열수축 튜브를 통하여 전해지는 열에 의하여 수분 차단 필름의 실링 폴리머가 녹으면서 수분 차단 필름의 실링이 진행되며, 동시에 열수축 튜브가 가열되면서 수축되어, 상기 전극조립체 외면을 둘러쌓은 수분 차단 필름과 열수축 튜브 사이를 빈틈없이 타이트한 패키징을 제공할 수 있다. 빈틈없는 타이트한 패키징을 통하여 패키징의 수분 차단 성능을 보다 더 향상시키게 되며, 열수축 튜브를 통하여 절연의 효과도 동시에 얻을 수 있다. 또한, 열수축 튜브만 사용하게 되면 열수축 튜브의 그 구조상 기공이 존재하여 수분이 전지 내부로 유입되는 현상이 발생되기도 하지만, 본 발명은 수분 차단 필름 및 열수축 튜브를 모두 포함하여서 수분 차단의 효과와 함께 이차전지의 보호 역할을 충분히 하도록 하였다.The heat-shrinkable tube is a tube that contracts when heated, and means a material that tightly wraps a terminal or a material having a different shape or size. In the present invention, the moisture barrier film is partially wrapped on the outer surface of the electrode assembly, and when heat is applied after being inserted into the heat shrink tube, the sealing polymer of the moisture barrier film is melted by heat transmitted through the heat shrink tube and the moisture barrier film melts. The sealing proceeds, and at the same time, the heat-shrinkable tube is shrunk while being heated, thereby providing tight packaging tightly between the heat-shrinkable tube and the moisture barrier film surrounding the outer surface of the electrode assembly. Through tight and tight packaging, the moisture barrier performance of the packaging is further improved, and the effect of insulation can be obtained simultaneously through the heat shrink tube. In addition, when only the heat-shrinkable tube is used, there may be a phenomenon in which moisture is introduced into the battery due to the presence of pores in the structure of the heat-shrinkable tube. It was made to sufficiently protect the battery.
상기 열수축 튜브는 다양한 재질 및 형태를 갖는 열수축 튜브가 상용화되어 있으므로, 본 발명의 목적에 적합한 것을 용이하게 입수하여 사용할 수 있다. 이차전지의 열적 손상을 주지 않도록, 수축 가공의 온도를 저온으로 하는 것이 필요하며, 일반적으로는 70 내지 200 ℃, 또는 70 내지 150 ℃, 또는 100 내지 150 ℃, 또는 70 내지 120 ℃의 온도로 수축이 완료되는 것이 요구된다. 이를 위해, 상기 열수축층은 폴리에틸렌, 폴리프로필렌 등의 폴리올레핀, 폴리에틸렌테레프탈레이트 등의 폴리에스테르계, 폴리비닐리덴플루오라이드, 폴리테트라플루오로에틸렌 등의 플루오로수지 및 폴리염화비닐 등으로 이루어진 군으로 선택되는 어느 하나, 또는 이들 중 2종 이상을 개질한 고분자로부터 형성될 수 있다. Since the heat-shrinkable tube is a commercialized heat-shrinkable tube having various materials and shapes, it can be easily obtained and used for the purpose of the present invention. To avoid thermal damage to the secondary battery, it is necessary to reduce the temperature of the shrinking process to a low temperature, and generally shrink to a temperature of 70 to 200 ° C, or 70 to 150 ° C, or 100 to 150 ° C, or 70 to 120 ° C It is required to be completed. To this end, the heat shrink layer is selected from the group consisting of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, fluororesins such as polyvinylidene fluoride and polytetrafluoroethylene, and polyvinyl chloride. It can be formed from any one, or a polymer modified two or more of them.
본 발명에 따르면 상기 플렉서블 이차전지용 패키징을 포함하는 플렉서블 이차전지가 제공된다.According to the present invention, a flexible secondary battery including the packaging for the flexible secondary battery is provided.
본 발명에 따른 플렉서블 이차전지는 내부전극, 상기 내부전극을 둘러싸며 형성된 전극의 단락을 방지하는 분리층 및 상기 분리층의 외면을 둘러싸며 형성된 외부전극을 포함하는 소정 형상의 수평 단면을 가지고 길이 방향으로 연장된 전극조립체; 및 상기 전극조립체의 전체 외면을 둘러싸며 밀착되는 본 발명에 따른 플렉서블형 플렉서블 이차전지용 패키징을 포함하게 된다.The flexible secondary battery according to the present invention has a horizontal cross section of a predetermined shape including an internal electrode, a separation layer to prevent shorting of an electrode formed surrounding the internal electrode, and an external electrode formed around an outer surface of the separation layer. Electrode assembly extended to; And packaging for a flexible type flexible secondary battery according to the present invention, which is in close contact with the entire outer surface of the electrode assembly.
본 발명에 있어서, '소정의 형상'이라 함은 특별히 형상을 제한하지 않는다는 것으로, 본 발명의 본질을 훼손하지 않는 어떠한 형상도 가능하다는 의미이다. 이러한 소정 형상의 수평단면은 원형 또는 다각형일 수 있는데, 원형 구조는 기하학적으로 완전한 대칭형의 원형과 비대칭형의 타원형 구조이다. 다각형 구조는 특별히 제한되는 것은 아니고, 이러한 다각형 구조의 비제한적인 예로는 삼각형, 사각형, 오각형 또는 육각형일 수 있다. In the present invention, the term 'predetermined shape' means that the shape is not particularly limited, and that any shape that does not impair the essence of the present invention is possible. The horizontal cross-section of the predetermined shape may be circular or polygonal, and the circular structure is a geometrically complete symmetrical circular shape and an asymmetrical oval shape. The polygonal structure is not particularly limited, and non-limiting examples of the polygonal structure may be triangular, square, pentagonal or hexagonal.
본 발명의 플렉서블 이차전지는 소정의 형상의 수평 단면을 가지며, 수평 단면의 길이방향으로 길게 늘어진 선형구조를 갖고, 가요성을 가지므로 변형이 자유롭다.The flexible secondary battery of the present invention has a horizontal cross-section of a predetermined shape, has a linear structure elongated in the longitudinal direction of the horizontal cross-section, has flexibility and is free from deformation.
본 발명에 있어서, 상기 전극조립체의 내부전극은 전해질을 포함하는 리튬이온 공급 코어부, 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체와 상기 내부집전체의 표면에 형성된 내부전극 활물질층을 구비할 수 있다. In the present invention, the internal electrode of the electrode assembly is a lithium ion supply core portion including an electrolyte, an internal current collector having an open structure formed surrounding an outer surface of the lithium ion supply core portion, and an internal electrode formed on the surface of the internal current collector. An active material layer may be provided.
상기 열린 구조라 함은 그 열린 구조를 경계면으로 하고, 이러한 경계면을 통하여 내부에서 외부로의 물질의 이동이 자유로운 형태의 구조를 말한다. The open structure refers to a structure in which the open structure is used as a boundary surface, and the material can be freely moved from inside to outside through the boundary surface.
상기 리튬이온 공급 코어부는 전해질을 포함할 수 있으며, 이러한 전해질로는 그 종류를 특별히 한정하는 것은 아니지만 에틸렌카보네이트(EC), 프로필렌카보네이트(PC), 부틸렌카보네이트(BC), 비닐렌카보네이트(VC), 디에틸카보네이트(DEC), 디메틸카보네이트(DMC), 에틸메틸카보네이트(EMC), 메틸포르메이트(MF), 감마-부티로락톤(γ-BL;butyrolactone), 설포레인(sulfolane), 메틸아세테이트(MA; methylacetate), 또는 메틸프로피오네이트(MP; methylpropionate)를 사용한 비수전해액; PEO, PVdF, PMMA, PAN 또는 PVAC를 사용한 겔형 고분자 전해질; 또는 PEO, PPO(polypropylene oxide), PEI(polyethylene imine), PES(polyethylene sulphide) 또는 PVAc(polyvinyl acetate)를 사용한 고체 전해질; 등을 사용할 수 있다. 그리고, 이러한 전해질은 리튬염을 더 포함할 수 있는데, 이러한 리튬염으로는 LiCl, LiBr, LiI, LiClO4, LiBF 4, LiB 10Cl 10, LiPF 6, LiCF 3SO 3, LiCF 3CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3SO 3Li, CF 3SO 3Li, (CF 3SO 2) 2NLi, 클로로보란리튬, 저급 지방족 카르본산리튬 및 테트라페닐붕산리튬 등을 사용하는 것이 바람직하다. 그리고, 이러한 리튬이온 공급 코어부는 전해질로만 구성될 수 있으며, 액상의 전해액의 경우에는 다공질의 담체를 사용하여 구성될 수도 있다.The lithium ion supply core portion may include an electrolyte, and the type of the electrolyte is not particularly limited, but ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and vinylene carbonate (VC) are not limited. , Diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl formate (MF), gamma-butyrolactone (γ-BL; butyrolactone), sulfolane, methyl acetate (MA; methylacetate), or a non-aqueous electrolyte solution using methyl propionate (MP); Gel polymer electrolytes using PEO, PVdF, PMMA, PAN or PVAC; Or a solid electrolyte using PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES) or polyvinyl acetate (PVAc); Etc. can be used. In addition, the electrolyte may further include a lithium salt, such as LiCl, LiBr, LiI, LiClO4, LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, chloroboranlithium, lower aliphatic lithium carboxylate, lithium tetraphenylborate, and the like are preferably used. In addition, the lithium ion supply core portion may be composed of only an electrolyte, and in the case of a liquid electrolyte, it may also be configured using a porous carrier.
본 발명의 내부집전체는 리튬이온 공급 코어부의 전해질의 침투가 용이하도록 열린 구조를 가지며, 이러한 열린 구조로는 전해질의 침투가 용이한 형태의 구조라면 모두 채택이 가능하다. The internal current collector of the present invention has an open structure to facilitate the penetration of the electrolyte in the lithium ion supply core, and such an open structure can be adopted as long as the structure has an easy penetration of the electrolyte.
상기 내부집전체로는 스테인리스스틸, 알루미늄, 니켈, 티탄, 소성탄소, 구리 또는 스테인리스스틸의 표면에 카본, 니켈, 티탄, 은으로 표면처리한 것, 알루미늄-카드뮴합금, 도전재로 표면처리된 비전도성 고분자, 또는 전도성 고분자를 사용하여 제조된 것이 바람직하다.The internal current collector is a surface treated with carbon, nickel, titanium, or silver on the surface of stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel, and a vision treated with aluminum-cadmium alloy and a conductive material. It is preferable to use a conductive polymer or a conductive polymer.
집전체는 활물질의 전기화학 반응에 의해 생성된 전자를 모으거나 전기화학 반응에 필요한 전자를 공급하는 역할을 하는 것으로, 일반적으로 구리나 알루미늄 등의 금속을 사용한다. 특히, 도전재로 표면처리된 비전도성 고분자 또는 전도성 고분자로 이루어진 고분자 전도체를 사용하는 경우에는 구리나 알루미늄과 같은 금속을 사용한 경우보다 상대적으로 가요성이 우수하다. 또한, 금속 집전체를 대체하여 고분자 집전체를 사용하여 전지의 경량성을 달성할 수 있다.The current collector serves to collect electrons generated by the electrochemical reaction of the active material or to supply electrons necessary for the electrochemical reaction, and generally metals such as copper or aluminum are used. In particular, when a non-conductive polymer surface-treated with a conductive material or a polymer conductor made of a conductive polymer is used, it is relatively more flexible than a metal such as copper or aluminum. In addition, it is possible to achieve light weight of the battery by using a polymer current collector by replacing the metal current collector.
이러한 도전재로는 폴리아세틸렌, 폴리아닐린, 폴리피롤, 폴리티오펜 및 폴리설퍼니트리드, ITO(Indum Thin Oxide), 은, 팔라듐 및 니켈 등이 가능하며, 전도성 고분자는 폴리아세틸렌, 폴리아닐린, 폴리피롤, 폴리티오펜 및 폴리설퍼니트리드 등이 사용가능하다. 다만, 집전체에 사용되는 비전도성 고분자는 특별히 종류를 한정하지는 않는다.Examples of the conductive material include polyacetylene, polyaniline, polypyrrole, polythiophene and polysulfurnitride, ITO (Indum Thin Oxide), silver, palladium, and nickel, and conductive polymers include polyacetylene, polyaniline, polypyrrole, and polyt Offen and polysulfuride can be used. However, the non-conductive polymer used in the current collector is not particularly limited.
본 발명의 내부전극 활물질층은 상기 내부집전체의 표면에 형성된다. 이때, 상기 내부집전체의 외면을 둘러싸며 형성되어 내부집전체 열린 구조가 내부전극 활물질층의 외면으로 노출되지 않는 경우뿐만 아니라, 내부전극 활물질층이 상기 내부집전체의 열린 구조의 표면에 형성되어 상기 내부집전체의 열린 구조가 내부전극 활물질층의 외면으로 노출되는 경우도 포함한다. 예를 들면, 권선된 와이어형 집전체의 표면에 활물질층을 형성하는 경우와 전극 활물질층이 형성된 와이어형 집전체를 권선하여 사용하는 경우를 들 수 있다.The inner electrode active material layer of the present invention is formed on the surface of the inner current collector. At this time, it is formed around the outer surface of the inner current collector, as well as when the inner current collector open structure is not exposed to the outer surface of the inner electrode active material layer, the inner electrode active material layer is formed on the surface of the open structure of the inner current collector Also included is the case where the open structure of the inner current collector is exposed to the outer surface of the inner electrode active material layer. For example, a case where an active material layer is formed on the surface of a wound wire-type current collector and a case where a wire-type current collector having an electrode active material layer is formed by winding are used.
본 발명의 외부집전체로는 특별히 그 형태를 제한하는 것은 아니지만, 파이프형 집전체, 권선된 와이어형 집전체 또는 메쉬형 집전체인 것을 사용할 수 있다. 그리고, 이로한 외부집전체로는 스테인리스스틸, 알루미늄, 니켈, 티탄, 소성탄소, 구리; 카본, 니켈, 티탄 또는 은으로 표면처리된 스테인리스스틸; 알루미늄-카드뮴합금; 도전재로 표면처리된 비전도성 고분자; 전도성 고분자; Ni, Al, Au, Ag, Al, Pd/Ag, Cr, Ta, Cu, Ba 또는 ITO인 금속분말을 포함하는 금속 페이스트; 또는 흑연, 카본블랙 또는 탄소나노튜브인 탄소분말을 포함하는 탄소 페이스트;로 제조된 것을 사용할 수 있다.The external current collector of the present invention is not particularly limited in form, but a pipe-type current collector, a wound wire-type current collector, or a mesh-type current collector can be used. In addition, the external current collector may include stainless steel, aluminum, nickel, titanium, calcined carbon, and copper; Stainless steel surface-treated with carbon, nickel, titanium or silver; Aluminum-cadmium alloy; A non-conductive polymer surface-treated with a conductive material; Conductive polymers; A metal paste containing a metal powder that is Ni, Al, Au, Ag, Al, Pd / Ag, Cr, Ta, Cu, Ba or ITO; Alternatively, a carbon paste containing carbon powder that is graphite, carbon black, or carbon nanotubes may be used.
상기 내부전극은 음극 또는 양극일 수 있으며, 상기 외부전극은 상기 외부전극과 대응하는 양극 또는 음극일 수 있다.The internal electrode may be a cathode or an anode, and the external electrode may be an anode or a cathode corresponding to the external electrode.
본 발명의 전극 활물질층은 집전체를 통해서 이온을 이동시키는 작용을 하고, 이들 이온의 이동은 전해질층으로부터의 이온의 흡장 및 전해질층으로의 이온의 방출을 통한 상호작용에 의한다. 이러한 전극 활물질층은 천연흑연, 인조흑연, 탄소질재료; 리튬 함유 티타늄 복합 산화물(LTO), Si, Sn, Li, Zn, Mg, Cd, Ce, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 상기 금속류(Me)의 산화물(MeO x); 및 상기 금속류(Me)와 탄소와의 복합체를 포함할 수 있고, 양극 활물질층으로 LiCoO 2, LiNiO 2, LiMn 2O 4, LiCoPO 4, LiFePO 4, LiNiMnCoO 2 및 LiNi 1 -x-y-zCo xM1 yM2 zO 2(M1 및 M2는 서로 독립적으로 Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg 및 Mo로 이루어진 군으로부터 선택된 어느 하나이고, x, y 및 z는 서로 독립적으로 산화물 조성 원소들의 원자 분율로서 0 ≤ x < 0.5, 0 ≤ y < 0.5, 0 ≤ z < 0.5, x+y+z ≤ 1임)을 사용 가능하다.The electrode active material layer of the present invention functions to move ions through a current collector, and the movement of these ions is caused by interaction through absorption of ions from the electrolyte layer and release of ions to the electrolyte layer. The electrode active material layer is natural graphite, artificial graphite, carbonaceous material; Lithium-containing titanium composite oxides (LTO), metals (Me) which are Si, Sn, Li, Zn, Mg, Cd, Ce, Ni, or Fe; Alloys composed of the metals (Me); Oxides (MeO x ) of the metals (Me); And may include a complex of the metal (Me) and carbon, as a positive electrode active material layer LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCoPO 4 , LiFePO 4 , LiNiMnCoO 2 And LiNi 1 -xyz Co x M1 y M2 z O 2 (M1 and M2 are each independently selected from the group consisting of Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo, and x, y and z are Independently, 0 ≤ x <0.5, 0 ≤ y <0.5, 0 ≤ z <0.5, and x + y + z ≤ 1) may be used as atomic fractions of oxide composition elements.
본 발명의 분리층은 전해질층 또는 세퍼레이터를 사용할 수 있다.The separation layer of the present invention may use an electrolyte layer or a separator.
이러한 이온의 통로가 되는 전해질층으로는 PEO, PVdF, PMMA, PAN 또는 PVAC를 사용한 겔형 고분자 전해질 또는 PEO, PPO(polypropylene oxide), PEI(polyethylene imine), PES(polyethylene sulphide) 또는 PVAc(polyvinyl acetate)를 사용한 고체 전해질 등을 사용한다. 고체 전해질의 매트릭스(matrix)는 고분자 또는 세라믹 글라스를 기본골격으로 하는 것이 바람직하다. 일반적인 고분자 전해질의 경우에는 이온전도도가 충족되더라도 반응속도적 측면에서 이온이 매우 느리게 이동할 수 있으므로, 고체인 경우보다 이온의 이동이 용이한 겔형 고분자의 전해질을 사용하는 것이 바람직하다. 겔형 고분자 전해질은 기계적 특성이 우수하지 않으므로 이를 보완하기 위해서 기공구조 지지체 또는 가교 고분자를 포함할 수 있다. 본 발명의 전해질층은 세퍼레이터의 역할이 가능하므로 별도의 세퍼레이터를 사용하지 않을 수 있다.The electrolyte layer used as a passage for these ions is a gel polymer electrolyte or PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES), or polyvinyl acetate (PVAc) using PEO, PVdF, PMMA, PAN or PVAC A solid electrolyte or the like is used. The matrix of the solid electrolyte is preferably a polymer or ceramic glass as a basic skeleton. In the case of a general polymer electrolyte, even if the ionic conductivity is satisfied, the ions can move very slowly in terms of reaction rate. Therefore, it is preferable to use an electrolyte of a gel polymer that facilitates ionic movement than a solid. Since the gel polymer electrolyte is not excellent in mechanical properties, a pore structure support or a crosslinked polymer may be included to compensate for this. Since the electrolyte layer of the present invention can function as a separator, a separate separator may not be used.
본 발명의 전해질층은, 리튬염을 더 포함할 수 있다. 리튬염은 이온 전도도 및 반응속도를 향상시킬 수 있는데, 이들의 비제한적인 예로는, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10Cl 10, LiPF 6, LiCF 3SO 3, LiCF 3CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3SO 3Li, CF 3SO 3Li, (CF 3SO 2) 2NLi, 클로로보란리튬, 저급지방족카르본산리튬 및 테트라페닐붕산리튬을 사용할 수 있다. The electrolyte layer of the present invention may further include a lithium salt. Lithium salt may improve the ionic conductivity and reaction rate, and non-limiting examples of these include LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiAlCl 4, CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2 NLi, chloro may borane lithium, lower aliphatic carboxylic acid lithium, and tetraphenyl lithium borate available .
상기 세퍼레이터로는 그 종류를 한정하는 것은 아니지만 에틸렌 단독중합체, 프로필렌 단독중합체, 에틸렌-부텐 공중합체, 에틸렌-헥센 공중합체 및 에틸렌-메타크릴레이트 공중합체로 이루어진 군에서 선택된 폴리올레핀계 고분자로 제조한 다공성 기재; 폴리에스테르, 폴리아세탈, 폴리아미드, 폴리카보네이트, 폴리이미드, 폴리에테르에테르케톤, 폴리에테르설폰, 폴리페닐렌산화물, 폴리페닐렌설파이트 및 폴리에틸렌나프탈렌으로 이루어진 군에서 선택된 고분자로 제조한 다공성 기재; 또는 무기물 입자 및 바인더 고분자의 혼합물로 형성된 다공성 기재 등을 사용할 수 있다. 또한, 상기 세퍼레이터로는 전술한 고분자로 제조한 다공성 기재의 적어도 일면 상에 무기물 입자 및 바인더 고분자의 혼합물을 포함하는 다공성 코팅층이 더 구비될 수 있다. 특히, 리튬이온 공급 코어부의 리튬이온이 외부전극에도 쉽게 전달되기 위해서는 상기 폴리에스테르, 폴리아세탈, 폴리아미드, 폴리카보네이트, 폴리이미드, 폴리에테르에테르케톤, 폴리에테르설폰, 폴리페닐렌산화물, 폴리페닐렌설파이트 및 폴리에틸렌나프탈렌으로 이루어진 군에서 선택된 고분자로 제조한 다공성 기재에 해당하는 부직포 재질의 세퍼레이터를 사용하는 것이 바람직하다.The separator is not limited to the type, but is made of a polyolefin-based polymer selected from the group consisting of ethylene homopolymer, propylene homopolymer, ethylene-butene copolymer, ethylene-hexene copolymer and ethylene-methacrylate copolymer. materials; A porous substrate made of a polymer selected from the group consisting of polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyether sulfone, polyphenylene oxide, polyphenylene sulfite and polyethylene naphthalene; Alternatively, a porous substrate formed of a mixture of inorganic particles and a binder polymer may be used. Further, as the separator, a porous coating layer including a mixture of inorganic particles and a binder polymer may be further provided on at least one surface of the porous substrate made of the above-described polymer. In particular, in order for lithium ions to be supplied to the lithium ion supply core part easily to the external electrode, the polyester, polyacetal, polyamide, polycarbonate, polyimide, polyether ether ketone, polyether sulfone, polyphenylene oxide, polyphenylene sulfide It is preferable to use a separator made of a non-woven material corresponding to a porous substrate made of a polymer selected from the group consisting of pits and polyethylene naphthalene.
또한, 본 발명의 일 측면에 따른 플렉서블 이차전지의 제조방법은, (S1) 내부전극, 상기 내부전극을 둘러싸며 형성된 전극의 단락을 방지하는 분리층 및 상기 분리층의 외면을 둘러싸며 형성된 외부전극을 포함하는 소정 형상의 수평 단면을 가지고 길이 방향으로 연장된 전극조립체를 준비하는 단계;In addition, the method of manufacturing a flexible secondary battery according to an aspect of the present invention includes: (S1) an internal electrode, a separation layer preventing a short circuit of the electrode formed surrounding the internal electrode, and an external electrode formed surrounding the outer surface of the separation layer. Preparing an electrode assembly having a horizontal cross-section having a predetermined shape and extending in a longitudinal direction;
(S2) 본 발명에 따른 전술한 수분 차단 필름을 상기 전극조립체의 외면 둘레보다 더 긴 길이로 준비하는 단계;(S2) preparing the aforementioned moisture barrier film according to the present invention to a length longer than the outer circumference of the electrode assembly;
(S3) 상기 수분 차단 필름의 양쪽 단부가 서로 겹쳐지도록 또는 상기 수분 차단 필름의 한쪽 단부의 일면의 제1 실란트층이 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹치도록 상기 전극조립체의 전체 외면을 상기 수분 차단 필름으로 둘러싸고 상기 실란트층을 열압착하는 단계; (S3) The entire assembly of the electrode assembly such that both ends of the moisture barrier film overlap each other or a first sealant layer on one side of one end of the moisture barrier film overlaps each other on a second portion of the second sealant layer on the other end. Surrounding the outer surface with the moisture barrier film and thermocompressing the sealant layer;
(S4) 상기 수분 차단 필름이 둘러싸여진 전극조립체를 가열 및/또는 가압하여, 상기 플렉서블 이차전지용 패키징의 실란트층의 겹쳐진 부분을 실링시키는 단계; 및(S4) heating and / or pressing the electrode assembly surrounded by the moisture barrier film to seal the overlapped portion of the sealant layer of the flexible secondary battery packaging; And
(S5) 상기 수분 차단 필름으로 둘러싸인 전극조립체를 열수축 튜브에 삽입한 후에 가열하여, 상기 플렉서블 이차전지용 패키징을 전극조립체에 접합시키는 단계;를 포함한다.(S5) bonding the flexible secondary battery packaging to the electrode assembly by heating after inserting the electrode assembly surrounded by the moisture barrier film into the heat shrink tube.
이와 같이 본 발명의 일 실시예에 따른 플렉서블 이차전지는 전극조립체를 표면 밀착하게(skin-tight) 패키징이 적용되어 구겨짐이 없고, 그로 인해 전지의 유연성이 개선될 수 있다. 또한, 상기 패키징에 열수축 튜브가 포함됨으로써 더 우수한 전지 유연성을 나타낼 수 있다.In this way, the flexible secondary battery according to an embodiment of the present invention has no wrinkle due to skin-tight packaging of the electrode assembly, thereby improving the flexibility of the battery. In addition, by including a heat-shrinkable tube in the packaging can exhibit better battery flexibility.
이하, 본 발명을 구체적으로 설명하기 위해 실시예를 들어 상세하게 설명하기로 한다. 그러나, 본 발명에 따른 실시예는 여러 가지 다른 형태로 변형될 수 있으며, 본 발명의 범위가 아래에서 상술하는 실시예에 한정되는 것으로 해석되어서는 아니 된다. 본 발명의 실시예는 당업계에서 평균적인 지식을 가진 자에게 본 발명을 보다 완전하게 설명하기 위해서 제공되는 것이다.Hereinafter, examples will be described in detail to specifically describe the present invention. However, the embodiments according to the present invention can be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.
실시예 1Example 1
실란트층으로 폴리프로필렌 필름(율촌화학) 을 준비하였다.A polypropylene film (Yulchon Chemical) was prepared as a sealant layer.
환원 그래핀 옥사이드층을 제작하기 위해, 그래핀 옥사이드 입자(graphene oxide powder, Standard Graphen 社)를 탈이온수에 넣고, 초음파 분산기로 에너지를 가하여 1 mg/mL 농도의 그래핀 옥사이드 분산조성물을 준비하였다. 이어서, 상기 분산조성물에, 금속염인 CuCl 2 (Sigma Aldrich 社, CuCl 2)을 그래핀 옥사이드 입자의 중량에 대해 1 중량%의 양으로 첨가하였다. 상기 폴리프로필렌 필름 위에 상기 분산 조성물을 부은 후에, 바 코팅(bar coating)으로 코팅한 후에 건조시켜 그래핀 옥사이드층을 제조하였다. 제조된 그래핀 옥사이드층을 90 ℃의 요오드산 용액 (TCI 社, 57% Hydriodic acid)에 함침시키고 12시간 이상 유지시켰다. 형성된 환원 그래핀 옥사이드층을 증류수로 세척하고 상온에서 건조시켰다. 상기 환원 그래핀 옥사이드층에 포함된 환원 그래핀 옥사이드층의 환원 그래핀 옥사이드 시트는 약 0.3 내지 0.4 nm의 인터레이터 간격을 가졌으며, 상기 환원 그래핀 옥사이드층은 약 100 nm의 두께를 가졌고, 상기 층을 구성하는 그래핀 옥사이드 시트는 1 내지 4 nm의 두께를 갖는 것으로 확인되었다. In order to prepare a reduced graphene oxide layer, graphene oxide particles (graphene oxide powder, Standard Graphen Co.) were placed in deionized water, and energy was added with an ultrasonic disperser to prepare a graphene oxide dispersion composition having a concentration of 1 mg / mL. Subsequently, to the dispersion composition, metal salt CuCl 2 (Sigma Aldrich, CuCl 2 ) was added in an amount of 1% by weight based on the weight of the graphene oxide particles. After the dispersion composition was poured on the polypropylene film, a coating was performed with a bar coating, followed by drying to prepare a graphene oxide layer. The prepared graphene oxide layer was immersed in a solution of iodic acid at 90 ° C (TCI, 57% Hydriodic acid) and maintained for at least 12 hours. The formed reduced graphene oxide layer was washed with distilled water and dried at room temperature. The reduced graphene oxide sheet of the reduced graphene oxide layer included in the reduced graphene oxide layer had an interulator spacing of about 0.3 to 0.4 nm, and the reduced graphene oxide layer had a thickness of about 100 nm, and The graphene oxide sheet constituting the layer was found to have a thickness of 1 to 4 nm.
환원 그래핀 옥사이드 시트의 인터레이어 간격은 XRD 장치를 사용하여 측정하고 Brag equation 으로 계산하여 산출하였다. 상기 XRD 장치로는 Bruker 사의 D4 Endeavor를 사용하였다.The interlayer spacing of the reduced graphene oxide sheet was measured using an XRD device and calculated using the Brag equation. As the XRD device, D4 Endeavor from Bruker was used.
환원 그래핀 옥사이드층의 두께는, 합성된 환원 그래핀 옥사이드층의 단면을 SEM 장치로 관찰하여 결정하였으며, 상기 SEM 장치로는 Hitachi 4800을 사용하였다.The thickness of the reduced graphene oxide layer was determined by observing the cross section of the synthesized reduced graphene oxide layer with an SEM device, and Hitachi 4800 was used as the SEM device.
또한, 환원 그래핀 옥사이드 시트의 두께는, 환원 그래핀 옥사이드 시트를 SiO 2 기판 위에 스핀-캐스팅(spin-casting)한 후에 Atomic Force Microscope (AFM) 장치를 사용하여 측정하였으며, 상기 AFM 장치로는 Park Systems사의 NX10을 사용하였다. In addition, the thickness of the reduced graphene oxide sheet was measured using an atomic force microscope (AFM) device after spin-casting the reduced graphene oxide sheet onto an SiO 2 substrate. Systems NX10 was used.
음극의 제조Preparation of cathode
음극활물질로 인조흑연, 도전재로 덴카블랙(carbon black), 바인더로 폴리비닐리덴 플루오라이드(PVdF)를 각각 75:5:25의 중량비로 혼합하고, 용매인 N-메틸피롤리돈(NMP)을 첨가하여 음극 슬러리를 제조하였다. Artificial graphite as a negative electrode active material, carbon black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder are mixed in a weight ratio of 75: 5: 25, respectively, and N-methylpyrrolidone (NMP) as a solvent. Was added to prepare a negative electrode slurry.
상기 음극 슬러리를 3.8 mAh/cm 2의 로딩량으로 250 ㎛ 직경의 와이어 형상의 구리 집전체에 코팅 및 건조하여 음극 활물질층이 형성된 와이어형 음극을 준비하였다. 준비된 와이어형 음극 4개를 권선하여 스프링 형태로 제작하여, 내부가 비어 있고 리튬 이온 공급 코어부가 존재하는 열린 구조의 내부 음극부를 형성하였다. 상기 내부 음극부 타측에 폴리올레핀 필름 세퍼레이터를 권선하여 분리층을 형성시켰다. The negative electrode slurry was coated and dried on a wire-shaped copper current collector having a diameter of 250 μm with a loading of 3.8 mAh / cm 2 to prepare a wire-type negative electrode having a negative electrode active material layer. The four prepared wire-type negative electrodes were wound to produce a spring, thereby forming an internal negative electrode part of an open structure with an empty interior and a lithium ion supply core. A separation layer was formed by winding a polyolefin film separator on the other side of the internal cathode.
양극의 제조Preparation of anode
양극 활물질로서 LiCoO 2, 도전재로 덴카 블랙 및 바인더로 폴리비닐리덴 플루오라이드(PVdF)를 85:5:15의 중량비로 용매인 N-메틸피롤리돈(NMP)에 첨가하여, 양극활물질 슬러리를 준비하였다. 상기 양극활물질 슬러리를 시트 형상의 알루미늄 집전체 위에 코팅하고 건조시켜서 양극 활물질층을 형성하였다. 도전재인 카본 블랙과 PVdF 바인더를 1:1 중량비로 NMP 용매에 분산시켜 도전층 슬러리를 준비하였다. 상기 양극 활물질층 위에 도전층 슬러리를 도포하고, 상기 도전층 슬러리 위에 다공성 폴리머 부직포 기재 위치시킨 후에 상기 도전층 슬러리를 건조시켜 시트형 외부 양극을 준비하였다. 이 때, 제조된 양극은 음극 방전 용량 대비 N/P ratio를 108%로 설계하여 준비하였다 (최종 양극 로딩양: 3.3 mAh/cm 2). 상기 시트형 외부 양극을 폭이 2 mm가 되게 자른 후에, 내부 음극 및 분리층의 주변에 권선하여 전극조립체를 제작하였다.LiCoO 2 as a positive electrode active material, Denka Black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder were added to N-methylpyrrolidone (NMP) as a solvent at a weight ratio of 85: 5: 15 to prepare a positive electrode active material slurry. I prepared. The positive electrode active material slurry was coated on a sheet-shaped aluminum current collector and dried to form a positive electrode active material layer. Conductive layer slurry was prepared by dispersing carbon black, which is a conductive material, and PVdF binder in a NMP solvent in a 1: 1 weight ratio. A conductive layer slurry was applied on the positive electrode active material layer, and after placing the porous polymer nonwoven fabric substrate on the conductive layer slurry, the conductive layer slurry was dried to prepare a sheet-like external positive electrode. At this time, the prepared positive electrode was prepared by designing the N / P ratio to 108% compared to the negative electrode discharge capacity (final positive electrode loading amount: 3.3 mAh / cm 2 ). After cutting the sheet-like outer anode to have a width of 2 mm, an electrode assembly was manufactured by winding around the inner cathode and the separation layer.
플렉서블 이차전지용 패키징의 적용Application of packaging for flexible secondary batteries
상기에서 제작된 수분 차단 필름이 상기와 같이 제작된 전극조립체의 외면을 감싸면서 소정 부분이 겹치도록 하고, 이 때, 전극조립체의 외면은 실란트층과 접하도록 하였다. 또한, 수분 차단 필름에 의해 감싸진 전극조립체의 외곽에 열수축 튜브(율촌 화학, 개질된 폴리비닐리덴 플루오라이드 튜브)가 존재하도록 한 후에 열을 가하여 상기 열수축 튜브를 수축시켰다. 이어서, 열린 구조의 내부 전극 지지체 중심부에 비수전해액 (1M LiPF 6, 에틸렌 카보네이트(EC)/프로필렌 카보네이트(PC)/디에틸 카보네이트(DEC))을 주사기를 이용하여 주입하여 리튬이온 공급 코어부를 형성한 후에 열을 가하였다. 이로써, 전극조립체의 외면을 플렉서블 이차전지용 패키징이 완전히 밀봉하게 되었다.The moisture barrier film produced above encloses the outer surface of the electrode assembly manufactured as described above so that a predetermined portion overlaps, and at this time, the outer surface of the electrode assembly is in contact with the sealant layer. In addition, after the heat shrink tube (Yulchon Chemical, a modified polyvinylidene fluoride tube) was present on the outside of the electrode assembly wrapped by the moisture barrier film, heat was applied to shrink the heat shrink tube. Subsequently, a non-aqueous electrolyte solution (1M LiPF 6 , ethylene carbonate (EC) / propylene carbonate (PC) / diethyl carbonate (DEC)) was injected into the center of the internal electrode support in an open structure using a syringe to form a lithium ion supply core. Heat was later applied. Thus, the packaging for the flexible secondary battery was completely sealed on the outer surface of the electrode assembly.
그 결과, 수분 차단 필름 및 열수축 튜브로 이루어진 플렉서블 이차전지용 패키징과, 이러한 플렉서블 이차전지용 패키징이 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 관 형태를 이루고 있는 플렉서블 이차전지를 모두 수득하였다. As a result, a flexible secondary battery packaging composed of a moisture barrier film and a heat-shrinkable tube, and a flexible secondary battery packaging such that the flexible secondary battery packaging formed a tube surrounding the outer surface of the flexible secondary battery electrode assembly were obtained.
실시예 2Example 2
실시예 1에서 제작된 폴리프로필렌 필름(제1 실란트층에 해당)이 일면에 형성된 환원 그래핀 옥사이드층 외곽에 제2 실란트층을 더 형성시키기 위해, 바코팅 방법에 의해 환원 그래핀 옥사이드층 외곽에 폴리프로필렌 필름(율촌화학)을 적용시켰다. 이로써, 제1 실란트층인 폴리프로필렌 필름, 환원 그래핀 옥사이드층, 제2 실란트층인 폴리프로필렌 필름으로 구성된 수분 차단 필름을 수득하였다.In order to further form a second sealant layer on the outer side of the reduced graphene oxide layer formed on one surface of the polypropylene film (corresponding to the first sealant layer) prepared in Example 1, on the outer side of the reduced graphene oxide layer by a bar coating method Polypropylene film (Yulchon Chemical) was applied. Thus, a moisture barrier film composed of a polypropylene film as a first sealant layer, a reduced graphene oxide layer, and a polypropylene film as a second sealant layer was obtained.
그 외는 실시예 1과 동일한 방법으로 상기 수분 차단 필름 및 열수축 튜브로 이루어진 플렉서블 이차전지용 패키징과, 이러한 플렉서블 이차전지용 패키징이 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 관 형태를 이루고 있는 플렉서블 이차전지를 모두 수득하였다. In the same manner as in Example 1, all of the flexible secondary battery packaging made of the moisture barrier film and the heat-shrinkable tube, and the flexible secondary battery packaging are all flexible secondary batteries having a tube shape surrounding the outer surface of the flexible secondary battery electrode assembly. Obtained.
비교예 1Comparative Example 1
CuCl 2을 분산조성물에 투입하지 않은 것을 제외하고 실시예 1과 동일한 방법으로 수분 차단 필름을 수득하였다. 제조된 수분 차단 필름에 있는 환원 그래핀 옥사이드층의 환원 그래핀 옥사이드 시트는 약 0.3 내지 0.4 nm의 인터레이어 간격을 가졌으며, 상기 환원 그래핀 옥사이드층은 약 100 nm의 두께를 가졌고, 상기 그래핀 옥사이드 시트는 1 내지 4 nm의 두께를 갖는 것으로 확인되었다. A water barrier film was obtained in the same manner as in Example 1, except that CuCl 2 was not added to the dispersion composition. The reduced graphene oxide sheet of the reduced graphene oxide layer in the prepared moisture barrier film had an interlayer spacing of about 0.3 to 0.4 nm, and the reduced graphene oxide layer had a thickness of about 100 nm, and the graphene The oxide sheet was found to have a thickness of 1 to 4 nm.
그 외는 실시예 1과 동일한 방법으로 상기 수분 차단 필름 및 열수축 튜브로 이루어진 플렉서블 이차전지용 패키징과, 이러한 플렉서블 이차전지용 패키징이 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 관 형태를 이루고 있는 플렉서블 이차전지를 모두 수득하였다. In the same manner as in Example 1, all of the flexible secondary battery packaging made of the moisture barrier film and the heat-shrinkable tube, and the flexible secondary battery packaging are all flexible secondary batteries having a tube shape surrounding the outer surface of the flexible secondary battery electrode assembly. Obtained.
비교예 2Comparative Example 2
폴리에틸렌 테레프탈레이트(PET) 필름(㈜라미에이스, 라미네이팅 필름)을 준비하였다.A polyethylene terephthalate (PET) film (Rami Ace, Laminating Film) was prepared.
그 외는 실시예 1과 동일한 방법으로 상기 폴리에틸렌 테레프탈레이트(PET) 필름 및 열수축 튜브로 이루어진 플렉서블 이차전지용 패키징과, 이러한 플렉서블 이차전지용 패키징이 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 관 형태를 이루고 있는 플렉서블 이차전지를 모두 수득하였다. Other than that, the packaging for the flexible secondary battery made of the polyethylene terephthalate (PET) film and the heat-shrinkable tube in the same manner as in Example 1, and the packaging for the flexible secondary battery forming a tube that surrounds the outer surface of the flexible secondary battery electrode assembly All secondary batteries were obtained.
비교예 3Comparative Example 3
폴리에틸렌 테레프탈레이트(PET) 필름(㈜라미에이스, 라미네이팅 필름)의 양면에, 실란트층인 폴리프로필렌 필름을 바코팅 방법에 의해 적용시켜 수분 차단 필름을 준비하였다.A moisture barrier film was prepared by applying a polypropylene film, a sealant layer, by a bar coating method to both sides of a polyethylene terephthalate (PET) film (Ramiace Co., Ltd., a laminating film).
그 외는 실시예 1과 동일한 방법으로 상기 수분 차단 필름 및 열수축 튜브로 이루어진 플렉서블 이차전지용 패키징과, 이러한 플렉서블 이차전지용 패키징이 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 관 형태를 이루고 있는 플렉서블 이차전지를 모두 수득하였다. In the same manner as in Example 1, all of the flexible secondary battery packaging made of the moisture barrier film and the heat-shrinkable tube, and the flexible secondary battery packaging are all flexible secondary batteries having a tube shape surrounding the outer surface of the flexible secondary battery electrode assembly. Obtained.
평가 1: 수분 차단 특성의 측정Evaluation 1: Measurement of moisture barrier properties
수분 차단 특성을 측정하기 위해, 실시예 1 및 비교예 1과 비교예 2에서 제조된 각각의 수분 차단 필름을 10 x 10 cm 크기로 준비하였고, 재단한 후, 투습도 시험기(제조사: ㈜ 세진시험기술, 모델명: SJTM-014)의 내부에 각각 장착하였다. 그런 다음, 플렉시블 이차전지용 패키징 일면 측에는 수증기가 포함되지 않은 건조한 질소 가스를 유입시키고, 타면 측에는 수증기를 유입시켰다. 이 때, 플렉시블 이차전지용 패키징의 양 면에 유입되는 가스가 혼합되지 않도록 상기 가스들이 각각 유입되는 두 공간을 서로 격리시켰다. 한편, 실험을 하는 동안 온도는 38 ℃, 상기 습도는 100 %RH로 설정하고 유지하였다. 그리고 24 시간 동안, 습도 센서를 이용하여 건조한 질소 가스를 유입한 상기 일면에서 수증기의 양을 측정하였다. 이러한 수증기의 양을 상기 일면의 면적으로 나누어, 24 시간 동안 파우치 필름을 투과한 단위 면적당 수증기의 양을 도출하고, 이를 투습도(WVRT)로 평가하였다. 그 결과를 표 1에 나타내었다.In order to measure the moisture barrier properties, each of the moisture barrier films prepared in Example 1 and Comparative Examples 1 and 2 were prepared in a size of 10 x 10 cm, and after being cut, a moisture permeability tester (manufacturer: Sejin Test Technology Co., Ltd.) , Model name: SJTM-014), respectively. Then, dry nitrogen gas containing no water vapor was introduced into one side of the packaging for the flexible secondary battery, and water vapor was introduced into the other side. At this time, the two spaces into which the respective gases were introduced were separated from each other so that the gases flowing into both sides of the packaging for the flexible secondary battery did not mix. On the other hand, during the experiment, the temperature was set at 38 ° C. and the humidity was maintained at 100% RH. Then, for 24 hours, a moisture sensor was used to measure the amount of water vapor on the surface of the dry nitrogen gas. The amount of water vapor was divided by the area of the one surface to derive the amount of water vapor per unit area that permeated the pouch film for 24 hours, and this was evaluated by moisture permeability (WVRT). Table 1 shows the results.
그 결과, 하기 표 1에 기재된 바와 같이, 실시예 1의 수분 차단 필름의 수증기 투과속도가 비교예 1 및 비교예 2 각각의 이차전지용 패키징 필름에 비해 현저하게 개선된 것으로 확인되었다. 이를 통해, 환원 그래핀 옥사이드층을 구성하는 환원 그래핀 옥사이드 시트가 정전기적 상호작용을 형성하는 이차전지용 패키징 필름이, 상기 정전기적 상호작용이 없는 이차전지용 패키징 필름에 비해 수분을 효과적으로 차단할 수 있음을 확인할 수 있었다.  As a result, as shown in Table 1 below, it was confirmed that the water vapor transmission rate of the moisture barrier film of Example 1 was significantly improved compared to the packaging film for secondary batteries of Comparative Examples 1 and 2, respectively. Through this, the packaging film for secondary batteries in which the reduced graphene oxide sheet constituting the reducing graphene oxide layer forms an electrostatic interaction can effectively block moisture compared to the packaging film for secondary batteries without the electrostatic interaction. I could confirm.
실시예 1Example 1 비교예 1Comparative Example 1 비교예 2Comparative Example 2
WVTR (g/m 2/day)WVTR (g / m 2 / day) 9.2 x 10 -3 9.2 x 10 -3 1.38 x 10 -1 1.38 x 10 -1 3.03.0
평가 2: 전지 성능의 측정Evaluation 2: Measurement of battery performance
실시예 2 및 비교예 3 각각에서 제작된 플렉서블 이차전지에 대하여 0.3 C의 전류 밀도로 2.5 V 내지 4.2 V의 전압 조건에서 충방전 실험을 진행하고, 그 결과를 도 9에 도시하였다. 도 9에서 확인되는 바와 같이, 비교예 3에서 제작된 플렉서블 이차전지는 10회 사이클 이전에 용량이 현저하게 감소하는 반면, 실시예 2에서 제작된 플렉서블 이차전지는 지속적으로 우수한 용량을 나타내는 것으로 확인되었다. For the flexible secondary battery manufactured in each of Example 2 and Comparative Example 3, charging and discharging experiments were performed under a voltage condition of 2.5 V to 4.2 V with a current density of 0.3 C, and the results are shown in FIG. 9. As can be seen in Figure 9, the flexible secondary battery produced in Comparative Example 3 was significantly reduced in capacity before 10 cycles, while the flexible secondary battery produced in Example 2 was confirmed to continuously exhibit excellent capacity. .

Claims (15)

  1. 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징에 있어서, In the packaging for a flexible secondary battery surrounding the outer surface of the flexible secondary battery electrode assembly,
    상기 플렉서블 이차전지용 패키징은 상기 전극조립체의 외면을 둘러싸는 관 형태이고, The packaging for the flexible secondary battery is in the form of a tube surrounding the outer surface of the electrode assembly,
    상기 플렉서블 이차전지용 패키징은, 복수 개의 환원 그래핀 옥사이드 시트를 포함하는 환원 그래핀 옥사이드(reduced Graphene Oxide (rGO))층과 상기 환원 그래핀 옥사이드의 일측 및 타측 중 어느 하나 이상에 위치하는 실란트층을 포함하는 수분 차단 필름; 및 상기 수분 차단 필름의 최외측을 둘러싸는 고분자 열수축 튜브;를 포함하고, The flexible secondary battery packaging includes a reduced graphene oxide (rGO) layer including a plurality of reduced graphene oxide sheets and a sealant layer positioned on at least one of the one side and the other side of the reduced graphene oxide. Moisture barrier film containing; And a polymer heat-shrinkable tube surrounding the outermost side of the moisture barrier film.
    상기 환원 그래핀 옥사이드층에서 상기 복수 개의 환원 그래핀 옥사이드 시트는 서로 인접한 환원 그래핀 옥사이드 시트 사이에 정전기적 상호작용을 형성하고 있는 것을 특징으로 하는In the reduced graphene oxide layer, the plurality of reduced graphene oxide sheets form electrostatic interactions between the reduced graphene oxide sheets adjacent to each other.
    플렉서블 이차전지용 패키징.Packaging for flexible secondary batteries.
  2. 제1항에 있어서, According to claim 1,
    상기 환원 그래핀 옥사이드 시트는 환원 그래핀 옥사이드 입자 1 내지 3개의 층구조를 갖는 것을 특징으로 하는 플렉서블 이차전지용 패키징.The reduced graphene oxide sheet is a flexible secondary battery packaging, characterized in that it has a layer structure of 1 to 3 reduced graphene oxide particles.
  3. 제1항에 있어서, According to claim 1,
    상기 환원 그래핀 옥사이드 시트는 0.002 내지 10 ㎛ 범위의 두께를 갖는 것을 특징으로 하는 플렉서블 이차전지용 패키징.The reduced graphene oxide sheet is a flexible secondary battery packaging, characterized in that having a thickness in the range of 0.002 to 10 ㎛.
  4. 제1항에 있어서, According to claim 1,
    상기 환원 그래핀 옥사이드 시트는 Li +, K +, Ag +, Mg 2 +, Ca 2 +, Cu 2 +, Pb 2 +, Co 2 +, Al 3 +, Cr 3+, Fe 3 + 또는 이들 2 이상에 의해 인접 환원 그래핀 옥사이드 시트와 정전기적 상호작용을 형성하는 것을 특징으로 하는 플렉서블 이차전지용 패키징.The reduced graphene oxide sheet is Li + , K + , Ag + , Mg 2 + , Ca 2 + , Cu 2 + , Pb 2 + , Co 2 + , Al 3 + , Cr 3+ , Fe 3 + or these 2 Packaging for a flexible secondary battery, characterized in that to form an electrostatic interaction with the adjacent reduced graphene oxide sheet by the above.
  5. 제1항에 있어서, According to claim 1,
    상기 수분 차단 필름은, 상기 환원 그래핀 옥사이드의 일측에 위치하는 실란트층을 포함하고,The moisture barrier film includes a sealant layer located on one side of the reduced graphene oxide,
    상기 환원 그래핀 옥사이드층의 타측에 위치하는 기계적 지지층을 더 포함하고, Further comprising a mechanical support layer located on the other side of the reduced graphene oxide layer,
    양 단부가 겹쳐진 형태로 상기 전극조립체의 외면을 둘러싸는 관형태를 이루고, Forming a tube that surrounds the outer surface of the electrode assembly in the form of overlapping both ends,
    상기 수분 차단 필름의 서로 겹쳐진 양 단부의 대향하는 실란트층이 열압착되어 실링부를 이루고, The opposing sealant layers of both ends overlapping each other of the moisture barrier film are thermocompressed to form a sealing portion,
    상기 실링부가 상기 수분 차단 필름의 둘레를 따라 폴딩된 날개부를 형성하는 것을 특징으로 하는 Characterized in that the sealing portion forms a folded wing portion along the periphery of the moisture barrier film.
    플렉서블 이차전지용 패키징.Packaging for flexible secondary batteries.
  6. 제5항에 있어서,The method of claim 5,
    상기 기계적 지지층과 상기 환원 그래핀 옥사이드층 사이, 및 상기 환원 그래핀 옥사이드층과 상기 실란트층 사이 중 적어도 하나 이상에 접착층을 더 포함하는 것을 특징으로 하는 플렉서블 이차전지용 패키징.Packaging of a flexible secondary battery further comprises an adhesive layer between at least one of the mechanical support layer and the reduced graphene oxide layer, and between the reduced graphene oxide layer and the sealant layer.
  7. 제1항에 있어서, According to claim 1,
    상기 수분 차단 필름은, 상기 환원 그래핀 옥사이드층의 일측 및 타측 모두에 위치하는 2개의 실란트층을 포함하고,The moisture barrier film includes two sealant layers located on one side and the other side of the reduced graphene oxide layer,
    상기 2개의 실란트층은 상기 환원 그래핀 옥사이드층의 일측에 위치하는 제1 실란트층과 상기 환원 그래핀 옥사이드층의 타측에 위치하는 제2 실란트층이고, The two sealant layers are a first sealant layer located on one side of the reduced graphene oxide layer and a second sealant layer located on the other side of the reduced graphene oxide layer,
    상기 수분 차단 필름의 한쪽 단부 일면의 제1 실란트층과 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹쳐서 접착되어 있는 것을 특징으로 하는It characterized in that the first sealant layer on one side of the moisture barrier film and the second sealant layer on the other side of the other end overlap and adhere to each other at a predetermined portion.
    플렉서블 이차전지용 패키징.Packaging for flexible secondary batteries.
  8. 제7항에 있어서,The method of claim 7,
    상기 환원 그래핀 옥사이드층과 상기 제2 실란트층 사이에 기계적 지지층을 더 포함하는 것을 특징으로 하는 플렉서블 이차전지용 패키징.Packaging for a flexible secondary battery further comprising a mechanical support layer between the reduced graphene oxide layer and the second sealant layer.
  9. 제7항에 있어서,The method of claim 7,
    상기 환원 그래핀 옥사이드층과 상기 제1 실란트층 사이, 상기 환원 그래핀 옥사이드층과 상기 제2 실란트층 사이, 상기 기계적 지지층과 상기 제2 실란트층 사이 중 적어도 하나 이상에 접착층을 더 포함하는 것을 특징으로 하는 플렉서블 이차전지용 패키징.It characterized in that it further comprises an adhesive layer between the reduced graphene oxide layer and the first sealant layer, between the reduced graphene oxide layer and the second sealant layer, between the mechanical support layer and the second sealant layer. Flexible secondary battery packaging.
  10. 제1항에 있어서,According to claim 1,
    상기 환원 그래핀 옥사이드층이 20 nm 내지 30 ㎛ 범위의 두께를 가지는 것을 특징으로 하는 플렉서블 이차전지용 패키징.Packaging of a flexible secondary battery, characterized in that the reduced graphene oxide layer has a thickness in the range of 20 nm to 30 μm.
  11. 제1항에 있어서,According to claim 1,
    상기 환원 그래핀 옥사이드층이 0.3 nm 내지 5.0 nm 범위의 인터레이어(interlayer) 간격을 갖는 것을 특징으로 하는 플렉서블 이차전지용 패키징.Packaging of a flexible secondary battery, characterized in that the reduced graphene oxide layer has an interlayer spacing in the range of 0.3 nm to 5.0 nm.
  12. 플렉서블 이차전지 전극조립체의 외면을 둘러싸는 플렉서블 이차전지용 패키징의 제조방법으로서,A method of manufacturing a packaging for a flexible secondary battery surrounding the outer surface of the flexible secondary battery electrode assembly,
    실란트층을 준비하는 단계;Preparing a sealant layer;
    그래핀 옥사이드(Graphene Oxide (GO)) 입자와 금속염이 분산되어 있는 분산조성물을 상기 실란트층 상에 코팅 및 건조하여, 환원된 그래핀 옥사이드 층(reduced Graphene Oxide (rGO))을 형성시켜서, 상기 실란트층의 일면에 환원된 그래핀 옥사이드층이 형성되어 있는 수분 차단 필름을 형성하는 단계;Graphene oxide (Graphene Oxide (GO)) coated with a dispersion composition in which particles and metal salts are dispersed and dried on the sealant layer to form a reduced graphene oxide (rGO), the sealant Forming a moisture barrier film having a reduced graphene oxide layer formed on one surface of the layer;
    상기 수분 차단 필름으로 상기 플렉서블 이차전지 전극조립체의 외면을 감싸도록 하는 단계; 및Covering the outer surface of the flexible secondary battery electrode assembly with the moisture barrier film; And
    상기 수분 차단 필름에 의해 외면이 감싸진 전극조립체의 외곽에 열수축 튜브가 존재하도록 한 후에 상기 열수축 튜브를 수축시키는 단계;Shrinking the heat-shrinkable tube after allowing the heat-shrinkable tube to exist on the outside of the electrode assembly whose outer surface is covered by the moisture barrier film;
    를 포함하는 것을 특징으로 하는 제1항에 기재된 플렉서블 이차전지용 패키징의 제조방법.The manufacturing method of the flexible secondary battery packaging according to claim 1 comprising a.
  13. 제12항에 있어서,The method of claim 12,
    상기 그래핀 옥사이드층이 요오드산 또는 비타민 C에 의해 환원되는 것인 플렉서블 이차전지용 패키징의 제조방법.Method for manufacturing a flexible secondary battery packaging wherein the graphene oxide layer is reduced by iodic acid or vitamin C.
  14. 제12항에 있어서,The method of claim 12,
    상기 수분 차단 필름은, 상기 환원 그래핀 옥사이드층의 일측 및 타측 모두에 위치하는 2개의 실란트층을 포함하고,The moisture barrier film includes two sealant layers located on one side and the other side of the reduced graphene oxide layer,
    상기 2개의 실란트층은 상기 환원 그래핀 옥사이드층의 일측에 위치하는 제1 실란트층과 상기 환원 그래핀 옥사이드층의 타측에 위치하는 제2 실란트층이고, The two sealant layers are a first sealant layer located on one side of the reduced graphene oxide layer and a second sealant layer located on the other side of the reduced graphene oxide layer,
    상기 수분 차단 필름의 한쪽 단부 일면의 제1 실란트층과 다른쪽 단부 타면의 제2 실란트층이 소정 부분 서로 겹쳐서 접착되어 있는 플렉서블 이차전지용 패키징의 제조방법.A method of manufacturing a flexible secondary battery packaging in which a first sealant layer on one surface of one end of the moisture barrier film and a second sealant layer on the other surface of the other end are overlapped and adhered to each other.
  15. 전극조립체; 상기 전극조립체의 외면을 둘러싸고 있는 제1항의 플렉서블 이차전지용 패키징;을 포함하는 플렉서블 이차전지. Electrode assembly; A flexible secondary battery comprising a; packaging for a flexible secondary battery of claim 1 surrounding the outer surface of the electrode assembly.
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KR101667205B1 (en) * 2015-04-17 2016-10-18 서울대학교산학협력단 Method for manufacturing cross-linked graphene-based film
KR20170028111A (en) * 2015-09-03 2017-03-13 주식회사 엘지화학 Cable-type secondary battery and method for manufacturing the same
KR20180057360A (en) * 2016-11-22 2018-05-30 기초과학연구원 The method for manufacturing reduced graphene oxide film

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