WO2014092473A1 - Electrode for secondary battery, secondary battery comprising same, and cable-type secondary battery - Google Patents

Electrode for secondary battery, secondary battery comprising same, and cable-type secondary battery Download PDF

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Publication number
WO2014092473A1
WO2014092473A1 PCT/KR2013/011514 KR2013011514W WO2014092473A1 WO 2014092473 A1 WO2014092473 A1 WO 2014092473A1 KR 2013011514 W KR2013011514 W KR 2013011514W WO 2014092473 A1 WO2014092473 A1 WO 2014092473A1
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Prior art keywords
current collector
active material
electrode active
coating layer
electrode
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PCT/KR2013/011514
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French (fr)
Korean (ko)
Inventor
권요한
홍장혁
정혜란
김제영
김종훈
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주식회사 엘지화학
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Application filed by 주식회사 엘지화학 filed Critical 주식회사 엘지화학
Priority to JP2014552146A priority Critical patent/JP6316207B2/en
Priority to CN201380006039.8A priority patent/CN104067418B/en
Priority claimed from KR20130154429A external-priority patent/KR101479460B1/en
Priority to US14/280,803 priority patent/US9214672B2/en
Publication of WO2014092473A1 publication Critical patent/WO2014092473A1/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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a secondary battery electrode, a secondary battery including the same, and a cable type secondary battery, and more particularly, to prevent detachment of the metal-based electrode active material layer, and to improve the energy density and cycle life characteristics, including the electrode for the secondary battery. It relates to a secondary battery and a cable type secondary battery.
  • a secondary battery is a device that converts external electrical energy into chemical energy and stores it and generates electricity when needed.
  • the term “rechargeable battery” is also used to mean that it can be charged multiple times.
  • Commonly used secondary batteries include lead storage batteries, nickel cadmium batteries (NiCd), nickel hydrogen storage 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. Examples are devices, handhelds, tools, and uninterruptible power supplies that help start up 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 kinds of conventional devices, and the demand for secondary batteries is exploding. In addition, hybrid vehicles and electric vehicles have been put to practical use in terms of prevention of environmental pollution, and these next-generation vehicles employ technologies that use secondary batteries to reduce value, weight, and extend life.
  • secondary batteries are cylindrical, rectangular or pouch type batteries. This is because the secondary battery is manufactured by mounting an electrode assembly composed of a negative electrode, a positive electrode, and a separator inside a pouch-shaped case of a cylindrical or rectangular metal can or an aluminum laminate sheet, and injecting an electrolyte into the electrode assembly. Therefore, since a certain space for mounting the secondary battery is essentially required, the cylindrical, square or pouch type of the secondary battery has a problem in that it acts as a limitation for the development of various types of portable devices. Accordingly, there is a need for a new type of secondary battery that is easily deformed.
  • a cable type secondary battery which is a battery having a very large ratio of length to cross sectional diameter.
  • desorption of the electrode active material layer may occur due to stress caused by external force or rapid volume expansion of the electrode active material layer during charge and discharge, resulting in a decrease in capacity and deterioration of cycle life characteristics.
  • a polymer binder coating layer may be further formed on the upper surface of the electrode active material layer.
  • the cycle life characteristics of the battery may be improved, but since the polymer binder coating layer has little pores therein, the electrode resistance may increase because it prevents the electrolyte from flowing into the electrode active material layer. have.
  • the reaction potential of the discharge profile is higher than that of the graphite-based electrode active material, when the full cell is manufactured and evaluated for performance, the energy density is low.
  • the problem to be solved by the present invention is to prevent the desorption phenomenon of the metal-based electrode active material layer to ensure excellent battery life characteristics, to improve the energy density, and to smoothly flow the electrolyte into the electrode active material layer of electrode resistance It is possible to prevent an increase and to provide an electrode for a secondary battery having improved electrode flexibility, a secondary battery including the same, and a cable type secondary battery.
  • a current collector In order to solve the above problems, according to an aspect of the present invention, a current collector; An electrode active material layer formed on at least one surface or an entire outer surface of the current collector; A graphite coating layer formed on an upper surface of the electrode active material layer and including graphite, a conductive material, and a first polymer binder; And a porous coating layer formed on an upper surface of the graphite coating layer and including a second polymer binder.
  • the current collector may be a planar current collector, a hollow current collector, a wire current collector, a wound wire current collector, a wound sheet current collector, or a mesh current collector.
  • the weight ratio of the graphite, the conductive material, and the first polymer binder may be 50:10:40 to 90: 1: 9.
  • the pore size formed in the graphite coating layer may be 0.1 ⁇ m to 5 ⁇ m, and the porosity may be 10 to 70%.
  • the conductive material may include any one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fiber, carbon nanotube, and graphene, or a mixture of two or more thereof.
  • the first polymer binder is polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafulopropylene (polyvinylidene fluoride-) co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile ), Polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl acetate copolymer, polyethylene oxide, polyarylate, cellulose acetate acetate), cellulose acetate butyrate, cellulose acetate Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, Any one selected from the group consisting of carboxyl
  • the size of the pores formed in the porous coating layer 0.01 ⁇ m to 10 ⁇ m, porosity may be 5 to 95%.
  • the porous coating layer may further include inorganic particles.
  • the weight ratio of the inorganic particles and the second polymer binder may be 10:90 to 95: 5.
  • the inorganic particles may be inorganic particles having a dielectric constant of 5 or more, inorganic particles having a lithium ion transfer ability, or a mixture thereof.
  • the inorganic particles having a dielectric constant of 5 or more include BaTiO 3 , Pb (Zr x , Ti 1-x ) O 3 (PZT, where 0 ⁇ x ⁇ 1), and Pb 1-x La x Zr 1-y Ti y O 3 (PLZT, where 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1), (1-x) Pb (Mg 1/3 Nb 2/3 ) O 3 -xPbTiO 3 (PMN-PT, where , 0 ⁇ x ⁇ 1), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , SiC, SiO 2 , It may be any one selected from the group consisting of AlOOH, Al (OH) 3 and TiO 2 or a mixture of two or more thereof.
  • the inorganic particles having the lithium ion transfer ability include lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li x Ti y (PO 4 ) 3 , 0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 3), lithium Aluminum Titanium Phosphate (Li x Al y Ti z (PO 4 ) 3 , 0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 3), (LiAlTiP) x O y series glass (0 ⁇ x ⁇ 4, 0 ⁇ y ⁇ 13), lithium lanthanum titanate (Li x La y TiO 3, 0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 ⁇ x ⁇ 4, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 1, 0 ⁇ w ⁇ 5), lithium nitride (Li 3 PO 4
  • the average particle diameter of the inorganic particles may be 10 nm to 5 ⁇ m.
  • the second polymer binder may be polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafuluropropylene (polyvinylidene fluoride-) co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile ), Polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl acetate copolymer, polyethylene oxide, polyarylate, cellulose acetate acetate), cellulose acetate butyrate, cellulose acetate Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, Any one selected from the group consisting of carboxyl
  • the secondary battery electrode may be a negative electrode.
  • the electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni or Fe metals (Me) ; Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
  • the negative electrode is a secondary battery electrode of the secondary battery of the present invention Is provided.
  • the lithium ion supply core portion containing an electrolyte;
  • An internal current collector having an open structure formed around an outer surface of the lithium ion supply core part, an internal electrode active material layer formed on an outer surface of the internal current collector, and an outer surface of the internal electrode active material layer, and formed of graphite, a conductive material, and a first polymer
  • An internal electrode having a graphite coating layer including a binder, and a porous coating layer formed on an outer surface of the graphite coating layer and including a second polymer binder;
  • a separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode;
  • an external electrode formed surrounding the outer surface of the separation layer, the external electrode including an external current collector and an external electrode active material layer, the cable type secondary battery having a horizontal cross section and extending in the longitudinal direction.
  • the internal current collector of the open structure may be a wound wire current collector, a wound sheet current collector, or a mesh current collector.
  • the internal electrode is a cathode, and the internal electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
  • the internal electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
  • the external electrode may include an external electrode active material layer formed to surround the outer surface of the separation layer and an external current collector formed to surround the outer surface of the external electrode active material layer, or an external house formed to surround the outer surface of the separation layer.
  • External electrode active material layer formed surrounding the outer surface of the whole and the outer current collector, or the outer current collector formed surrounding the outer surface of the separation layer and the outer surface formed to contact the separation layer surrounding the outer surface of the outer current collector
  • An external electrode active material layer provided with an electrode active material layer or surrounding the outer surface of the separation layer and covered with the outer electrode active material layer, and having an outer current collector formed while enclosing the outer surface of the separation layer with a spaced apart state; It may be.
  • the lithium ion supply core portion containing an electrolyte;
  • An inner electrode including an inner current collector having an open structure formed around an outer surface of the lithium ion supply core and an inner electrode active material layer formed on an outer surface of the inner current collector;
  • a separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode;
  • a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder.
  • the external electrode is a cathode
  • the external electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And it may include any one active material particles selected from the group consisting of oxides (MeOx) of the metals (Me) or a mixture of two or more thereof.
  • the external electrode may include a porous coating layer including a second polymer binder formed to surround the outer surface of the separation layer, and surround the outer surface of the porous coating layer and include graphite, a conductive material, and a first polymer binder.
  • An external current collector having an associated coating layer, an external electrode active material layer formed surrounding the outer surface of the graphite coating layer, and an external current collector formed surrounding the outer surface of the external electrode active material layer, or an external current collector formed surrounding the outer surface of the separation layer,
  • the outer current collector is formed to surround the outer surface of the outer current
  • a porous coating layer is formed surrounding the outer surface of the associated coating layer and the graphite coating layer, and includes a second polymer binder. It may be to.
  • the separation layer may be an electrolyte layer or a separator.
  • the electrolyte layer a gel polymer electrolyte using PEO, PVdF, PVdF-HFP, PMMA, PAN or PVAC; Or a solid electrolyte using PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES) or polyvinyl acetate (PVAc); It may be to include an electrolyte selected from.
  • the electrolyte layer may further include a lithium salt.
  • the lithium salt 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, may be one or two or more selected from lithium chloroborane, lithium lower aliphatic carbonate and lithium tetraphenyl borate.
  • the separator may include a porous polymer substrate 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;
  • a porous polymer 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 polymer substrate formed of a mixture of inorganic particles and a binder polymer 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
  • two or more lithium ion supply core portion containing an electrolyte
  • An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer;
  • a separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes;
  • an external electrode formed surrounding the outer surface of the separation layer, the external electrode including an external current collector and an external electrode active material layer, the cable type secondary battery having a horizontal cross section and extending in the longitudinal direction.
  • two or more lithium ion supply core portion containing an electrolyte
  • An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer
  • a graphite-based coating layer comprising a polymer binder, a porous coating layer formed on the outer surface of the graphite-based coating layer, and a separation layer for preventing a short circuit of the electrode formed surrounding the outer surface of the porous coating layer
  • Two or more internal electrodes disposed in parallel to each other; And an outer electrode formed to surround the outer surfaces of the inner electrodes and having an outer current collector and an outer electrode active material layer, the cable type secondary battery having a horizontal cross section and extending in the length direction.
  • two or more lithium ion supply core portion containing an electrolyte;
  • Two or more internal electrodes disposed in parallel with each other including an inner current collector having an open structure formed around an outer surface of each lithium ion supply core and an inner electrode active material layer formed surrounding the outer surface of the inner current collector;
  • a separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes;
  • a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder.
  • a cable type secondary battery having a horizontal cross section including an external electrode and extending in a length direction.
  • two or more lithium ion supply core portion containing an electrolyte;
  • An inner current collector having an open structure formed surrounding the outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed surrounding the outer surface of the inner current collector, and a short circuit of the electrode formed surrounding the outer surface of the inner electrode active material layer
  • Two or more internal electrodes disposed in parallel with each other having a separation layer for preventing;
  • a porous coating layer formed to surround the outer surfaces of the inner electrodes, the graphite-based coating layer including an outer current collector, an outer electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder.
  • a cable-type secondary battery having a horizontal cross-section including an external electrode extending in the longitudinal direction.
  • the capacity of the battery is reduced by suppressing the detachment phenomenon of the electrode active material layer, which may occur due to the stress caused by external force or the sudden volume expansion of the electrode active material layer during charging and discharging.
  • the conductivity of the electrode, and the introduction of a graphite-based coating layer exhibiting excellent battery performance can improve the initial efficiency and cycle life characteristics of the battery.
  • the performance of the battery can be improved by smoothly flowing the electrolyte into the electrode active material layer to prevent the increase of the resistance of the electrode, and by the external force such as bending and twisting, to the graphite coating layer formed on the upper surface of the electrode active material layer. Cracking or falling off can be suppressed, thereby further improving the flexibility of the electrode.
  • FIG. 1 is a view showing a perspective view of an electrode for a cable-type secondary battery including a wire-type current collector according to an embodiment of the present invention.
  • FIG. 2 is a view showing a perspective view of an electrode for a cable type secondary battery including a hollow current collector according to an embodiment of the present invention.
  • FIG 3 is a perspective view of a cable type secondary battery including one internal electrode according to an embodiment of the present invention.
  • FIG. 4 is a view showing a perspective view of a cable-type secondary battery including one internal electrode according to another embodiment of the present invention.
  • FIG. 5 is a cross-sectional view of a cable type secondary battery including two or more internal electrodes according to an embodiment of the present invention.
  • FIG. 6 is a cross-sectional view of a cable type secondary battery including two or more internal electrodes according to another embodiment of the present invention.
  • FIG. 7 is a SEM photograph showing a wire-type electrode having a graphite coating layer prepared according to an embodiment of the present invention.
  • Figure 8 is a SEM photograph showing a wire-type electrode formed with a porous coating layer prepared according to an embodiment of the present invention.
  • FIG. 9 is a graph showing normalized charging and discharging profiles for discharge capacities according to one embodiment and a comparative example of the present invention.
  • FIG. 10 is a graph showing the charge and discharge cycle life characteristics of the battery according to an embodiment and a comparative example of the present invention.
  • the current collector An electrode active material layer formed on at least one surface or an entire outer surface of the current collector; A graphite coating layer formed on an upper surface of the electrode active material layer and including graphite, a conductive material, and a first polymer binder; And a porous coating layer formed on an upper surface of the graphite coating layer and including a second polymer binder.
  • the current collector may be a planar current collector, a hollow current collector, a wire current collector, a wound wire current collector, a wound sheet current collector, or a mesh current collector, but is not limited thereto. According to the shape of the secondary battery, various kinds of current collectors are possible.
  • an electrode active material layer may be formed on at least one surface of an upper surface or a lower surface of the current collector.
  • the inside of the current collector may be formed.
  • the electrode active material layer may be formed on at least one of a surface existing in the surface and an external surface, and in the case of a wire-type current collector, the electrode active material layer may be formed on the entire surface of the current collector.
  • an electrode active material layer may be formed on at least one of a surface existing inside and a surface existing outside of the current collector. It may be formed surrounding.
  • FIG. 1 is a view showing a perspective view of an electrode for a cable type secondary battery including a wire-type current collector according to an embodiment of the present invention
  • Figure 2 includes a hollow current collector, according to an embodiment of the present invention It is a figure which shows the perspective view of the cable type secondary battery electrode.
  • an electrode 10 for a cable type secondary battery includes a wire type current collector 11; An electrode active material layer 12 formed surrounding the entire surface of the wire-shaped current collector 11; A graphite coating layer 13 formed surrounding the upper surface of the electrode active material layer 12 and including graphite, a conductive material, and a first polymer binder; And a porous coating layer 14 formed surrounding the upper surface of the graphite coating layer 13 and including a second polymer binder, and extending in the longitudinal direction.
  • the cable type secondary battery electrode 10 may include one or more wires wound in a coil shape or the like, or one or more wire composites in which two or more wires are twisted in a spiral shape are wound in a coil shape or the like to form an inside of the cable type secondary battery. Can be used as an electrode.
  • the cable-type secondary battery electrode 20 according to the present invention, the hollow current collector 21; An electrode active material layer 22 formed on a surface existing outside the hollow current collector 21; A graphite coating layer 23 formed surrounding the upper surface of the electrode active material layer 22 and including graphite, a conductive material, and a first polymer binder; And a porous coating layer 24 formed surrounding the upper surface of the graphite coating layer 23 and including a second polymer binder, and extending in the longitudinal direction.
  • the cable type secondary battery electrode 20 may be used as an external electrode of the cable type secondary battery.
  • the electrode active material layer formed on the current collector may have a detachment phenomenon of the electrode active material layer due to sudden volume expansion during charge and discharge or stress caused by external force due to deformation of the shape, or from the current collector. You can go off completely. As a result, the electrical conductivity at the electrode is poor, the capacity is not realized, the initial efficiency is low. In addition, the cycle life characteristics of the battery become very poor.
  • the metal-based negative electrode active material layer formed by a method such as electroplating or anodizing since the polymer binder and the conductive material do not exist, the detachment phenomenon may be more serious.
  • the reaction potential of the discharge profile is higher than that of the graphite electrode active material, when the full cell is manufactured, the energy density is lower than that of the graphite electrode active material.
  • a graphite coating layer made of graphite, a conductive material and a first polymer binder is formed on the outer surface of the electrode active material layer, and the porous surface made of the second polymer binder is formed on the outer surface of the graphite coating layer.
  • the graphite coating layer may serve as a buffer region that can alleviate the separation of the electrode active material layer, includes a conductive material having excellent conductivity, and the graphite coating layer itself has excellent battery characteristics. As a result, the detachment phenomenon of the electrode active material layer can be prevented and contributed to the improvement of initial efficiency and cycle life characteristics.
  • the weight ratio of the graphite, the conductive material and the first polymer binder may be 50:10:40 to 90: 1: 9.
  • pores may be formed in the graphite coating layer to enable the inflow of the electrolyte, and such pores should be smaller than the size of the particles constituting the electrode active material layer in order to suppress the detachment of the electrode active material layer, and the electrolyte may be the electrode. It is preferable that the solvation radius of the lithium ions of the electrolyte be greater than the solvating radius of the electrolyte solution to facilitate the inflow to the inlet. In order to satisfy these conditions, the pore size formed in the graphite coating layer may be 0.1 ⁇ m to 5 ⁇ m. And in order to achieve the above effect, the porosity of the graphite coating layer may be 10 to 70%.
  • the conductive material is not particularly limited as long as it is an electronic conductive material that does not cause chemical change in the secondary battery.
  • carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotubes, graphene and the like can be used, it is possible to use metal powder, conductive metal oxide, organic conductive material and the like.
  • Products currently available as conductive materials include acetylene black series (Chevron Chemical Company or Gulf Oil Company), EC series (Armak Company), Vulcan ( Vulcan), XC-72 (manufactured by Cabot Company), and Super P (manufactured by MMM).
  • the first polymer binder may include polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), and polyvinylidene fluoride-hexafuluropropylene (polyvinylidene fluoride).
  • PVDF polyvinylidene fluoride
  • HFP hexafluoro propylene
  • PVF polyvinylidene fluoride-hexafuluropropylene
  • the porous coating layer it is possible to form a porous pore structure through phase separation or phase inversion in the manufacturing process.
  • the pores formed in the porous coating layer should be smaller than the size of the particles constituting the electrode active material layer to suppress the detachment of the electrode active material layer, the electrolyte is larger than the solvation radius of lithium ions of the electrolyte in order to facilitate the inflow to the electrode It is preferable.
  • the size of the pores formed in the porous coating layer may be 0.01 ⁇ m to 10 ⁇ m.
  • the porosity of the porous coating layer may be 5 to 95%.
  • the porous coating layer may further include inorganic particles.
  • the inorganic particles of the porous coating layer are filled with each other by the second polymer binder in a state of being in contact with each other, thereby forming an interstitial volume between the inorganic particles, the inorganic particles
  • the interstitial volume between them may be empty to form pores.
  • the weight ratio of the inorganic particles and the polymer binder may be 10:90 to 95: 5 in order to secure appropriate porosity.
  • the inorganic particles that can be used in the present invention are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as the oxidation and / or reduction reactions do not occur in the operating voltage range (for example, 0 to 5 V on the basis of Li / Li + ) of the applied electrochemical device.
  • the ionic conductivity of the electrolyte may be improved by contributing to an increase in the dissociation degree of the electrolyte salt, such as lithium salt, in the liquid electrolyte.
  • the inorganic particles may include high dielectric constant inorganic particles having a dielectric constant of 5 or more, or 10 or more.
  • inorganic particles having a dielectric constant of 5 or more include BaTiO 3 , Pb (Zr x , Ti 1-x ) O 3 (PZT, where 0 ⁇ x ⁇ 1), Pb 1-x La x Zr 1- y Ti y O 3 (PLZT, where 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1), (1-x) Pb (Mg 1/3 Nb 2/3 ) O 3 -xPbTiO 3 (PMN-PT, Where 0 ⁇ x ⁇ 1), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , SiC, SiO 2 , AlOOH,
  • the inorganic particles may be used as inorganic particles having a lithium ion transfer ability, that is, inorganic particles containing a lithium element, but having a function of moving lithium ions without storing lithium.
  • inorganic particles having a lithium ion transfer capacity include lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li x Ti y (PO 4 ) 3 , 0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 3), Lithium aluminum titanium phosphate (Li x Al y Ti z (PO 4 ) 3 , 0 ⁇ x ⁇ 2, 0 ⁇ y ⁇ 1, 0 ⁇ z ⁇ 3), 14Li 2 O-9Al 2 O 3 -38TiO 2 -39P 2 (LiAlTiP) x O y series glasses such as O 5 (0 ⁇ x ⁇ 4, 0 ⁇ y ⁇ 13), lithium lanthanum titanate (Li x La y TiO 3 ,
  • the size of the inorganic particles is not limited, but for proper porosity of the porous coating layer, the average particle diameter may be 10 nm to 5 ⁇ m.
  • the second polymer binder may be polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafulopropylene (polyvinylidene fluoride-) co-hexafluoro propylene), polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone ), Polyvinylacetate, ethylene vinyl co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butylate acetate butyrate), cellulose acetate propionate, Cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose , Styrene-butadiene rubber, acrylonit
  • the current collector stainless steel, aluminum, nickel, titanium, calcined carbon, copper; Stainless steel surface-treated with carbon, nickel, titanium, or silver; Aluminum-cadmium alloys; Non-conductive polymer surface-treated with a conductive material; Or it is preferably made of a conductive polymer, the outer current collector of the open structure, stainless steel, aluminum, nickel, titanium, calcined carbon, copper; Stainless steel surface-treated with carbon, nickel, titanium, or silver; Aluminum-cadmium alloys; Non-conductive polymer surface-treated with a conductive material; Conductive polymers; A metal paste comprising a metal powder of Ni, Al, Au, Ag, Al, Pd / Ag, Cr, Ta, Cu, Ba, or ITO; Or a carbon paste containing carbon powder which is graphite, carbon black or carbon nanotubes.
  • the current collector collects electrons generated by the electrochemical reaction of the electrode active material or serves to supply electrons required for the electrochemical reaction.
  • a metal such as copper or aluminum is used.
  • it is relatively more flexible than using a metal such as copper or aluminum.
  • it is possible to achieve the light weight of the battery by using a polymer current collector in place of the metal current collector.
  • Such conductive materials may be polyacetylene, polyaniline, polypyrrole, polythiophene, polysulfuride, ITO (Indum Thin Oxide), silver, palladium and nickel, and the conductive polymer may be polyacetylene, polyaniline, polypyrrole, polythiol Offen, polysulfuritride and the like can be used.
  • the non-conductive polymer used for the current collector is not particularly limited in kind.
  • the secondary battery electrode may be a negative electrode, wherein the electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Metals (Me) which are Cu, Co, Ni or Fe; Alloys composed of the metals (Me); And an oxide (MeOx) of the metals (Me); any one active material particles selected from the group consisting of or a mixture of two or more thereof.
  • the electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Metals (Me) which are Cu, Co, Ni or Fe; Alloys composed of the metals (Me); And an oxide (MeOx) of the metals (Me); any one active material particles selected from the group consisting of or a mixture of two or more thereof.
  • 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 occlusion of ions from the electrolyte layer and release of ions into the electrolyte layer.
  • the secondary battery of the present invention includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte, the negative electrode is the secondary battery electrode of the present invention.
  • the secondary battery of the present invention may be a secondary battery of a special type such as a cable type secondary battery as well as a secondary battery of a general type of a stack type, a winding type, a stack / folding type.
  • the cable-type secondary battery having a horizontal cross section according to an aspect of the present invention extending in the longitudinal direction, the lithium ion supply core portion containing an electrolyte;
  • An internal current collector having an open structure formed around an outer surface of the lithium ion supply core part, an internal electrode active material layer formed on an outer surface of the internal current collector, and an outer surface of the internal electrode active material layer, and formed of graphite, a conductive material, and a first polymer
  • An internal electrode having a graphite coating layer including a binder, and a porous coating layer formed on an outer surface of the graphite coating layer and including a second polymer binder;
  • a separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode;
  • an external electrode formed surrounding the outer surface of the separation layer and having an external current collector and an external electrode active material layer.
  • the open structure refers to a structure in which the open structure is a boundary surface, and a structure in which material moves from inside to outside through this boundary surface is free, and the outer current collector of the open structure is a wound wire-type house. It may be a whole, a wound sheet current collector or a mesh current collector, but is not limited thereto.
  • the horizontal cross section may be circular or polygonal, which is a geometrically perfect symmetrical circular and asymmetrical oval structure.
  • the polygon is not particularly limited as long as it is not a two-dimensional sheet-like structure.
  • Non-limiting examples of the polygonal structure include triangles, squares, pentagons, and hexagons.
  • the porous coating layer may further include inorganic particles as described above.
  • the internal electrode is a cathode
  • the internal electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
  • the external electrode is a positive electrode
  • the external electrode active material layer is a positive electrode active material
  • M1 and M2 are independently from each other Al
  • Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo is any one selected from the group
  • x, y and z are independently of each other
  • An active material particle selected from the group consisting of 0 ⁇ x ⁇ 0.5, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.5, and x + y + z ⁇ 1 as an atomic fraction of oxide composition elements, or two or more thereof Mixtures may be included.
  • the cable type secondary battery of the present invention has a horizontal cross section, has a linear structure elongated in the longitudinal direction with respect to the horizontal cross section, and has flexibility, and thus deformation is free.
  • FIG 3 is a perspective view of a cable type secondary battery including one internal electrode according to an embodiment of the present invention.
  • the cable type secondary battery 100 may include a lithium ion supply core unit 110 including an electrolyte;
  • An internal current collector 120 having an open structure formed surrounding the outer surface of the lithium ion supply core unit 110, an internal electrode active material layer 130 formed on an outer surface of the internal current collector 120, and the internal electrode active material layer ( It is formed on the outer surface of 130, a graphite coating layer 131 including graphite, a conductive material and a first polymer binder, and a porous coating layer formed on the outer surface of the graphite coating layer 131, and including a second polymer binder
  • an external electrode including an external electrode active material layer 150 formed surrounding the outer surface of the separation layer 140 and an external current collector 160 formed surrounding the outer surface of the external electrode active material layer 150.
  • the external electrode may have various structures according to the positions of the external current collector and the external electrode active material layer, the external current collector formed to surround the outer surface of the separation layer and the external current formed to surround the external surface of the external current collector.
  • a structure including an outer electrode active material layer formed surrounding the outer surface of the separation layer and an outer current collector covered in the outer electrode active material layer and surrounding the outer surface of the separation layer in a spaced state; Etc. are possible.
  • the cable-type secondary battery extending in the longitudinal direction with a horizontal cross-section according to another aspect of the present invention, a lithium ion supply core portion containing an electrolyte;
  • An inner electrode including an inner current collector having an open structure formed around an outer surface of the lithium ion supply core and an inner electrode active material layer formed on an outer surface of the inner current collector;
  • a separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode;
  • a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder.
  • porous coating layer may further include inorganic particles as described above.
  • the external electrode is a negative electrode
  • the external electrode active material layer includes a negative electrode active material, as described above.
  • FIG. 4 is a diagram illustrating a perspective view of a cable type secondary battery in which a graphite-based coating layer and a porous coating layer are formed on an external electrode, according to an embodiment of the present invention.
  • the cable type secondary battery 200 may include a lithium ion supply core unit 210 including an electrolyte; An inner electrode including an inner current collector 220 having an open structure formed around the outer surface of the lithium ion supply core unit 210 and an inner electrode active material layer 230 formed on an outer surface of the inner current collector 220; A separation layer 240 surrounding the outer surface of the inner electrode to prevent a short circuit of the electrode; And a porous coating layer 252 formed around the outer surface of the separation layer 240 and surrounding the outer surface of the porous coating layer 252 including a second polymer binder, graphite, a conductive material, and a first polymer.
  • Graphite coating layer 251 including a binder, an external electrode active material layer 250 formed surrounding the outer surface of the graphite coating layer 251 and an external current collector formed surrounding the outer surface of the external electrode active material layer 250 ( It may include an external electrode having a 260.
  • the external electrode may be a variety of structures depending on the position of the conductive material coating layer and the porous coating layer, the outer current collector formed surrounding the outer surface of the separation layer, the outer formed around the outer surface of the outer current collector It is formed surrounding the outer surface of the electrode active material layer, the outer electrode active material layer, the graphite-based coating layer including graphite, a conductive material and the first polymer binder, and formed to surround the outer surface of the graphite-based coating layer, the second polymer binder A structure having a porous coating layer comprising a; An outer current collector formed to surround the outer surface of the separation layer, an outer electrode active material layer formed to contact the separation layer and surrounding the outer surface of the outer current collector, formed to surround the outer surface of the outer electrode active material layer, graphite, conductive A structure comprising a graphite coating layer comprising ash and a first polymer binder, and a porous coating layer formed surrounding the outer surface of the graphite coating layer and including a second polymer binder;
  • a structure comprising a graphite coating layer surrounding and formed surrounding the outer surface of the graphite coating layer, the graphite coating layer including graphite, a conductive material, and a first polymer binder, the porous coating layer including a second polymer binder; Etc. are possible.
  • an electrolyte layer or a separator can be used for the separation layer of this invention.
  • Examples of the electrolyte layer serving as an ion passage include a gel polymer electrolyte using PEO, PVdF, PVdF-HFP, PMMA, PAN, or PVAC; Or a solid electrolyte using PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES) or polyvinyl acetate (PVAc); Etc.
  • the matrix of the solid electrolyte is preferably made of polymer or ceramic glass as a basic skeleton.
  • ions may move very slowly in terms of reaction rate, and therefore, it is preferable to use an electrolyte of a gel polymer having easier movement of ions than a solid.
  • the gel polymer electrolyte is not excellent in mechanical properties, it may include a pore structure support or a crosslinked polymer 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 salts can improve ionic conductivity and reaction rate, non-limiting examples of which are 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 available borane lithium, lower aliphatic carboxylic acid lithium, and tetraphenyl lithium borate, etc. have.
  • the separator is not limited to a kind thereof, but a porous material 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.
  • the present invention includes a protective coating, which is formed on the outer surface of the external electrode to protect the electrode against moisture and external shock in the air as an insulator.
  • a conventional polymer resin can be used.
  • PVC, HDPE or epoxy resin can be used.
  • the cable type secondary battery according to another embodiment of the present invention includes two or more internal electrodes.
  • the internal electrode is a cathode, at least two lithium ion supply core portion containing an electrolyte;
  • An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer;
  • a separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes;
  • an external electrode formed surrounding the outer surface of the separation layer, the external electrode including an external current collector and an external electrode active material layer, or two or more lithium ion supply core parts including an electrolyte;
  • An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer
  • the porous coating layer may further include inorganic particles as described above.
  • a cable type secondary battery 300 including a plurality of internal electrodes of the present invention includes two or more lithium ion supply core portions 310 including an electrolyte;
  • An inner current collector 320 having an open structure formed around an outer surface of each of the lithium ion supply cores 310, an inner electrode active material layer 330 formed on an outer surface of the inner current collector 320, and the inner electrode active material It is formed on the outer surface of the layer 330, the graphite-based coating layer 331 including graphite, a conductive material and the first polymer binder, and formed on the outer surface of the graphite-based coating layer 331, and comprises a second polymer binder Two or more internal electrodes disposed in parallel with each other having the porous coating layer 332; A separation layer 340 surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And an external electrode including an external electrode active material layer 350 formed to surround the outer surface of the separation layer 340, and an external current collector 360 formed to surround the outer surface
  • the external electrode is a negative electrode, two or more lithium ion supply core portion containing an electrolyte; Two or more internal electrodes disposed in parallel with each other including an inner current collector having an open structure formed around an outer surface of each lithium ion supply core and an inner electrode active material layer formed surrounding the outer surface of the inner current collector; A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder.
  • An inner current collector having an open structure formed surrounding the outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed surrounding the outer surface of the inner current collector, and a short circuit of the electrode formed surrounding the outer surface of the inner electrode active material layer
  • Two or more internal electrodes disposed in parallel with each other having a separation layer for preventing;
  • a porous coating layer formed to surround the outer surfaces of the inner electrodes, the graphite-based coating layer including an outer current collector, an outer electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. It includes; an external electrode.
  • the porous coating layer may further include inorganic particles as described above.
  • At least two lithium ion supply core portions 410 including an electrolyte At least two lithium ion supply core portions 410 including an electrolyte;
  • An inner current collector 420 having an open structure formed surrounding the outer surface of each lithium ion supply core unit 410 and an inner electrode active material layer 430 formed surrounding the outer surface of the inner current collector 420.
  • Two or more internal electrodes disposed in parallel to each other;
  • a separation layer 440 which surrounds the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes;
  • a porous coating layer 452 formed surrounding the outer surface of the separation layer 440 and surrounding the outer surface of the porous coating layer 452 including a second polymer binder, graphite, a conductive material, and a first polymer.
  • Graphite coating layer 451 including a binder, an external electrode active material layer 450 formed surrounding the outer surface of the graphite coating layer 451 and an external current collector formed surrounding the outer surface of the external electrode active material layer 450 ( It includes; an external electrode having a 460.
  • the cable type secondary batteries 300 and 400 have internal electrodes formed of a plurality of electrodes, the balance between the negative electrode and the positive electrode can be easily adjusted, and the plurality of electrodes can be prevented, thereby preventing the possibility of disconnection.
  • an electrode active material containing nickel and tin having a thickness of 2.5 ⁇ m was coated on a wire-type copper current collector having a diameter of 125 ⁇ m to form an electrode active material layer.
  • a slurry was prepared by mixing a mixture of natural graphite, a conductive material, and polyvinylidene fluoride as a first polymer binder in a weight ratio of 70: 5: 25 in a solvent of N-methyl pyrrolidone.
  • the slurry was coated on the entire outer surface of the electrode active material layer to form a graphite coating layer.
  • FIG. 7 is a SEM photograph showing the shape of the wire type electrode on which the graphite coating layer is formed.
  • Figure 8 is a SEM photograph showing the shape of the porous coating layer formed by this process.
  • the wire-shaped electrode prepared in Example (1) was manufactured to be in the shape of a plate by winding on a horizontal plane, and used as a cathode, and a metal lithium foil was used as a cathode, between the anode and the cathode.
  • An electrode assembly was produced via a polyethylene separator.
  • an electrode active material containing nickel and tin having a thickness of 2.5 ⁇ m was coated on a wire-type copper current collector having a diameter of 125 ⁇ m to form an electrode active material layer.
  • a coin-type half cell was manufactured in the same manner as in Example (2) except that the wire-shaped electrode prepared in Comparative Example (1) was manufactured to be in a plate shape by winding on a horizontal plane, and then used as a negative electrode. Prepared.
  • Charge-discharge characteristics were evaluated using the coin-type half cells prepared in the examples and comparative examples.
  • the charge was kept constant at 5 mV at a constant voltage, and the charge was terminated when the current density became 0.005 C.
  • the discharge was completed in the constant current mode up to 1.5 V at a current density of 0.5 C. Charge and discharge were repeated 30 times under the same conditions.
  • the cathode discharge profile has a lower discharge reaction potential by the graphite coating layer, thereby increasing the discharge potential of the full cell to improve the energy density of the battery. have.
  • the Example is 85.8% and the comparative example showed 78.7%, and it can be seen that the Example was improved by the graphite coating layer.
  • the capacity was reduced to about 40%, while in the example, the capacity was maintained at 98% or more, which shows that the cycle life characteristics were significantly better than in the comparative example.

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Abstract

The present invention relates to an electrode for a secondary battery, a secondary battery comprising same, and a cable-type secondary battery, the electrode comprising: a current collector; an electrode active material layer formed on at least one surface or the entire outer surface of the current collector; a graphite-based coating layer which is formed on the upper surface of the electrode active material layer and comprises graphite, a conductive material, and a first polymer binder; and a porous coating layer which is formed on the upper surface of the graphite-based coating layer and comprises a second polymer binder.

Description

이차전지용 전극, 그를 포함하는 이차전지 및 케이블형 이차전지Electrode for secondary battery, secondary battery and cable type secondary battery comprising same
본 발명은 이차전지용 전극, 그를 포함하는 이차전지 및 케이블형 이차전지에 관한 것으로서, 더욱 자세하게는 금속계 전극 활물질층의 탈리 현상을 방지하고, 에너지 밀도 및 사이클 수명특성을 향상시킨 이차전지용 전극, 그를 포함하는 이차전지 및 케이블형 이차전지에 관한 것이다.The present invention relates to a secondary battery electrode, a secondary battery including the same, and a cable type secondary battery, and more particularly, to prevent detachment of the metal-based electrode active material layer, and to improve the energy density and cycle life characteristics, including the electrode for the secondary battery. It relates to a secondary battery and a cable type secondary battery.
본 출원은 2012년 12월 12일에 출원된 한국특허출원 제10-2012-0144396호 및 2013년 12월 12일에 출원된 한국특허출원 제10-2013-0154429호에 기초한 우선권을 주장하며, 해당 출원의 명세서 및 도면에 개시된 모든 내용은 본 출원에 원용된다.This application claims the priority based on Korean Patent Application No. 10-2012-0144396 filed December 12, 2012 and Korean Patent Application No. 10-2013-0154429 filed December 12, 2013, All content disclosed in the specification and drawings of an application is incorporated in this application.
최근 이차 전지는 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. 이차 전지는 한 번 쓰고 버리는 일차 전지에 비해 경제적인 이점과 환경적인 이점을 모두 제공한다.Recently, a secondary battery is a device that converts external electrical energy into chemical energy and stores it and generates electricity when needed. The term "rechargeable battery" is also used to mean that it can be charged multiple times. Commonly used secondary batteries include lead storage batteries, nickel cadmium batteries (NiCd), nickel hydrogen storage 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.
이차 전지는 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. Examples are devices, handhelds, tools, and uninterruptible power supplies that help start up 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 kinds of conventional devices, and the demand for secondary batteries is exploding. In addition, hybrid vehicles and electric vehicles have been put to practical use in terms of prevention of environmental pollution, and these next-generation vehicles employ technologies that use secondary batteries to reduce value, weight, and extend life.
일반적으로 이차전지는 원통형, 각형 또는 파우치형의 전지가 대부분이다. 이는 이차전지는 음극, 양극 및 분리막으로 구성된 전극조립체를 원통형 또는 각형의 금속캔이나 알루미늄 라미네이트 시트의 파우치형 케이스 내부에 장착하고, 상기 전극 조립체에 전해질을 주입시켜 제조하기 때문이다. 따라서, 이차전지 장착을 위한 일정한 공간이 필수적으로 요구되므로, 이러한 이차전지의 원통형, 각형 또는 파우치형의 형태는 다양한 형태의 휴대용 장치의 개발에 대한 제약으로 작용하게 되는 문제점이 있다. 이에, 형태의 변형이 용이한 신규한 형태의 이차전지가 요구되고 있다.In general, secondary batteries are cylindrical, rectangular or pouch type batteries. This is because the secondary battery is manufactured by mounting an electrode assembly composed of a negative electrode, a positive electrode, and a separator inside a pouch-shaped case of a cylindrical or rectangular metal can or an aluminum laminate sheet, and injecting an electrolyte into the electrode assembly. Therefore, since a certain space for mounting the secondary battery is essentially required, the cylindrical, square or pouch type of the secondary battery has a problem in that it acts as a limitation for the development of various types of portable devices. Accordingly, there is a need for a new type of secondary battery that is easily deformed.
이러한 요구에 대하여, 단면적 직경에 대해 길이의 비가 매우 큰 전지인 케이블형 이차전지가 제안되었다. 다만, 이러한 케이블형 이차전지는 형태의 변형에 따른 외력에 의한 스트레스 또는 충방전시 전극 활물질층의 급격한 부피 팽창 등으로 인해 전극 활물질층의 탈리 현상이 일어나 용량 감소 및 사이클 수명특성 열화 현상이 발생할 수 있다.For this demand, a cable type secondary battery has been proposed which is a battery having a very large ratio of length to cross sectional diameter. However, in the cable type secondary battery, desorption of the electrode active material layer may occur due to stress caused by external force or rapid volume expansion of the electrode active material layer during charge and discharge, resulting in a decrease in capacity and deterioration of cycle life characteristics. have.
이러한 문제점을 해결하기 위해 전극 활물질층의 상부면에 고분자 바인더 코팅층을 더 형성할 수도 있다. 이 경우 전지의 사이클 수명특성을 향상시킬 수는 있지만, 이러한 고분자 바인더 코팅층은, 내부에 기공이 거의 존재하지 않기 때문에, 전극 활물질층으로의 전해액 유입을 방해하기 때문에 전극 저항이 증가하는 문제점이 발생할 수 있다.In order to solve this problem, a polymer binder coating layer may be further formed on the upper surface of the electrode active material layer. In this case, the cycle life characteristics of the battery may be improved, but since the polymer binder coating layer has little pores therein, the electrode resistance may increase because it prevents the electrolyte from flowing into the electrode active material layer. have.
그리고, 특히, 금속계 전극 활물질의 경우, 흑연계 전극 활물질 대비 방전 프로파일의 반응 전위가 높기 때문에, 풀셀을 제작하여 성능평가를 하게 되면, 에너지 밀도가 낮게 측정되는 단점이 있다.In particular, in the case of the metal-based electrode active material, since the reaction potential of the discharge profile is higher than that of the graphite-based electrode active material, when the full cell is manufactured and evaluated for performance, the energy density is low.
따라서 본 발명이 해결하고자 하는 과제는, 금속계 전극 활물질층의 탈리 현상을 방지하여 우수한 전지 수명 특성을 확보하고, 에너지 밀도를 향상시킴과 동시에, 전극 활물질층으로의 전해액 유입을 원활하도록 하여 전극 저항의 증가를 방지할 수 있고, 전극의 유연성이 향상된 이차전지용 전극, 그를 포함하는 이차전지 및 케이블형 이차전지를 제공하는 것이다.Accordingly, the problem to be solved by the present invention is to prevent the desorption phenomenon of the metal-based electrode active material layer to ensure excellent battery life characteristics, to improve the energy density, and to smoothly flow the electrolyte into the electrode active material layer of electrode resistance It is possible to prevent an increase and to provide an electrode for a secondary battery having improved electrode flexibility, a secondary battery including the same, and a cable type secondary battery.
상기 과제를 해결하기 위하여, 본 발명의 일 측면에 따르면, 집전체; 상기 집전체의 적어도 일면 또는 외면 전체에 형성되는 전극 활물질층; 상기 전극 활물질층의 상면에 형성되며, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층; 및 상기 흑연계 코팅층의 상면에 형성되며, 제2 고분자 바인더를 포함하는 다공성 코팅층;을 구비하는 이차전지용 전극이 제공된다.In order to solve the above problems, according to an aspect of the present invention, a current collector; An electrode active material layer formed on at least one surface or an entire outer surface of the current collector; A graphite coating layer formed on an upper surface of the electrode active material layer and including graphite, a conductive material, and a first polymer binder; And a porous coating layer formed on an upper surface of the graphite coating layer and including a second polymer binder.
이때, 상기 집전체는, 평면상의 집전체, 중공형의 집전체, 와이어형 집전체, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체일 수 있다.In this case, the current collector may be a planar current collector, a hollow current collector, a wire current collector, a wound wire current collector, a wound sheet current collector, or a mesh current collector.
그리고, 상기 흑연, 상기 도전재 및 상기 제1 고분자 바인더의 중량비가, 50:10:40 내지 90:1:9일 수 있다.The weight ratio of the graphite, the conductive material, and the first polymer binder may be 50:10:40 to 90: 1: 9.
그리고, 상기 흑연계 코팅층에 형성된 기공의 크기가, 0.1 ㎛ 내지 5 ㎛이고, 기공도가 10 내지 70 %일 수 있다.The pore size formed in the graphite coating layer may be 0.1 μm to 5 μm, and the porosity may be 10 to 70%.
그리고, 상기 도전재는, 카본 블랙, 아세틸렌 블랙, 케첸 블랙, 탄소 섬유, 탄소 나노튜브, 그래핀으로 이루어진 군으로부터 선택되는 어느 하나 또는 이들 중 2종 이상의 혼합물을 포함할 수 있다.The conductive material may include any one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fiber, carbon nanotube, and graphene, or a mixture of two or more thereof.
그리고, 상기 제1 고분자 바인더는, 폴리비닐리덴 풀루오라이드 (polyvinylidene fluoride, PVDF), 헥사풀루오로프로필렌 (hexafluoro propylene, HFP), 폴리비닐리덴 풀루오라이드-헥사풀루오로프로필렌 (polyvinylidene fluoride-co-hexafluoro propylene), 폴리비닐리덴 풀루오라이드-트리클로로에틸렌(polyvinylidene fluoride-co-trichloroethylene), 폴리부틸 아크릴레이트 (polybutyl acrylate), 폴리메틸 메타크릴레이트 (polymethyl methacrylate), 폴리아크릴로니트릴 (polyacrylonitrile), 폴리비닐피롤리돈 (polyvinylpyrrolidone), 폴리비닐아세테이트 (polyvinylacetate), 에틸렌 비닐 아세테이트 공중합체 (polyethylene-co-vinyl acetate), 폴리에틸렌 옥사이드 (polyethylene oxide), 폴리아릴레이트 (polyarylate), 셀룰로오스 아세테이트 (cellulose acetate), 셀룰로오스 아세테이트 부틸레이트 (cellulose acetate butyrate), 셀룰로오스 아세테이트 프로피오네이트 (cellulose acetate propionate), 시아노에틸풀루란 (cyanoethylpullulan), 시아노에틸폴리비닐알콜 (cyanoethylpolyvinylalcohol), 시아노에틸셀룰로오스 (cyanoethylcellulose), 시아노에틸수크로오스 (cyanoethylsucrose), 풀루란 (pullulan), 카르복실 메틸 셀룰로오스 (carboxyl methyl cellulose), 스티렌부타디엔 고무 (styrene-butadiene rubber), 아크릴로니트릴스티렌부타디엔 공중합체 (acrylonitrile-styrene-butadiene copolymer) 및 폴리이미드 (polyimide)로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있다.In addition, the first polymer binder is polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafulopropylene (polyvinylidene fluoride-) co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile ), Polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl acetate copolymer, polyethylene oxide, polyarylate, cellulose acetate acetate), cellulose acetate butyrate, cellulose acetate Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, Any one selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer and polyimide Mixtures of two or more of them.
한편, 상기 다공성 코팅층에 형성된 기공의 크기가, 0.01 ㎛ 내지 10 ㎛이고, 기공도가 5 내지 95 %일 수 있다.On the other hand, the size of the pores formed in the porous coating layer, 0.01 ㎛ to 10 ㎛, porosity may be 5 to 95%.
그리고, 상기 다공성 코팅층은, 무기물 입자를 더 포함할 수 있다.The porous coating layer may further include inorganic particles.
여기서, 상기 무기물 입자와 상기 제2 고분자 바인더의 중량비가, 10:90 내지 95:5일 수 있다.Here, the weight ratio of the inorganic particles and the second polymer binder may be 10:90 to 95: 5.
그리고, 상기 무기물 입자는, 유전율 상수가 5 이상인 무기물 입자, 리튬 이온 전달 능력을 갖는 무기물 입자 또는 이들의 혼합물일 수 있다.The inorganic particles may be inorganic particles having a dielectric constant of 5 or more, inorganic particles having a lithium ion transfer ability, or a mixture thereof.
이때, 상기 유전율 상수가 5 이상인 무기물 입자는, BaTiO3, Pb(Zrx, Ti1-x)O3(PZT, 여기서, 0<x<1임), Pb1-xLaxZr1-yTiyO3(PLZT, 여기서, 0 < x < 1, 0 < y < 1임), (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-PT, 여기서, 0 < x < 1), 하프니아(HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, SiC, SiO2, AlOOH, Al(OH)3 및 TiO2로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있다.In this case, the inorganic particles having a dielectric constant of 5 or more include BaTiO 3 , Pb (Zr x , Ti 1-x ) O 3 (PZT, where 0 <x <1), and Pb 1-x La x Zr 1-y Ti y O 3 (PLZT, where 0 <x <1, 0 <y <1), (1-x) Pb (Mg 1/3 Nb 2/3 ) O 3 -xPbTiO 3 (PMN-PT, where , 0 <x <1), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , SiC, SiO 2 , It may be any one selected from the group consisting of AlOOH, Al (OH) 3 and TiO 2 or a mixture of two or more thereof.
그리고, 상기 리튬 이온 전달 능력을 갖는 무기물 입자는, 리튬 포스페이트(Li3PO4), 리튬 티타늄 포스페이트(LixTiy(PO4)3, 0<x<2, 0<y<3), 리튬 알루미늄 티타늄 포스페이트(LixAlyTiz(PO4)3, 0<x<2, 0<y<1, 0<z<3), (LiAlTiP)xOy계열 글래스(0<x<4, 0<y<13), 리튬 란탄 티타네이트(LixLayTiO3, 0<x<2, 0<y<3), 리튬 게르마니움 티오포스페이트(LixGeyPzSw, 0<x<4, 0<y<1, 0<z<1, 0<w<5), 리튬 나이트라이드(LixNy, 0<x<4, 0<y<2), SiS2(LixSiySz, 0<x<3, 0<y<2, 0<z<4)계열 글래스 및 P2S5(LixPySz, 0<x<3, 0<y<3, 0<z<7)계열 글래스로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있다.In addition, the inorganic particles having the lithium ion transfer ability include lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li x Ti y (PO 4 ) 3 , 0 <x <2, 0 <y <3), lithium Aluminum Titanium Phosphate (Li x Al y Ti z (PO 4 ) 3 , 0 <x <2, 0 <y <1, 0 <z <3), (LiAlTiP) x O y series glass (0 <x <4, 0 <y <13), lithium lanthanum titanate (Li x La y TiO 3, 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 < x <4, 0 <y <1, 0 <z <1, 0 <w <5), lithium nitride (Li x N y , 0 <x <4, 0 <y <2), SiS 2 (Li x Si y S z , 0 <x <3, 0 <y <2, 0 <z <4) series glass and P 2 S 5 (Li x P y S z , 0 <x <3, 0 <y <3, 0 <z <7) can be any one selected from the group consisting of glass or a mixture of two or more thereof.
그리고, 상기 무기물 입자의 평균 입경이 10 nm 내지 5 ㎛일 수 있다.The average particle diameter of the inorganic particles may be 10 nm to 5 μm.
그리고, 상기 제2 고분자 바인더는, 폴리비닐리덴 풀루오라이드 (polyvinylidene fluoride, PVDF), 헥사풀루오로프로필렌 (hexafluoro propylene, HFP), 폴리비닐리덴 풀루오라이드-헥사풀루오로프로필렌 (polyvinylidene fluoride-co-hexafluoro propylene), 폴리비닐리덴 풀루오라이드-트리클로로에틸렌(polyvinylidene fluoride-co-trichloroethylene), 폴리부틸 아크릴레이트 (polybutyl acrylate), 폴리메틸 메타크릴레이트 (polymethyl methacrylate), 폴리아크릴로니트릴 (polyacrylonitrile), 폴리비닐피롤리돈 (polyvinylpyrrolidone), 폴리비닐아세테이트 (polyvinylacetate), 에틸렌 비닐 아세테이트 공중합체 (polyethylene-co-vinyl acetate), 폴리에틸렌 옥사이드 (polyethylene oxide), 폴리아릴레이트 (polyarylate), 셀룰로오스 아세테이트 (cellulose acetate), 셀룰로오스 아세테이트 부틸레이트 (cellulose acetate butyrate), 셀룰로오스 아세테이트 프로피오네이트 (cellulose acetate propionate), 시아노에틸풀루란 (cyanoethylpullulan), 시아노에틸폴리비닐알콜 (cyanoethylpolyvinylalcohol), 시아노에틸셀룰로오스 (cyanoethylcellulose), 시아노에틸수크로오스 (cyanoethylsucrose), 풀루란 (pullulan), 카르복실 메틸 셀룰로오스 (carboxyl methyl cellulose), 스티렌부타디엔 고무 (styrene-butadiene rubber), 아크릴로니트릴스티렌부타디엔 공중합체 (acrylonitrile-styrene-butadiene copolymer) 및 폴리이미드 (polyimide)로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있다.The second polymer binder may be polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafuluropropylene (polyvinylidene fluoride-) co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile ), Polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl acetate copolymer, polyethylene oxide, polyarylate, cellulose acetate acetate), cellulose acetate butyrate, cellulose acetate Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, Any one selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer and polyimide Mixtures of two or more of them.
한편, 상기 이차전지용 전극은, 음극일 수 있다.On the other hand, the secondary battery electrode may be a negative electrode.
이때, 상기 전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx);로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것일 수 있다.In this case, the electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni or Fe metals (Me) ; Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
한편, 본 발명의 일 측면에 따르면, 양극, 음극, 상기 양극과 상기 음극의 사이에 개재되는 세퍼레이터, 및 비수전해액을 포함하는 이차전지에 있어서, 상기 음극은 본 발명의 이차전지용 전극인 이차전지가 제공된다.On the other hand, according to an aspect of the present invention, in the secondary battery comprising a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, the negative electrode is a secondary battery electrode of the secondary battery of the present invention Is provided.
그리고, 본 발명의 다른 측면에 따르면, 전해질을 포함하는 리튬이온 공급 코어부; 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 내부전극; 상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지가 제공된다.And, according to another aspect of the invention, the lithium ion supply core portion containing an electrolyte; An internal current collector having an open structure formed around an outer surface of the lithium ion supply core part, an internal electrode active material layer formed on an outer surface of the internal current collector, and an outer surface of the internal electrode active material layer, and formed of graphite, a conductive material, and a first polymer An internal electrode having a graphite coating layer including a binder, and a porous coating layer formed on an outer surface of the graphite coating layer and including a second polymer binder; A separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode; And an external electrode formed surrounding the outer surface of the separation layer, the external electrode including an external current collector and an external electrode active material layer, the cable type secondary battery having a horizontal cross section and extending in the longitudinal direction.
이때, 상기 열린 구조의 내부집전체는, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체일 수 있다.In this case, the internal current collector of the open structure may be a wound wire current collector, a wound sheet current collector, or a mesh current collector.
그리고, 상기 내부전극은 음극이며, 상기 내부전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx);로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것일 수 있다.The internal electrode is a cathode, and the internal electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
그리고, 상기 외부전극은, 상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층 및 상기 외부전극 활물질층의 외면을 둘러싸며 형성된 외부집전체를 구비하거나, 상기 분리층의 외면을 둘러싸며 형성된 외부집전체 및 상기 외부집전체의 외면을 둘러싸며 형성된 외부전극 활물질층을 구비하거나, 상기 분리층의 외면을 둘러싸며 형성된 외부집전체 및 상기 외부집전체의 외면을 둘러싸며 상기 분리층과 접촉하도록 형성된 외부전극 활물질층을 구비하거나, 또는 상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층 및 상기 외부전극 활물질층 내에 피복되어 있고, 상기 분리층의 외면을 이격된 상태로 둘러싸며 형성된 외부집전체를 구비하는 것일 수 있다.The external electrode may include an external electrode active material layer formed to surround the outer surface of the separation layer and an external current collector formed to surround the outer surface of the external electrode active material layer, or an external house formed to surround the outer surface of the separation layer. External electrode active material layer formed surrounding the outer surface of the whole and the outer current collector, or the outer current collector formed surrounding the outer surface of the separation layer and the outer surface formed to contact the separation layer surrounding the outer surface of the outer current collector An external electrode active material layer provided with an electrode active material layer or surrounding the outer surface of the separation layer and covered with the outer electrode active material layer, and having an outer current collector formed while enclosing the outer surface of the separation layer with a spaced apart state; It may be.
그리고, 본 발명의 다른 측면에 따르면, 전해질을 포함하는 리튬이온 공급 코어부; 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체 및 상기 내부집전체의 외면에 형성된 내부전극 활물질층을 구비하는 내부전극; 상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지가 제공된다.And, according to another aspect of the invention, the lithium ion supply core portion containing an electrolyte; An inner electrode including an inner current collector having an open structure formed around an outer surface of the lithium ion supply core and an inner electrode active material layer formed on an outer surface of the inner current collector; A separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode; And a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. There is provided a cable type secondary battery having a horizontal cross section including an external electrode and extending in a length direction.
이때, 상기 외부전극은 음극이며, 상기 외부전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx)로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것일 수 있다.In this case, the external electrode is a cathode, the external electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And it may include any one active material particles selected from the group consisting of oxides (MeOx) of the metals (Me) or a mixture of two or more thereof.
그리고, 상기 외부전극은, 상기 분리층의 외면을 둘러싸며 형성된 제2 고분자 바인더를 포함하는 다공성 코팅층, 상기 다공성 코팅층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 상기 흑연계 코팅층의 외면을 둘러싸며 형성된 외부전극 활물질층, 및 상기 외부전극 활물질층의 외면을 둘러싸며 형성된 외부집전체를 구비하거나, 상기 분리층의 외면을 둘러싸며 형성된 외부집전체, 상기 외부집전체의 외면을 둘러싸며 형성된 외부전극 활물질층, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하거나, 상기 분리층의 외면을 둘러싸며 형성된 외부집전체, 상기 외부집전체의 외면을 둘러싸며 상기 분리층과 접촉하도록 형성된 외부전극 활물질층, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하거나, 또는 상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층, 상기 외부전극 활물질층 내에 피복되어 있고, 상기 분리층의 외면을 이격된 상태로 둘러싸며 형성된 외부집전체, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 것일 수 있다.The external electrode may include a porous coating layer including a second polymer binder formed to surround the outer surface of the separation layer, and surround the outer surface of the porous coating layer and include graphite, a conductive material, and a first polymer binder. An external current collector having an associated coating layer, an external electrode active material layer formed surrounding the outer surface of the graphite coating layer, and an external current collector formed surrounding the outer surface of the external electrode active material layer, or an external current collector formed surrounding the outer surface of the separation layer, An external electrode active material layer formed surrounding the outer surface of the external current collector, a graphite-based coating layer formed surrounding the outer surface of the external electrode active material layer, the graphite-based coating layer including graphite, a conductive material and a first polymer binder, and the graphite-based coating layer Is formed surrounding the outer surface, and provided with a porous coating layer comprising a second polymer binder, or the outer surface of the separation layer The outer current collector is formed to surround the outer surface of the outer current collector, the outer electrode active material layer formed to contact the separation layer, the outer surface of the outer electrode active material layer formed to surround the graphite, the conductive material and the first polymer binder An external electrode active material layer formed surrounding the outer surface of the graphite coating layer and the graphite coating layer, including a porous coating layer including a second polymer binder or surrounding the outer surface of the separation layer, and the external electrode. It is coated in the active material layer, and formed to surround the outer surface of the separation layer in a spaced apart state, and formed to surround the outer surface of the external electrode active material layer, black including graphite, a conductive material and a first polymer binder A porous coating layer is formed surrounding the outer surface of the associated coating layer and the graphite coating layer, and includes a second polymer binder. It may be to.
한편, 상기 분리층은, 전해질층 또는 세퍼레이터일 수 있다.Meanwhile, the separation layer may be an electrolyte layer or a separator.
이때, 상기 전해질층은, PEO, PVdF, PVdF-HFP, 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; 중에서 선택된 전해질을 포함하는 것일 수 있다.At this time, the electrolyte layer, a gel polymer electrolyte using PEO, PVdF, PVdF-HFP, PMMA, PAN or PVAC; Or a solid electrolyte using PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES) or polyvinyl acetate (PVAc); It may be to include an electrolyte selected from.
그리고, 상기 전해질층은, 리튬염을 더 포함할 수 있다.The electrolyte layer may further include a lithium salt.
이때, 상기 리튬염은, LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, 클로로보란리튬, 저급지방족카르본산리튬 및 테트라페닐붕산리튬 중에서 선택된 1종 또는 2종 이상일 수 있다.At this time, the lithium salt, 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, may be one or two or more selected from lithium chloroborane, lithium lower aliphatic carbonate and lithium tetraphenyl borate.
그리고, 상기 세퍼레이터는, 에틸렌 단독중합체, 프로필렌 단독중합체, 에틸렌-부텐 공중합체, 에틸렌-헥센 공중합체 및 에틸렌-메타크릴레이트 공중합체로 이루어진 군에서 선택된 폴리올레핀계 고분자로 제조한 다공성 고분자 기재; 폴리에스테르, 폴리아세탈, 폴리아미드, 폴리카보네이트, 폴리이미드, 폴리에테르에테르케톤, 폴리에테르설폰, 폴리페닐렌옥사이드, 폴리페닐렌설파이트 및 폴리에틸렌나프탈렌으로 이루어진 군에서 선택된 고분자로 제조한 다공성 고분자 기재; 또는 무기물 입자 및 바인더 고분자의 혼합물로 형성된 다공성 고분자 기재일 수 있다.The separator may include a porous polymer substrate 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; A porous polymer 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; Or a porous polymer substrate formed of a mixture of inorganic particles and a binder polymer.
한편, 본 발명의 또 다른 측면에 따르면, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지가 제공된다.On the other hand, according to another aspect of the invention, two or more lithium ion supply core portion containing an electrolyte; An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer; At least two internal electrodes formed on the outer surface of the graphite coating layer including one polymer binder and formed on an outer surface of the graphite coating layer, and having a porous coating layer including a second polymer binder; A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And an external electrode formed surrounding the outer surface of the separation layer, the external electrode including an external current collector and an external electrode active material layer, the cable type secondary battery having a horizontal cross section and extending in the longitudinal direction.
그리고, 본 발명의 또 다른 측면에 따르면, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층 및 상기 다공성 코팅층의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 및 상기 내부전극들의 외면을 함께 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지가 제공된다.And, according to another aspect of the invention, two or more lithium ion supply core portion containing an electrolyte; An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer; A graphite-based coating layer comprising a polymer binder, a porous coating layer formed on the outer surface of the graphite-based coating layer, and a separation layer for preventing a short circuit of the electrode formed surrounding the outer surface of the porous coating layer; Two or more internal electrodes disposed in parallel to each other; And an outer electrode formed to surround the outer surfaces of the inner electrodes and having an outer current collector and an outer electrode active material layer, the cable type secondary battery having a horizontal cross section and extending in the length direction.
그리고, 본 발명의 또 다른 측면에 따르면, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체 및 상기 내부집전체의 외면을 둘러싸며 형성된 내부전극 활물질층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지가 제공된다.And, according to another aspect of the invention, two or more lithium ion supply core portion containing an electrolyte; Two or more internal electrodes disposed in parallel with each other including an inner current collector having an open structure formed around an outer surface of each lithium ion supply core and an inner electrode active material layer formed surrounding the outer surface of the inner current collector; A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. There is provided a cable type secondary battery having a horizontal cross section including an external electrode and extending in a length direction.
그리고, 본 발명의 또 다른 측면에 따르면, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면을 둘러싸며 형성된 내부전극 활물질층 및 상기 내부전극 활물질층의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 및 상기 내부전극들의 외면을 함께 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지가 제공된다.And, according to another aspect of the invention, two or more lithium ion supply core portion containing an electrolyte; An inner current collector having an open structure formed surrounding the outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed surrounding the outer surface of the inner current collector, and a short circuit of the electrode formed surrounding the outer surface of the inner electrode active material layer Two or more internal electrodes disposed in parallel with each other having a separation layer for preventing; And a porous coating layer formed to surround the outer surfaces of the inner electrodes, the graphite-based coating layer including an outer current collector, an outer electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. There is provided a cable-type secondary battery having a horizontal cross-section including an external electrode extending in the longitudinal direction.
본 발명에 따르면, 케이블형 이차전지 등의 형태의 변형에 따른 외력에 의한 스트레스 또는 충방전시 전극 활물질층의 급격한 부피 팽창 등으로 인해 발생할 수 있는 전극 활물질층의 탈리 현상을 억제함으로써 전지의 용량 감소를 방지하고, 전극의 도전성을 증가시키며, 우수한 전지 성능을 보이는 흑연계 코팅층의 도입을 통해 초기 효율 및 전지의 사이클 수명특성을 향상시킬 수 있다.According to the present invention, the capacity of the battery is reduced by suppressing the detachment phenomenon of the electrode active material layer, which may occur due to the stress caused by external force or the sudden volume expansion of the electrode active material layer during charging and discharging. By preventing the increase, the conductivity of the electrode, and the introduction of a graphite-based coating layer exhibiting excellent battery performance can improve the initial efficiency and cycle life characteristics of the battery.
특히, 금속계 전극 활물질이 코팅된 전극을 포함하는 풀셀의 반응 전위를 높여 에너지 밀도를 향상시킬 수 있다.In particular, it is possible to improve the energy density by increasing the reaction potential of the full cell including the electrode coated with the metal-based electrode active material.
그리고 동시에, 전극 활물질층으로의 전해액 유입을 원활하도록 하여 전극의 저항 증가를 방지함으로써 전지의 성능을 향상시킬 수 있으며, 굽힘과 비틀림 등의 외력에 의해, 전극 활물질층의 상면에 형성된 흑연계 코팅층에 크랙 (crack)이 발생하거나, 떨어져 나가는 것을 억제할 수 있어 전극의 유연성을 더욱 향상시킬 수 있다.At the same time, the performance of the battery can be improved by smoothly flowing the electrolyte into the electrode active material layer to prevent the increase of the resistance of the electrode, and by the external force such as bending and twisting, to the graphite coating layer formed on the upper surface of the electrode active material layer. Cracking or falling off can be suppressed, thereby further improving the flexibility of the electrode.
본 명세서에 첨부되는 다음의 도면은 본 발명의 바람직한 실시예를 예시하는 것이며, 전술한 발명의 내용과 함께 본 발명의 기술사상을 더욱 이해시키는 역할을 하는 것이므로, 본 발명은 그러한 도면에 기재된 사항에만 한정되어 해석되어서는 아니 된다.The following drawings, which are attached to this specification, illustrate exemplary embodiments of the present invention, and together with the contents of the present invention serve to further understand the technical spirit of the present invention, the present invention is limited to the matters described in such drawings. It should not be construed as limited.
도 1은 본 발명의 일 실시예에 따른, 와이어형 집전체를 포함하는 케이블형 이차전지용 전극의 사시도를 나타낸 도면이다.1 is a view showing a perspective view of an electrode for a cable-type secondary battery including a wire-type current collector according to an embodiment of the present invention.
도 2는 본 발명의 일 실시예에 따른, 중공형의 집전체를 포함하는 케이블형 이차전지용 전극의 사시도를 나타낸 도면이다.2 is a view showing a perspective view of an electrode for a cable type secondary battery including a hollow current collector according to an embodiment of the present invention.
도 3은 본 발명의 일 실시예에 따른, 하나의 내부전극을 포함하는 케이블형 이차전지의 사시도를 나타낸 도면이다.3 is a perspective view of a cable type secondary battery including one internal electrode according to an embodiment of the present invention.
도 4는 본 발명의 다른 실시예에 따른, 하나의 내부전극을 포함하는 케이블형 이차전지의 사시도를 나타낸 도면이다.4 is a view showing a perspective view of a cable-type secondary battery including one internal electrode according to another embodiment of the present invention.
도 5는 본 발명의 일 실시예에 따른, 2 이상의 내부전극을 포함하는 케이블형 이차전지의 단면도를 나타낸 도면이다.5 is a cross-sectional view of a cable type secondary battery including two or more internal electrodes according to an embodiment of the present invention.
도 6은 본 발명의 다른 실시예에 따른, 2 이상의 내부전극을 포함하는 케이블형 이차전지의 단면도를 나타낸 도면이다.6 is a cross-sectional view of a cable type secondary battery including two or more internal electrodes according to another embodiment of the present invention.
도 7은 본 발명의 일 실시예에 따라 제조된 흑연계 코팅층이 형성된 와이어형 전극을 나타낸 SEM 사진이다.7 is a SEM photograph showing a wire-type electrode having a graphite coating layer prepared according to an embodiment of the present invention.
도 8은 본 발명의 일 실시예에 따라 제조된 다공성 코팅층이 형성된 와이어형 전극을 나타낸 SEM 사진이다.Figure 8 is a SEM photograph showing a wire-type electrode formed with a porous coating layer prepared according to an embodiment of the present invention.
도 9는 본 발명의 일 실시예와 비교예에 따른 충방전 프로파일을 방전 용량에 대해 정규화하여 나타낸 그래프이다.9 is a graph showing normalized charging and discharging profiles for discharge capacities according to one embodiment and a comparative example of the present invention.
도 10은 본 발명의 일 실시예와 비교예에 따른 전지의 충방전 사이클 수명 특성을 나타낸 그래프이다.10 is a graph showing the charge and discharge cycle life characteristics of the battery according to an embodiment and a comparative example of the present invention.
[부호의 설명][Description of the code]
10, 20: 케이블형 이차전지용 전극 11: 와이어형 집전체10, 20: electrode for cable type secondary battery 11: wire type current collector
12, 22: 전극 활물질층 13, 23: 흑연계 코팅층12, 22: electrode active material layer 13, 23: graphite coating layer
14, 24: 다공성 코팅층 21: 중공형의 집전체14, 24: porous coating layer 21: hollow current collector
100, 200, 300, 400: 케이블형 이차전지100, 200, 300, 400: cable type secondary battery
110, 210, 310, 410: 리튬이온 공급 코어부110, 210, 310, 410: lithium ion supply core
120, 220, 320, 420: 내부집전체120, 220, 320, 420: internal current collector
130, 230, 330, 430: 내부전극 활물질층130, 230, 330, and 430: internal electrode active material layer
140, 240, 340, 440: 분리층140, 240, 340, 440: separation layer
150, 250, 350, 450: 외부전극 활물질층150, 250, 350, 450: external electrode active material layer
160, 260, 360, 460: 외부집전체160, 260, 360, 460: External current collector
170, 270, 370, 470: 보호피복170, 270, 370, 470: protective clothing
131, 251, 331, 451: 흑연계 코팅층131, 251, 331, 451: graphite coating layer
132, 252, 332, 452: 다공성 코팅층132, 252, 332, 452: porous coating layer
이하, 본 발명을 도면을 참조하여 상세히 설명하기로 한다. 본 명세서 및 청구범위에 사용된 용어나 단어는 통상적이거나 사전적인 의미로 한정해서 해석되어서는 아니 되며, 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.Hereinafter, the present invention will be described in detail with reference to the drawings. The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.
또한, 본 명세서에 기재된 실시예와 도면에 도시된 구성은 본 발명의 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.In addition, the configuration shown in the embodiments and drawings described herein are only one of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.
본 발명에 따른 이차전지용 전극은, 집전체; 상기 집전체의 적어도 일면 또는 외면 전체에 형성되는 전극 활물질층; 상기 전극 활물질층의 상면에 형성되며, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층; 및 상기 흑연계 코팅층의 상면에 형성되며, 제2 고분자 바인더를 포함하는 다공성 코팅층;을 구비한다.Secondary battery electrode according to the present invention, the current collector; An electrode active material layer formed on at least one surface or an entire outer surface of the current collector; A graphite coating layer formed on an upper surface of the electrode active material layer and including graphite, a conductive material, and a first polymer binder; And a porous coating layer formed on an upper surface of the graphite coating layer and including a second polymer binder.
이때, 상기 집전체는, 평면상의 집전체, 중공형의 집전체, 와이어형 집전체, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체일 수 있으나, 이에만 한정하는 것은 아니고, 이차전지의 형태에 따라 다양한 종류의 집전체가 가능하다.In this case, the current collector may be a planar current collector, a hollow current collector, a wire current collector, a wound wire current collector, a wound sheet current collector, or a mesh current collector, but is not limited thereto. According to the shape of the secondary battery, various kinds of current collectors are possible.
이때, 상기 집전체가 평면상의 집전체인 경우에는 상기 집전체의 상면 또는 하면 중 적어도 일면에 전극 활물질층이 형성될 수 있고, 상기 집전체가 중공형의 집전체인 경우에는 상기 집전체의 내부에 존재하는 면과 외부에 존재하는 면 중 적어도 일면에 전극 활물질층이 형성될 수 있고, 와이어형 집전체인 경우에는 집전체의 표면 전체에 전극 활물질층이 형성될 수 있으며, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체인 경우에는 상기 집전체의 내부에 존재하는 면과 외부에 존재하는 면 중 적어도 일면에 전극 활물질층이 형성될 수도 있고, 상기 집전체의 표면 전체를 둘러싸며 형성될 수도 있다.In this case, when the current collector is a planar current collector, an electrode active material layer may be formed on at least one surface of an upper surface or a lower surface of the current collector. When the current collector is a hollow current collector, the inside of the current collector may be formed. The electrode active material layer may be formed on at least one of a surface existing in the surface and an external surface, and in the case of a wire-type current collector, the electrode active material layer may be formed on the entire surface of the current collector. In the case of a whole, a wound sheet current collector or a mesh current collector, an electrode active material layer may be formed on at least one of a surface existing inside and a surface existing outside of the current collector. It may be formed surrounding.
도 1은 본 발명의 일 실시예에 따른, 와이어형 집전체를 포함하는 케이블형 이차전지용 전극의 사시도를 나타낸 도면이고, 도 2는 본 발명의 일 실시예에 따른, 중공형의 집전체를 포함하는 케이블형 이차전지용 전극의 사시도를 나타낸 도면이다.1 is a view showing a perspective view of an electrode for a cable type secondary battery including a wire-type current collector according to an embodiment of the present invention, Figure 2 includes a hollow current collector, according to an embodiment of the present invention It is a figure which shows the perspective view of the cable type secondary battery electrode.
도 1을 참조하면, 본 발명에 따른 케이블형 이차전지용 전극(10)은, 와이어형 집전체(11); 상기 와이어형 집전체(11)의 표면 전체를 둘러싸며 형성된 전극 활물질층(12); 상기 전극 활물질층(12)의 상면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층(13); 및 상기 흑연계 코팅층(13)의 상면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층(14);을 구비하며, 길이방향으로 연장된다. 이때 상기 케이블형 이차전지용 전극(10)은, 하나 이상의 와이어가 코일형태 등으로 권선되거나, 둘 이상의 와이어가 서로 나선형 모양으로 꼬여 형성된 하나 이상의 와이어 복합체가 코일형태 등으로 권선됨으로써 케이블형 이차전지의 내부전극으로 사용될 수 있다.Referring to FIG. 1, an electrode 10 for a cable type secondary battery according to the present invention includes a wire type current collector 11; An electrode active material layer 12 formed surrounding the entire surface of the wire-shaped current collector 11; A graphite coating layer 13 formed surrounding the upper surface of the electrode active material layer 12 and including graphite, a conductive material, and a first polymer binder; And a porous coating layer 14 formed surrounding the upper surface of the graphite coating layer 13 and including a second polymer binder, and extending in the longitudinal direction. In this case, the cable type secondary battery electrode 10 may include one or more wires wound in a coil shape or the like, or one or more wire composites in which two or more wires are twisted in a spiral shape are wound in a coil shape or the like to form an inside of the cable type secondary battery. Can be used as an electrode.
그리고, 도 2를 참조하면, 본 발명에 따른 케이블형 이차전지용 전극(20)은, 중공형의 집전체(21); 상기 중공형의 집전체(21)의 외부에 존재하는 면에 형성된 전극 활물질층(22); 상기 전극 활물질층(22)의 상면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층(23); 및 상기 흑연계 코팅층(23)의 상면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층(24);을 구비하며, 길이방향으로 연장된다. 이때 상기 케이블형 이차전지용 전극(20)은, 케이블형 이차전지의 외부전극으로 사용될 수 있다.And, referring to Figure 2, the cable-type secondary battery electrode 20 according to the present invention, the hollow current collector 21; An electrode active material layer 22 formed on a surface existing outside the hollow current collector 21; A graphite coating layer 23 formed surrounding the upper surface of the electrode active material layer 22 and including graphite, a conductive material, and a first polymer binder; And a porous coating layer 24 formed surrounding the upper surface of the graphite coating layer 23 and including a second polymer binder, and extending in the longitudinal direction. In this case, the cable type secondary battery electrode 20 may be used as an external electrode of the cable type secondary battery.
케이블형 이차전지용 전극으로서, 집전체에 형성되는 전극 활물질층은, 충방전시의 급격한 부피 팽창 또는 형태의 변형에 따른 외력에 의한 스트레스 등으로 인해 전극 활물질층의 탈리 현상이 발생하거나, 집전체로부터 완전히 떨어져 나갈 수 있다. 그 결과, 전극에서의 전기 전도성이 떨어져 용량 구현이 되지 않아, 초기 효율이 낮게 나타난다. 또한 전지의 사이클 수명특성도 매우 열악해진다. 특히, 전기 도금 또는 양극 산화법 등의 방법으로 형성된 금속계의 음극 활물질층의 경우에는 고분자 바인더와 도전재가 존재하지 않기 때문에, 탈리 현상이 더욱 심각할 수 있다. 또한, 금속계의 음극 활물질의 경우, 흑연계 전극 활물질 대비 방전 프로파일의 반응 전위가 높기 때문에, 풀셀을 제작하게 되면, 흑연계 전극 활물질을 사용한 것에 비해 에너지 밀도가 낮아지게 된다.As an electrode for a cable type secondary battery, the electrode active material layer formed on the current collector may have a detachment phenomenon of the electrode active material layer due to sudden volume expansion during charge and discharge or stress caused by external force due to deformation of the shape, or from the current collector. You can go off completely. As a result, the electrical conductivity at the electrode is poor, the capacity is not realized, the initial efficiency is low. In addition, the cycle life characteristics of the battery become very poor. In particular, in the case of the metal-based negative electrode active material layer formed by a method such as electroplating or anodizing, since the polymer binder and the conductive material do not exist, the detachment phenomenon may be more serious. In addition, in the case of the metal negative electrode active material, since the reaction potential of the discharge profile is higher than that of the graphite electrode active material, when the full cell is manufactured, the energy density is lower than that of the graphite electrode active material.
이러한 현상을 방지하기 위해, 본 발명에서는 전극 활물질층의 외면에, 흑연, 도전재 및 제1 고분자 바인더로 이루어진 흑연계 코팅층을 형성시키고, 상기 흑연계 코팅층의 외면에, 제2 고분자 바인더로 이루어진 다공성 코팅층을 형성시킴으로써, 전극 활물질층의 탈리 현상을 억제하여, 전지의 용량 감소를 방지하고, 전극의 도전성을 증가시켜 전지의 사이클 수명특성을 향상시킬 수 있고, 에너지 밀도를 증가시킬 수 있다.In order to prevent such a phenomenon, in the present invention, a graphite coating layer made of graphite, a conductive material and a first polymer binder is formed on the outer surface of the electrode active material layer, and the porous surface made of the second polymer binder is formed on the outer surface of the graphite coating layer. By forming the coating layer, it is possible to suppress the detachment phenomenon of the electrode active material layer, to prevent the reduction of the capacity of the battery, to increase the conductivity of the electrode to improve the cycle life characteristics of the battery, and to increase the energy density.
여기서, 상기 흑연계 코팅층은, 전극 활물질층의 이탈을 완화할 수 있는 완충지대(buffer region) 역할을 할 수 있고, 전도성이 우수한 도전재를 포함하고 있으며, 흑연계 코팅층 자체가 우수한 전지 특성을 보유하고 있기 때문에, 전극 활물질층의 탈리 현상을 방지함과 동시에, 초기 효율 향상 및 사이클 수명특성의 개선에 기여할 수 있다.Here, the graphite coating layer may serve as a buffer region that can alleviate the separation of the electrode active material layer, includes a conductive material having excellent conductivity, and the graphite coating layer itself has excellent battery characteristics. As a result, the detachment phenomenon of the electrode active material layer can be prevented and contributed to the improvement of initial efficiency and cycle life characteristics.
그리고, 굽힙 등에 의해 강한 외력이 가해지더라도 전극 활물질층의 탈리 현상이 억제되므로 케이블형 이차전지의 유동성 향상에도 기여하게 된다. 나아가 상기 다공성 코팅층에 존재하는 기공을 통해, 전극 활물질층으로의 전해액 유입을 원활하도록 하여 전극의 저항 증가를 방지함으로써 전지의 성능을 향상시킬 수 있다.Further, even when a strong external force is applied by bending or the like, desorption of the electrode active material layer is suppressed, thereby contributing to improvement of fluidity of the cable type secondary battery. Furthermore, through the pores present in the porous coating layer, it is possible to improve the performance of the battery by preventing the increase of the resistance of the electrode by smoothly flowing the electrolyte into the electrode active material layer.
이때, 상기 흑연, 상기 도전재 및 상기 제1 고분자 바인더의 중량비가, 50:10:40 내지 90:1:9일 수 있다. 이러한 수치범위를 만족함으로써 흑연계 코팅층의 전극 유연성을 확보하는 동시에 전극 저항 상승을 억제하는 효과가 발생한다.In this case, the weight ratio of the graphite, the conductive material and the first polymer binder may be 50:10:40 to 90: 1: 9. By satisfying such a numerical range, an effect of securing electrode flexibility of the graphite coating layer and suppressing electrode resistance increase occurs.
한편, 상기 흑연계 코팅층에는 전해액의 유입을 가능하도록 하기 위해 기공이 형성될 수 있는데, 이러한 기공은, 전극 활물질층의 탈리 억제를 위해 전극 활물질층을 구성하는 입자들의 크기보다 작아야 하며, 전해액이 전극으로의 유입을 활발하게 하기 위해 전해액의 리튬 이온의 용매화 반경보다 큰 것이 바람직하다. 이러한 조건을 만족하기 위해서, 상기 흑연계 코팅층에 형성된 기공의 크기는, 0.1 ㎛ 내지 5 ㎛일 수 있다. 그리고 전술한 효과를 달성하기 위하여, 상기 흑연계 코팅층의 기공도가 10 내지 70 %일 수 있다.On the other hand, pores may be formed in the graphite coating layer to enable the inflow of the electrolyte, and such pores should be smaller than the size of the particles constituting the electrode active material layer in order to suppress the detachment of the electrode active material layer, and the electrolyte may be the electrode. It is preferable that the solvation radius of the lithium ions of the electrolyte be greater than the solvating radius of the electrolyte solution to facilitate the inflow to the inlet. In order to satisfy these conditions, the pore size formed in the graphite coating layer may be 0.1 μm to 5 μm. And in order to achieve the above effect, the porosity of the graphite coating layer may be 10 to 70%.
그리고, 상기 흑연으로는, 천연 흑연 또는 인조 흑연 등, 일반적으로 사용하는 흑연이라면 제한되지 않는다.And as said graphite, if it is graphite generally used, such as natural graphite or artificial graphite, it will not restrict | limit.
그리고, 상기 도전재로는, 이차전지에서 화학변화를 일으키지 않는 전자 전도성 물질이면 특별한 제한이 없다. 일반적으로 카본 블랙, 아세틸렌 블랙, 케첸 블랙, 탄소 섬유, 탄소 나노튜브, 그래핀 등이 사용될 수 있고, 금속분말, 도전성 금속산화물, 유기 도전재 등의 사용이 가능하다. 현재 도전재로 시판되고 있는 상품으로는 아세틸렌 블랙계열 (쉐브론 케미컬 컴퍼니(Chevron Chemical Company) 또는 걸프 오일 컴퍼니 (Gulf Oil Company) 제품 등), EC 계열(아르막 컴퍼니 (Armak Company) 제품), 불칸 (Vulcan), XC-72(캐보트 컴퍼니(Cabot Company) 제품) 및 수퍼 P (엠엠엠(MMM)사 제품) 등이 있다.The conductive material is not particularly limited as long as it is an electronic conductive material that does not cause chemical change in the secondary battery. In general, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotubes, graphene and the like can be used, it is possible to use metal powder, conductive metal oxide, organic conductive material and the like. Products currently available as conductive materials include acetylene black series (Chevron Chemical Company or Gulf Oil Company), EC series (Armak Company), Vulcan ( Vulcan), XC-72 (manufactured by Cabot Company), and Super P (manufactured by MMM).
그리고, 상기 제1 고분자 바인더로는, 폴리비닐리덴 풀루오라이드 (polyvinylidene fluoride, PVDF), 헥사풀루오로프로필렌 (hexafluoro propylene, HFP), 폴리비닐리덴 풀루오라이드-헥사풀루오로프로필렌 (polyvinylidene fluoride-co-hexafluoro propylene), 폴리비닐리덴 풀루오라이드-트리클로로에틸렌(polyvinylidene fluoride-co-trichloroethylene), 폴리부틸 아크릴레이트 (polybutyl acrylate), 폴리메틸 메타크릴레이트 (polymethyl methacrylate), 폴리아크릴로니트릴 (polyacrylonitrile), 폴리비닐피롤리돈 (polyvinylpyrrolidone), 폴리비닐아세테이트 (polyvinylacetate), 에틸렌 비닐 아세테이트 공중합체 (polyethylene-co-vinyl acetate), 폴리에틸렌 옥사이드 (polyethylene oxide), 폴리아릴레이트 (polyarylate), 셀룰로오스 아세테이트 (cellulose acetate), 셀룰로오스 아세테이트 부틸레이트 (cellulose acetate butyrate), 셀룰로오스 아세테이트 프로피오네이트 (cellulose acetate propionate), 시아노에틸풀루란 (cyanoethylpullulan), 시아노에틸폴리비닐알콜 (cyanoethylpolyvinylalcohol), 시아노에틸셀룰로오스 (cyanoethylcellulose), 시아노에틸수크로오스 (cyanoethylsucrose), 풀루란 (pullulan), 카르복실 메틸 셀룰로오스 (carboxyl methyl cellulose), 스티렌부타디엔 고무 (styrene-butadiene rubber), 아크릴로니트릴스티렌부타디엔 공중합체 (acrylonitrile-styrene-butadiene copolymer) 및 폴리이미드 (polyimide)로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물이 사용될 수 있으나, 이에만 한정하는 것은 아니다.The first polymer binder may include polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), and polyvinylidene fluoride-hexafuluropropylene (polyvinylidene fluoride). -co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile ( polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate ( cellulose acetate, cellulose acetate butyrate, cellulose acetate Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, Any one selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer and polyimide Mixtures of two or more of them may be used, but are not limited thereto.
한편, 상기 다공성 코팅층은, 제조과정에서 상분리 또는 상전환을 통해 다공성의 기공구조를 형성할 수 있다.On the other hand, the porous coating layer, it is possible to form a porous pore structure through phase separation or phase inversion in the manufacturing process.
상기 다공성 코팅층에 형성된 기공은, 전극 활물질층의 탈리 억제를 위해 전극 활물질층을 구성하는 입자들의 크기보다 작아야 하며, 전해액이 전극으로의 유입을 활발하게 하기 위해 전해액의 리튬 이온의 용매화 반경보다 큰 것이 바람직하다. 이러한 조건을 만족하기 위해서, 상기 다공성 코팅층에 형성된 기공의 크기가, 0.01 ㎛ 내지 10 ㎛일 수 있다.The pores formed in the porous coating layer should be smaller than the size of the particles constituting the electrode active material layer to suppress the detachment of the electrode active material layer, the electrolyte is larger than the solvation radius of lithium ions of the electrolyte in order to facilitate the inflow to the electrode It is preferable. In order to satisfy these conditions, the size of the pores formed in the porous coating layer may be 0.01 ㎛ to 10 ㎛.
그리고 전술한 효과를 달성하기 위하여, 상기 다공성 코팅층의 기공도가 5 내지 95 %일 수 있다.And in order to achieve the above effects, the porosity of the porous coating layer may be 5 to 95%.
한편 상기 다공성 코팅층은, 무기물 입자를 더 포함하는 것일 수 있다.Meanwhile, the porous coating layer may further include inorganic particles.
이 경우, 상기 다공성 코팅층의 무기물 입자들은 충전되어 서로 접촉된 상태에서 상기 제2 고분자 바인더에 의해 서로 결착되고, 이로 인해 무기물 입자들 사이에 인터스티셜 볼륨(interstitial volume)이 형성되고, 상기 무기물 입자 사이의 인터스티셜 볼륨(interstitial volume)은 빈 공간이 되어 기공을 형성할 수 있다.In this case, the inorganic particles of the porous coating layer are filled with each other by the second polymer binder in a state of being in contact with each other, thereby forming an interstitial volume between the inorganic particles, the inorganic particles The interstitial volume between them may be empty to form pores.
이때, 상기 무기물 입자와 상기 고분자 바인더의 중량비는, 적절한 기공도를 확보하기 위해 10:90 내지 95:5일 수 있다.In this case, the weight ratio of the inorganic particles and the polymer binder may be 10:90 to 95: 5 in order to secure appropriate porosity.
그리고, 본 발명에서 사용될 수 있는 무기물 입자는 전기화학적으로 안정하기만 하면 특별히 제한되지 않는다. 즉, 본 발명에서 사용할 수 있는 무기물 입자는 적용되는 전기화학소자의 작동 전압 범위(예컨대, Li/Li+ 기준으로 0~5V)에서 산화 및/또는 환원 반응이 일어나지 않는 것이면 특별히 제한되지 않는다. 특히, 무기물 입자로서 유전율이 높은 무기물 입자를 사용하는 경우, 액체 전해질 내 전해질 염, 예컨대 리튬염의 해리도 증가에 기여하여 전해액의 이온 전도도를 향상시킬 수 있다.In addition, the inorganic particles that can be used in the present invention are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles that can be used in the present invention are not particularly limited as long as the oxidation and / or reduction reactions do not occur in the operating voltage range (for example, 0 to 5 V on the basis of Li / Li + ) of the applied electrochemical device. In particular, when inorganic particles having a high dielectric constant are used as the inorganic particles, the ionic conductivity of the electrolyte may be improved by contributing to an increase in the dissociation degree of the electrolyte salt, such as lithium salt, in the liquid electrolyte.
전술한 이유들로 인해, 상기 무기물 입자는 유전율 상수가 5 이상, 또는 10 이상인 고유전율 무기물 입자를 포함할 수 있다. 유전율 상수가 5 이상인 무기물 입자의 비제한적인 예로는 BaTiO3, Pb(Zrx, Ti1-x)O3(PZT, 여기서, 0<x<1임), Pb1-xLaxZr1-yTiyO3(PLZT, 여기서, 0 < x < 1, 0 < y < 1임), (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-PT, 여기서, 0 < x < 1), 하프니아(HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, SiC, SiO2, AlOOH, Al(OH)3 및 TiO2로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있다.For the foregoing reasons, the inorganic particles may include high dielectric constant inorganic particles having a dielectric constant of 5 or more, or 10 or more. Non-limiting examples of inorganic particles having a dielectric constant of 5 or more include BaTiO 3 , Pb (Zr x , Ti 1-x ) O 3 (PZT, where 0 <x <1), Pb 1-x La x Zr 1- y Ti y O 3 (PLZT, where 0 <x <1, 0 <y <1), (1-x) Pb (Mg 1/3 Nb 2/3 ) O 3 -xPbTiO 3 (PMN-PT, Where 0 <x <1), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , SiC, SiO 2 , AlOOH, Al (OH) 3 and TiO 2 may be any one selected from the group consisting of or a mixture of two or more thereof.
또한, 상기 무기물 입자로는 리튬 이온 전달 능력을 갖는 무기물 입자, 즉 리튬 원소를 함유하되 리튬을 저장하지 아니하고 리튬 이온을 이동시키는 기능을 갖는 무기물 입자를 사용할 수 있다. 리튬 이온 전달 능력을 갖는 무기물 입자의 비제한적인 예로는 리튬 포스페이트(Li3PO4), 리튬 티타늄 포스페이트(LixTiy(PO4)3, 0 < x < 2, 0 < y < 3), 리튬 알루미늄 티타늄 포스페이트(LixAlyTiz(PO4)3, 0 < x < 2, 0 < y < 1, 0 < z < 3), 14Li2O-9Al2O3-38TiO2-39P2O5 등과 같은 (LiAlTiP)xOy 계열 글래스(0 < x < 4, 0 < y < 13), 리튬 란탄 티타네이트(LixLayTiO3, 0 < x < 2, 0 < y < 3), Li3.25Ge0.25P0.75S4 등과 같은 리튬 게르마니움 티오포스페이트(LixGeyPzSw, 0 < x < 4, 0 < y < 1, 0 < z < 1, 0 < w < 5), Li3N 등과 같은 리튬 나이트라이드(LixNy, 0 < x < 4, 0 < y < 2), Li3PO4-Li2S-SiS2 등과 같은 SiS2 계열 글래스(LixSiySz, 0 < x < 3, 0 < y < 2, 0 < z < 4), LiI-Li2S-P2S5 등과 같은 P2S5 계열 글래스(LixPySz, 0 < x < 3, 0 < y < 3, 0 < z < 7) 또는 이들의 혼합물 등이 있다.In addition, the inorganic particles may be used as inorganic particles having a lithium ion transfer ability, that is, inorganic particles containing a lithium element, but having a function of moving lithium ions without storing lithium. Non-limiting examples of inorganic particles having a lithium ion transfer capacity include lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li x Ti y (PO 4 ) 3 , 0 <x <2, 0 <y <3), Lithium aluminum titanium phosphate (Li x Al y Ti z (PO 4 ) 3 , 0 <x <2, 0 <y <1, 0 <z <3), 14Li 2 O-9Al 2 O 3 -38TiO 2 -39P 2 (LiAlTiP) x O y series glasses such as O 5 (0 <x <4, 0 <y <13), lithium lanthanum titanate (Li x La y TiO 3 , 0 <x <2, 0 <y <3) , Li germanium thiophosphate, such as Li 3.25 Ge 0.25 P 0.75 S 4 (Li x Ge y P z S w , 0 <x <4, 0 <y <1, 0 <z <1, 0 <w <5 ), Li nitrides such as Li 3 N (Li x N y , 0 <x <4, 0 <y <2), SiS 2 series glasses such as Li 3 PO 4 -Li 2 S-SiS 2 (Li x Si P 2 S 5 series glass (Li x P y S z , 0 <x) such as y S z , 0 <x <3, 0 <y <2, 0 <z <4), LiI-Li 2 SP 2 S 5, etc. <3, 0 <y <3, 0 <z <7) or mixtures thereof.
상기 무기물 입자의 크기는 제한이 없으나, 다공성 코팅층의 적절한 기공도를 위해, 평균 입경이 10 nm 내지 5 ㎛일 수 있다.The size of the inorganic particles is not limited, but for proper porosity of the porous coating layer, the average particle diameter may be 10 nm to 5 ㎛.
그리고, 상기 제2 고분자 바인더는, 폴리비닐리덴 풀루오라이드 (polyvinylidene fluoride, PVDF), 헥사풀루오로프로필렌 (hexafluoro propylene, HFP), 폴리비닐리덴 풀루오라이드-헥사풀루오로프로필렌 (polyvinylidene fluoride-co-hexafluoro propylene), 폴리비닐리덴 풀루오라이드-트리클로로에틸렌(polyvinylidene fluoride-co-trichloroethylene), 폴리메틸 메타크릴레이트 (polymethyl methacrylate), 폴리아크릴로니트릴 (polyacrylonitrile), 폴리비닐피롤리돈 (polyvinylpyrrolidone), 폴리비닐아세테이트 (polyvinylacetate), 에틸렌 비닐 아세테이트 공중합체 (polyethylene-co-vinyl acetate), 폴리에틸렌 옥사이드 (polyethylene oxide), 폴리아릴레이트 (polyarylate), 셀룰로오스 아세테이트 (cellulose acetate), 셀룰로오스 아세테이트 부틸레이트 (cellulose acetate butyrate), 셀룰로오스 아세테이트 프로피오네이트 (cellulose acetate propionate), 시아노에틸풀루란 (cyanoethylpullulan), 시아노에틸폴리비닐알콜 (cyanoethylpolyvinylalcohol), 시아노에틸셀룰로오스 (cyanoethylcellulose), 시아노에틸수크로오스 (cyanoethylsucrose), 풀루란 (pullulan), 카르복실 메틸 셀룰로오스 (carboxyl methyl cellulose), 스티렌부타디엔 고무 (styrene-butadiene rubber), 아크릴로니트릴스티렌부타디엔 공중합체 (acrylonitrile-styrene-butadiene copolymer) 및 폴리이미드 (polyimide)로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물일 수 있으나, 이에만 한정하는 것은 아니다.The second polymer binder may be polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafulopropylene (polyvinylidene fluoride-) co-hexafluoro propylene), polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone ), Polyvinylacetate, ethylene vinyl co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butylate acetate butyrate), cellulose acetate propionate, Cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose , Styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer (acrylonitrile-styrene-butadiene copolymer) and polyimide may be any one or a mixture of two or more thereof. It is not limited only to this.
한편, 상기 집전체는, 스테인리스스틸, 알루미늄, 니켈, 티탄, 소성탄소, 구리; 카본, 니켈, 티탄 또는 은으로 표면처리된 스테인리스스틸; 알루미늄-카드뮴합금; 도전재로 표면처리된 비전도성 고분자; 또는 전도성 고분자로 제조된 것이 바람직하며, 상기 열린 구조의 외부집전체는, 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 것이 바람직하다.On the other hand, the current collector, stainless steel, aluminum, nickel, titanium, calcined carbon, copper; Stainless steel surface-treated with carbon, nickel, titanium, or silver; Aluminum-cadmium alloys; Non-conductive polymer surface-treated with a conductive material; Or it is preferably made of a conductive polymer, the outer current collector of the open structure, stainless steel, aluminum, nickel, titanium, calcined carbon, copper; Stainless steel surface-treated with carbon, nickel, titanium, or silver; Aluminum-cadmium alloys; Non-conductive polymer surface-treated with a conductive material; Conductive polymers; A metal paste comprising a metal powder of Ni, Al, Au, Ag, Al, Pd / Ag, Cr, Ta, Cu, Ba, or ITO; Or a carbon paste containing carbon powder which is graphite, carbon black or carbon nanotubes.
집전체는 전극 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 collects electrons generated by the electrochemical reaction of the electrode active material or serves to supply electrons required for the electrochemical reaction. Generally, a metal such as copper or aluminum is used. In particular, in the case of using a non-conductive polymer surface-treated as a conductive material or a polymer conductor made of a conductive polymer, it is relatively more flexible than using a metal such as copper or aluminum. In addition, it is possible to achieve the light weight of the battery by using a polymer current collector in place of the metal current collector.
이러한 도전재로는 폴리아세틸렌, 폴리아닐린, 폴리피롤, 폴리티오펜, 폴리설퍼니트리드, ITO(Indum Thin Oxide), 은, 팔라듐 및 니켈 등이 가능하며, 전도성 고분자는 폴리아세틸렌, 폴리아닐린, 폴리피롤, 폴리티오펜 및 폴리설퍼니트리드 등이 사용 가능하다. 다만, 집전체에 사용되는 비전도성 고분자는 특별히 종류를 한정하지는 않는다.Such conductive materials may be polyacetylene, polyaniline, polypyrrole, polythiophene, polysulfuride, ITO (Indum Thin Oxide), silver, palladium and nickel, and the conductive polymer may be polyacetylene, polyaniline, polypyrrole, polythiol Offen, polysulfuritride and the like can be used. However, the non-conductive polymer used for the current collector is not particularly limited in kind.
그리고, 상기 이차전지용 전극은, 음극일 수 있으며, 이때 상기 전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx);로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함할 수 있다.In addition, the secondary battery electrode may be a negative electrode, wherein the electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Metals (Me) which are Cu, Co, Ni or Fe; Alloys composed of the metals (Me); And an oxide (MeOx) of the metals (Me); any one active material particles selected from the group consisting of or a mixture of two or more thereof.
본 발명의 전극 활물질층은 집전체를 통해서 이온을 이동시키는 작용을 하고, 이들 이온의 이동은 전해질층으로부터의 이온의 흡장 및 전해질층으로의 이온의 방출을 통한 상호작용에 의한다.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 occlusion of ions from the electrolyte layer and release of ions into the electrolyte layer.
한편, 본 발명의 이차전지는, 양극, 음극, 상기 양극과 상기 음극의 사이에 개재되는 세퍼레이터, 및 비수전해액을 포함하는 것으로서, 상기 음극은 본 발명의 이차전지용 전극이다.On the other hand, the secondary battery of the present invention includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte, the negative electrode is the secondary battery electrode of the present invention.
여기서 본 발명의 이차전지는, 스택형, 권취형, 스택/폴딩형의 일반적인 형태의 이차전지뿐만 아니라, 케이블형 이차전지 등의 특수한 형태의 이차전지일 수 있다.Here, the secondary battery of the present invention may be a secondary battery of a special type such as a cable type secondary battery as well as a secondary battery of a general type of a stack type, a winding type, a stack / folding type.
더욱 구체적으로는, 본 발명의 일 측면에 따른 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지는, 전해질을 포함하는 리튬이온 공급 코어부; 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 내부전극; 상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함한다.More specifically, the cable-type secondary battery having a horizontal cross section according to an aspect of the present invention extending in the longitudinal direction, the lithium ion supply core portion containing an electrolyte; An internal current collector having an open structure formed around an outer surface of the lithium ion supply core part, an internal electrode active material layer formed on an outer surface of the internal current collector, and an outer surface of the internal electrode active material layer, and formed of graphite, a conductive material, and a first polymer An internal electrode having a graphite coating layer including a binder, and a porous coating layer formed on an outer surface of the graphite coating layer and including a second polymer binder; A separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode; And an external electrode formed surrounding the outer surface of the separation layer and having an external current collector and an external electrode active material layer.
이때, 열린 구조라 함은 그 열린 구조를 경계면으로 하고, 이러한 경계면을 통과하여 내부에서 외부로의 물질의 이동이 자유로운 형태의 구조를 말하는 것이며, 상기 열린 구조의 외부집전체는, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체일 수 있으나, 이에만 한정하는 것은 아니다.In this case, the open structure refers to a structure in which the open structure is a boundary surface, and a structure in which material moves from inside to outside through this boundary surface is free, and the outer current collector of the open structure is a wound wire-type house. It may be a whole, a wound sheet current collector or a mesh current collector, but is not limited thereto.
그리고, 상기 수평 단면은 원형 또는 다각형일 수 있는데, 원형은 기하학적으로 완전한 대칭형의 원형과 비대칭형의 타원형 구조이다. 다각형은 2차원의 시트형이 아닌 구조라면 특별히 제한되는 것은 아니고, 이러한 다각형 구조의 비제한적인 예로는 삼각형, 사각형, 오각형 또는 육각형 등이 있다.And, the horizontal cross section may be circular or polygonal, which is a geometrically perfect symmetrical circular and asymmetrical oval structure. The polygon is not particularly limited as long as it is not a two-dimensional sheet-like structure. Non-limiting examples of the polygonal structure include triangles, squares, pentagons, and hexagons.
그리고, 상기 다공성 코팅층은, 전술한 바와 같이 무기물 입자를 더 포함할 수 있다.The porous coating layer may further include inorganic particles as described above.
여기서, 상기 내부전극은 음극이며, 상기 내부전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx);로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것일 수 있다.Here, the internal electrode is a cathode, the internal electrode active material layer is Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Metals such as Ni or Fe (Me); Alloys composed of the metals (Me); And oxides (MeOx) of the metals (Me); any one of the active material particles selected from the group consisting of, or a mixture of two or more thereof.
이때, 상기 외부전극은 양극이며, 상기 외부전극 활물질층은 양극 활물질로서, LiCoO2, LiNiO2, LiMn2O4, LiCoPO4, LiFePO4, LiNiMnCoO2 및 LiNi 1-x-y-zCoxM1yM2zO2(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)로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함할 수 있다.At this time, the external electrode is a positive electrode, the external electrode active material layer is a positive electrode active material, 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 independently from each other Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo is any one selected from the group, x, y and z are independently of each other An active material particle selected from the group consisting of 0 ≦ x <0.5, 0 ≦ y <0.5, 0 ≦ z <0.5, and x + y + z ≦ 1 as an atomic fraction of oxide composition elements, or two or more thereof Mixtures may be included.
본 발명의 케이블형 이차전지는 수평 단면을 가지며, 수평 단면에 대한 길이방향으로 길게 늘어진 선형구조를 갖고, 가요성을 가지므로 변형이 자유롭다.The cable type secondary battery of the present invention has a horizontal cross section, has a linear structure elongated in the longitudinal direction with respect to the horizontal cross section, and has flexibility, and thus deformation is free.
도 3은 본 발명의 일 실시예에 따른, 하나의 내부전극을 포함하는 케이블형 이차전지의 사시도를 나타낸 도면이다.3 is a perspective view of a cable type secondary battery including one internal electrode according to an embodiment of the present invention.
도 3을 참조하면, 케이블형 이차전지(100)는, 전해질을 포함하는 리튬이온 공급 코어부(110); 상기 리튬이온 공급 코어부(110)의 외면을 둘러싸며 형성된 열린 구조의 내부집전체(120), 상기 내부집전체(120)의 외면에 형성된 내부전극 활물질층(130), 상기 내부전극 활물질층(130)의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층(131), 및 상기 흑연계 코팅층(131)의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층(132)을 구비하는 내부전극; 상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층(140); 및 상기 분리층(140)의 외면을 둘러싸며 형성된 외부전극 활물질층(150) 및 상기 외부전극 활물질층(150)의 외면을 둘러싸며 형성된 외부집전체(160)를 구비하는 외부전극;을 포함할 수 있다.Referring to FIG. 3, the cable type secondary battery 100 may include a lithium ion supply core unit 110 including an electrolyte; An internal current collector 120 having an open structure formed surrounding the outer surface of the lithium ion supply core unit 110, an internal electrode active material layer 130 formed on an outer surface of the internal current collector 120, and the internal electrode active material layer ( It is formed on the outer surface of 130, a graphite coating layer 131 including graphite, a conductive material and a first polymer binder, and a porous coating layer formed on the outer surface of the graphite coating layer 131, and including a second polymer binder An internal electrode having 132; Separation layer 140 to prevent the short circuit of the electrode formed surrounding the outer surface of the inner electrode; And an external electrode including an external electrode active material layer 150 formed surrounding the outer surface of the separation layer 140 and an external current collector 160 formed surrounding the outer surface of the external electrode active material layer 150. Can be.
상기 구조 외에도, 상기 외부전극은, 외부집전체와 외부전극 활물질층의 위치에 따라 다양한 구조가 가능한데, 상기 분리층의 외면을 둘러싸며 형성된 외부집전체 및 상기 외부집전체의 외면을 둘러싸며 형성된 외부전극 활물질층을 구비하는 구조; 상기 분리층의 외면을 둘러싸며 형성된 외부집전체 및 상기 외부집전체의 외면을 둘러싸며 상기 분리층과 접촉하도록 형성된 외부전극 활물질층을 구비하는 구조; 상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층 및 상기 외부전극 활물질층 내에 피복되어 있고, 상기 분리층의 외면을 이격된 상태로 둘러싸며 형성된 외부집전체를 구비하는 구조; 등이 가능하다.In addition to the above structure, the external electrode may have various structures according to the positions of the external current collector and the external electrode active material layer, the external current collector formed to surround the outer surface of the separation layer and the external current formed to surround the external surface of the external current collector. A structure including an electrode active material layer; A structure including an outer current collector formed to surround the outer surface of the separation layer and an outer electrode active material layer formed to contact the separation layer and surrounding the outer surface of the outer current collector; A structure including an outer electrode active material layer formed surrounding the outer surface of the separation layer and an outer current collector covered in the outer electrode active material layer and surrounding the outer surface of the separation layer in a spaced state; Etc. are possible.
한편, 본 발명의 다른 측면에 따른 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지는, 전해질을 포함하는 리튬이온 공급 코어부; 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체 및 상기 내부집전체의 외면에 형성된 내부전극 활물질층을 구비하는 내부전극; 상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함한다.On the other hand, the cable-type secondary battery extending in the longitudinal direction with a horizontal cross-section according to another aspect of the present invention, a lithium ion supply core portion containing an electrolyte; An inner electrode including an inner current collector having an open structure formed around an outer surface of the lithium ion supply core and an inner electrode active material layer formed on an outer surface of the inner current collector; A separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode; And a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. An external electrode;
여기서, 상기 다공성 코팅층은, 전술한 바와 같이 무기물 입자를 더 포함할 수 있다.Here, the porous coating layer may further include inorganic particles as described above.
이때, 상기 외부전극은 음극이며, 상기 외부전극 활물질층은, 음극 활물질을 포함하는 것으로서, 전술한 바와 같다.In this case, the external electrode is a negative electrode, and the external electrode active material layer includes a negative electrode active material, as described above.
도 4는 본 발명의 일 실시예에 따른, 외부전극에 흑연계 코팅층 및 다공성 코팅층이 형성된 케이블형 이차전지의 사시도를 나타낸 도면이다.4 is a diagram illustrating a perspective view of a cable type secondary battery in which a graphite-based coating layer and a porous coating layer are formed on an external electrode, according to an embodiment of the present invention.
도 4를 참조하면, 케이블형 이차전지(200)는, 전해질을 포함하는 리튬이온 공급 코어부(210); 상기 리튬이온 공급 코어부(210)의 외면을 둘러싸며 형성된 열린 구조의 내부집전체(220) 및 상기 내부집전체(220)의 외면에 형성된 내부전극 활물질층(230)을 구비하는 내부전극; 상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층(240); 및 상기 분리층(240)의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층(252), 상기 다공성 코팅층(252)의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층(251), 상기 흑연계 코팅층(251)의 외면을 둘러싸며 형성된 외부전극 활물질층(250) 및 상기 외부전극 활물질층(250)의 외면을 둘러싸며 형성된 외부집전체(260)를 구비하는 외부전극;을 포함할 수 있다.Referring to FIG. 4, the cable type secondary battery 200 may include a lithium ion supply core unit 210 including an electrolyte; An inner electrode including an inner current collector 220 having an open structure formed around the outer surface of the lithium ion supply core unit 210 and an inner electrode active material layer 230 formed on an outer surface of the inner current collector 220; A separation layer 240 surrounding the outer surface of the inner electrode to prevent a short circuit of the electrode; And a porous coating layer 252 formed around the outer surface of the separation layer 240 and surrounding the outer surface of the porous coating layer 252 including a second polymer binder, graphite, a conductive material, and a first polymer. Graphite coating layer 251 including a binder, an external electrode active material layer 250 formed surrounding the outer surface of the graphite coating layer 251 and an external current collector formed surrounding the outer surface of the external electrode active material layer 250 ( It may include an external electrode having a 260.
상기 구조 외에도, 상기 외부전극은, 상기 도전재 코팅층과 상기 다공성 코팅층의 위치에 따라 다양한 구조가 가능한데, 상기 분리층의 외면을 둘러싸며 형성된 외부집전체, 상기 외부집전체의 외면을 둘러싸며 형성된 외부전극 활물질층, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 구조; 상기 분리층의 외면을 둘러싸며 형성된 외부집전체, 상기 외부집전체의 외면을 둘러싸며 상기 분리층과 접촉하도록 형성된 외부전극 활물질층, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 구조; 또는 상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층, 상기 외부전극 활물질층 내에 피복되어 있고, 상기 분리층의 외면을 이격된 상태로 둘러싸며 형성된 외부집전체, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 구조; 등이 가능하다.In addition to the structure, the external electrode may be a variety of structures depending on the position of the conductive material coating layer and the porous coating layer, the outer current collector formed surrounding the outer surface of the separation layer, the outer formed around the outer surface of the outer current collector It is formed surrounding the outer surface of the electrode active material layer, the outer electrode active material layer, the graphite-based coating layer including graphite, a conductive material and the first polymer binder, and formed to surround the outer surface of the graphite-based coating layer, the second polymer binder A structure having a porous coating layer comprising a; An outer current collector formed to surround the outer surface of the separation layer, an outer electrode active material layer formed to contact the separation layer and surrounding the outer surface of the outer current collector, formed to surround the outer surface of the outer electrode active material layer, graphite, conductive A structure comprising a graphite coating layer comprising ash and a first polymer binder, and a porous coating layer formed surrounding the outer surface of the graphite coating layer and including a second polymer binder; Or an outer electrode active material layer formed surrounding the outer surface of the separation layer, the outer current collector covered with the outer electrode active material layer and surrounded by an outer surface of the separation layer, and an outer surface of the outer electrode active material layer. A structure comprising a graphite coating layer surrounding and formed surrounding the outer surface of the graphite coating layer, the graphite coating layer including graphite, a conductive material, and a first polymer binder, the porous coating layer including a second polymer binder; Etc. are possible.
한편, 본 발명의 분리층은, 전해질층 또는 세퍼레이터를 사용할 수 있다.In addition, an electrolyte layer or a separator can be used for the separation layer of this invention.
이온의 통로가 되는 전해질층으로는 PEO, PVdF, PVdF-HFP, 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.Examples of the electrolyte layer serving as an ion passage include a gel polymer electrolyte using PEO, PVdF, PVdF-HFP, PMMA, PAN, or PVAC; Or a solid electrolyte using PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES) or polyvinyl acetate (PVAc); Etc. The matrix of the solid electrolyte is preferably made of polymer or ceramic glass as a basic skeleton. In the case of a general polymer electrolyte, even if the ion conductivity is satisfied, ions may move very slowly in terms of reaction rate, and therefore, it is preferable to use an electrolyte of a gel polymer having easier movement of ions than a solid. Since the gel polymer electrolyte is not excellent in mechanical properties, it may include a pore structure support or a crosslinked polymer 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, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, 클로로보란리튬, 저급지방족카르본산리튬 및 테트라페닐붕산리튬 등을 사용할 수 있다.The electrolyte layer of the present invention may further include a lithium salt. Lithium salts can improve ionic conductivity and reaction rate, non-limiting examples of which are 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 available borane lithium, lower aliphatic carboxylic acid lithium, and tetraphenyl lithium borate, etc. have.
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 고분자 기재; 폴리에스테르, 폴리아세탈, 폴리아미드, 폴리카보네이트, 폴리이미드, 폴리에테르에테르케톤, 폴리에테르설폰, 폴리페닐렌옥사이드, 폴리페닐렌설파이트 및 폴리에틸렌나프탈렌으로 이루어진 군에서 선택된 고분자로 제조한 다공성 고분자 기재; 또는 무기물 입자 및 바인더 고분자의 혼합물로 형성된 다공성 고분자 기재 등을 사용할 수 있다.The separator is not limited to a kind thereof, but a porous material 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. A polymer substrate; A porous polymer 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 polymer substrate formed of a mixture of inorganic particles and a binder polymer may be used.
그리고, 본 발명은 보호피복을 구비하는데, 보호피복은 절연체로서 공기 중의 수분 및 외부충격에 대하여 전극을 보호하기 위해 외부전극의 외면에 형성한다. 보호피복으로는 통상의 고분자 수지를 사용할 수 있으며, 일례로 PVC, HDPE 또는 에폭시 수지가 사용 가능하다.In addition, the present invention includes a protective coating, which is formed on the outer surface of the external electrode to protect the electrode against moisture and external shock in the air as an insulator. As the protective coating, a conventional polymer resin can be used. For example, PVC, HDPE or epoxy resin can be used.
한편, 본 발명의 다른 실시예로서의 케이블형 이차전지는, 2개 이상의 내부전극을 포함한다.On the other hand, the cable type secondary battery according to another embodiment of the present invention includes two or more internal electrodes.
여기서, 상기 내부전극이 음극인 경우에는, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하거나, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층 및 상기 다공성 코팅층의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 및 상기 내부전극들의 외면을 함께 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함한다.Here, when the internal electrode is a cathode, at least two lithium ion supply core portion containing an electrolyte; An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer; At least two internal electrodes formed on the outer surface of the graphite coating layer including one polymer binder and formed on an outer surface of the graphite coating layer, and having a porous coating layer including a second polymer binder; A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And an external electrode formed surrounding the outer surface of the separation layer, the external electrode including an external current collector and an external electrode active material layer, or two or more lithium ion supply core parts including an electrolyte; An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer; A graphite-based coating layer comprising a polymer binder, a porous coating layer formed on the outer surface of the graphite-based coating layer, and a separation layer for preventing a short circuit of the electrode formed surrounding the outer surface of the porous coating layer; Two or more internal electrodes disposed in parallel to each other; And an outer electrode formed to surround the outer surfaces of the inner electrodes and having an outer current collector and an outer electrode active material layer.
이때, 상기 다공성 코팅층은, 전술한 바와 같이 무기물 입자를 더 포함할 수 있다.In this case, the porous coating layer may further include inorganic particles as described above.
이하, 구체적으로 도 5를 참조하여 설명한다.Hereinafter, a detailed description will be given with reference to FIG. 5.
도 5를 참조하면, 본 발명의 다수의 내부전극을 포함하는 케이블형 이차전지(300)는, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부(310); 각각의 상기 리튬이온 공급 코어부(310)의 외면을 둘러싸며 형성된 열린 구조의 내부집전체(320), 상기 내부집전체(320)의 외면에 형성된 내부전극 활물질층(330), 상기 내부전극 활물질층(330)의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층(331), 및 상기 흑연계 코팅층(331)의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층(332)을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층(340); 및 상기 분리층(340)의 외면을 둘러싸며 형성된 외부전극 활물질층(350), 상기 외부전극 활물질층(350)의 외면을 둘러싸며 형성된 외부집전체(360)를 구비하는 외부전극;을 포함한다.Referring to FIG. 5, a cable type secondary battery 300 including a plurality of internal electrodes of the present invention includes two or more lithium ion supply core portions 310 including an electrolyte; An inner current collector 320 having an open structure formed around an outer surface of each of the lithium ion supply cores 310, an inner electrode active material layer 330 formed on an outer surface of the inner current collector 320, and the inner electrode active material It is formed on the outer surface of the layer 330, the graphite-based coating layer 331 including graphite, a conductive material and the first polymer binder, and formed on the outer surface of the graphite-based coating layer 331, and comprises a second polymer binder Two or more internal electrodes disposed in parallel with each other having the porous coating layer 332; A separation layer 340 surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And an external electrode including an external electrode active material layer 350 formed to surround the outer surface of the separation layer 340, and an external current collector 360 formed to surround the outer surface of the external electrode active material layer 350. .
그리고, 상기 외부전극이 음극인 경우에는, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체 및 상기 내부집전체의 외면을 둘러싸며 형성된 내부전극 활물질층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및 상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하거나, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부; 각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면을 둘러싸며 형성된 내부전극 활물질층 및 상기 내부전극 활물질층의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 및 상기 내부전극들의 외면을 함께 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함한다.And, when the external electrode is a negative electrode, two or more lithium ion supply core portion containing an electrolyte; Two or more internal electrodes disposed in parallel with each other including an inner current collector having an open structure formed around an outer surface of each lithium ion supply core and an inner electrode active material layer formed surrounding the outer surface of the inner current collector; A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And a porous coating layer formed surrounding the outer surface of the separation layer, the graphite-based coating layer including an external current collector, an external electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. An external electrode; or two or more lithium ion supply core parts including an electrolyte; An inner current collector having an open structure formed surrounding the outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed surrounding the outer surface of the inner current collector, and a short circuit of the electrode formed surrounding the outer surface of the inner electrode active material layer Two or more internal electrodes disposed in parallel with each other having a separation layer for preventing; And a porous coating layer formed to surround the outer surfaces of the inner electrodes, the graphite-based coating layer including an outer current collector, an outer electrode active material layer, graphite, a conductive material, and a first polymer binder, and a second polymer binder. It includes; an external electrode.
이때, 상기 다공성 코팅층은, 전술한 바와 같이 무기물 입자를 더 포함할 수 있다.In this case, the porous coating layer may further include inorganic particles as described above.
이하, 구체적으로 도 6을 참조하여 설명한다.Hereinafter, a detailed description will be given with reference to FIG. 6.
도 6을 참조하면, 전해질을 포함하는 2 이상의 리튬이온 공급 코어부(410); 각각의 상기 리튬이온 공급 코어부(410)의 외면을 둘러싸며 형성된 열린 구조의 내부집전체(420) 및 상기 내부집전체(420)의 외면을 둘러싸며 형성된 내부전극 활물질층(430)을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층(440); 및 상기 분리층(440)의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층(452), 상기 다공성 코팅층(452)의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층(451), 상기 흑연계 코팅층(451)의 외면을 둘러싸며 형성된 외부전극 활물질층(450) 및 상기 외부전극 활물질층(450)의 외면을 둘러싸며 형성된 외부집전체(460)를 구비하는 외부전극;을 포함한다.6, at least two lithium ion supply core portions 410 including an electrolyte; An inner current collector 420 having an open structure formed surrounding the outer surface of each lithium ion supply core unit 410 and an inner electrode active material layer 430 formed surrounding the outer surface of the inner current collector 420. Two or more internal electrodes disposed in parallel to each other; A separation layer 440 which surrounds the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And a porous coating layer 452 formed surrounding the outer surface of the separation layer 440 and surrounding the outer surface of the porous coating layer 452 including a second polymer binder, graphite, a conductive material, and a first polymer. Graphite coating layer 451 including a binder, an external electrode active material layer 450 formed surrounding the outer surface of the graphite coating layer 451 and an external current collector formed surrounding the outer surface of the external electrode active material layer 450 ( It includes; an external electrode having a 460.
여기서 제시한 외부전극의 형성모습 외에도 더 가능한 구체적인 모습은 전술한 바와 같다.In addition to the formation of the external electrode presented here, a more specific shape is as described above.
이러한 케이블형 이차전지(300, 400)는 복수의 전극으로 이루어진 내부전극을 구비하므로, 음극과 양극의 밸런스 조정이 용이하고 다수의 전극을 구비하므로 단선의 가능성을 방지할 수 있다.Since the cable type secondary batteries 300 and 400 have internal electrodes formed of a plurality of electrodes, the balance between the negative electrode and the positive electrode can be easily adjusted, and the plurality of electrodes can be prevented, thereby preventing the possibility of disconnection.
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 안 된다. 본 발명의 실시예는 당업계에서 평균적인 지식을 가진 자에게 본 발명을 보다 완전하게 설명하기 위해서 제공되는 것이다.Hereinafter, the present invention will be described in detail with reference to Examples. However, embodiments according to the present invention can be modified in many different forms, the scope of the present invention should not be construed as limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.
실시예Example
(1) 전극의 제조(1) Preparation of the electrode
전기도금법을 이용하여, 지름이 125 ㎛인 와이어형 구리 집전체에, 두께가 2.5 ㎛인 니켈과 주석을 포함하는 전극 활물질을 코팅하여, 전극 활물질층을 형성하였다.Using an electroplating method, an electrode active material containing nickel and tin having a thickness of 2.5 μm was coated on a wire-type copper current collector having a diameter of 125 μm to form an electrode active material layer.
그 후, 천연흑연, 도전재 및 제1 고분자 바인더로서 폴리비닐리덴 풀루오라이드가, 70 : 5 : 25의 중량비로 혼합된 혼합물을, N-메틸 피롤리돈의 용매에 혼합하여 슬러리를 제조하였고, 상기 슬러리를 상기 전극 활물질층의 외면 전체에 코팅하여 흑연계 코팅층을 형성하였다.Then, a slurry was prepared by mixing a mixture of natural graphite, a conductive material, and polyvinylidene fluoride as a first polymer binder in a weight ratio of 70: 5: 25 in a solvent of N-methyl pyrrolidone. The slurry was coated on the entire outer surface of the electrode active material layer to form a graphite coating layer.
도 7은 상기 흑연계 코팅층이 형성된 와이어형 전극의 형상을 나타낸 SEM 사진이다.7 is a SEM photograph showing the shape of the wire type electrode on which the graphite coating layer is formed.
이어서, 무기물 입자로서 산화규소(SiO2)와, 제2 고분자 바인더로서 폴리비닐리덴풀루오라이드-헥사풀루오로프로필렌 공중합체(PVdF-HFP5%)가, 10 : 90의 중량비로 혼합된 혼합물을, 아세톤 용매에, 6 %의 중량비가 되도록 혼합하여 용액을 제조하였다.Next, a mixture of silicon oxide (SiO 2 ) as inorganic particles and polyvinylidene fluoride-hexafuluropropylene copolymer (PVdF-HFP5%) as a second polymer binder was mixed at a weight ratio of 10:90. , Was mixed with an acetone solvent in a weight ratio of 6% to prepare a solution.
상기 제조된 용액에 비용매로서 물을, 전체 용액의 5 중량%로 혼합하였다. 이렇게 준비된 용액을 상기 흑연계 코팅층의 외면 전체에 코팅하여 상온에서 아세톤 용매를 증발시킨 후, 진공오븐에 100 ℃의 온도에서 10 시간 건조하여 다공성 코팅층을 형성하였다.To the solution prepared above was mixed water as a nonsolvent at 5% by weight of the total solution. The solution thus prepared was coated on the entire outer surface of the graphite coating layer to evaporate the acetone solvent at room temperature, and then dried in a vacuum oven at a temperature of 100 ° C. for 10 hours to form a porous coating layer.
도 8은 이러한 과정에 의해 형성된 다공성 코팅층의 형상을 나타낸 SEM 사진이다.Figure 8 is a SEM photograph showing the shape of the porous coating layer formed by this process.
(2) 코인형 반쪽 전지의 제조(2) Preparation of coin type half cell
상기 실시예 (1)에서 제조된 와이어형 전극을, 수평한 면상에서 권취함으로써 판형의 모양이 되도록 제작하여, 이를 음극으로 사용하고, 양극으로는 금속 리튬 호일을 사용하였으며, 상기 양극과 음극 사이에 폴리에틸렌 세퍼레이터를 개재하여 전극 조립체를 제조하였다.The wire-shaped electrode prepared in Example (1) was manufactured to be in the shape of a plate by winding on a horizontal plane, and used as a cathode, and a metal lithium foil was used as a cathode, between the anode and the cathode. An electrode assembly was produced via a polyethylene separator.
상기 전극 조립체를 전지 케이스에 넣은 후, 에틸렌 카보네이트(EC)와 디에틸 카보네이트(DEC)의 부피비가 1:2로 혼합된 비수 용매에 1M의 LiPF6가 첨가된 전해액을 주입하여 코인형 반쪽 전지를 제조하였다.After the electrode assembly was placed in a battery case, 1M LiPF 6 was added to a nonaqueous solvent in which a volume ratio of ethylene carbonate (EC) and diethyl carbonate (DEC) was mixed at a ratio of 1: 2. Prepared.
비교예Comparative example
(1) 전극의 제조(1) Preparation of the electrode
전기도금법을 이용하여, 지름이 125 ㎛인 와이어형 구리 집전체에, 두께가 2.5 ㎛인 니켈과 주석을 포함하는 전극 활물질을 코팅하여, 전극 활물질층을 형성하였다.Using an electroplating method, an electrode active material containing nickel and tin having a thickness of 2.5 μm was coated on a wire-type copper current collector having a diameter of 125 μm to form an electrode active material layer.
(2) 코인형 반쪽 전지의 제조(2) Preparation of coin type half cell
비교예 (1)에서 제조된 와이어형 전극을, 수평한 면상에서 권취함으로써 판형의 모양이 되도록 제작하여, 이를 음극으로 사용하는 것을 제외하고는 실시예 (2)와 동일한 방법으로 코인형 반쪽 전지를 제조하였다.A coin-type half cell was manufactured in the same manner as in Example (2) except that the wire-shaped electrode prepared in Comparative Example (1) was manufactured to be in a plate shape by winding on a horizontal plane, and then used as a negative electrode. Prepared.
충방전 특성 평가Charge / discharge characteristic evaluation
상기 실시예 및 비교예에서 제조된 코인형 반쪽 전지를 이용하여 충방전 특성을 평가하였다.Charge-discharge characteristics were evaluated using the coin-type half cells prepared in the examples and comparative examples.
충전지 0.1 C의 전류밀도로 5 mV까지 정전류 충전 후, 정전압으로 5 mV로 일정하게 유지시켜 전류밀도가 0.005 C가 되면 충전을 종료하였다. 방전시 0.5 C의 전류밀도로 1.5 V까지 정전류 모드로 방전을 완료하였다. 동일한 조건으로 충방전을 30회 반복하였다.After the constant current was charged to 5 mV at a current density of 0.1 C of the rechargeable battery, the charge was kept constant at 5 mV at a constant voltage, and the charge was terminated when the current density became 0.005 C. The discharge was completed in the constant current mode up to 1.5 V at a current density of 0.5 C. Charge and discharge were repeated 30 times under the same conditions.
도 9는 실시예와 비교예에서 제조된 전지를 이용하여 관측된 충방전 프로파일을 방전 용량에 대해 정규화하여 나타낸 그래프이다.9 is a graph showing normalized charging and discharging profiles with respect to discharge capacity using the batteries manufactured in Examples and Comparative Examples.
도 9를 참조하면, 실시예의 경우 음극 방전 프로파일이, 흑연계 코팅층에 의해 방전 반응 전위가 낮아졌음을 확인할 수 있고, 이를 통해 풀셀의 방전 전위를 높여서 전지의 에너지 밀도를 향상시킬 수 있음을 예측할 수 있다. 또한, 초기효율의 경우, 실시예는 85.8 %이고, 비교예는 78.7 %를 나타내고 있어, 실시예의 경우 흑연계 코팅층에 의해 향상되었음을 알 수 있다.Referring to FIG. 9, in the case of the embodiment, it can be seen that the cathode discharge profile has a lower discharge reaction potential by the graphite coating layer, thereby increasing the discharge potential of the full cell to improve the energy density of the battery. have. In addition, in the case of initial efficiency, the Example is 85.8% and the comparative example showed 78.7%, and it can be seen that the Example was improved by the graphite coating layer.
도 10은 실시예와 비교예에서 제조된 전지를 이용하여 충방전 사이클 수명특성을 나타낸 그래프이다.10 is a graph showing charge and discharge cycle life characteristics using the batteries prepared in Examples and Comparative Examples.
도 10을 참조하면, 비교예의 경우 16 사이클 후, 40 %정도로 용량이 감소한 반면에, 실시예의 경우 98 % 이상의 용량을 유지하고 있어, 비교예의 경우보다 사이클 수명특성이 현저히 우수함을 확인할 수 있다.Referring to FIG. 10, in the comparative example, after 16 cycles, the capacity was reduced to about 40%, while in the example, the capacity was maintained at 98% or more, which shows that the cycle life characteristics were significantly better than in the comparative example.
한편, 본 명세서와 도면에 개시된 본 발명의 실시예들은 이해를 돕기 위해 특정 예를 제시한 것에 지나지 않으며, 본 발명의 범위를 한정하고자 하는 것은 아니다. 여기에 개시된 실시예들 이외에도 본 발명의 기술적 사상에 바탕을 둔 다른 변형예들이 실시 가능하다는 것은 본 발명이 속하는 기술분야에서 통상의 지식을 가진 자에게 자명한 것이다.On the other hand, the embodiments of the present invention disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (33)

  1. 집전체;Current collector;
    상기 집전체의 적어도 일면 또는 외면 전체에 형성되는 전극 활물질층;An electrode active material layer formed on at least one surface or an entire outer surface of the current collector;
    상기 전극 활물질층의 상면에 형성되며, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층; 및A graphite coating layer formed on an upper surface of the electrode active material layer and including graphite, a conductive material, and a first polymer binder; And
    상기 흑연계 코팅층의 상면에 형성되며, 제2 고분자 바인더를 포함하는 다공성 코팅층;을 구비하는 이차전지용 전극.And a porous coating layer formed on an upper surface of the graphite coating layer and including a second polymer binder.
  2. 제1항에 있어서,The method of claim 1,
    상기 집전체는, 평면상의 집전체, 중공형의 집전체, 와이어형 집전체, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체인 것을 특징으로 하는 이차전지용 전극.The current collector may be a planar current collector, a hollow current collector, a wire current collector, a wound wire current collector, a wound sheet current collector, or a mesh current collector.
  3. 제1항에 있어서,The method of claim 1,
    상기 흑연, 상기 도전재 및 상기 제1 고분자 바인더의 중량비가, 50:10:40 내지 90:1:9인 것을 특징으로 하는 이차전지용 전극.The weight ratio of the graphite, the conductive material and the first polymer binder is 50:10:40 to 90: 1: 9, the secondary battery electrode.
  4. 제1항에 있어서,The method of claim 1,
    상기 흑연계 코팅층에 형성된 기공의 크기가, 0.1 ㎛ 내지 5 ㎛이고, 기공도가 10 내지 70 %인 것을 특징으로 하는 이차전지용 전극.The size of the pores formed in the graphite coating layer is 0.1 ㎛ to 5 ㎛, the porosity of the secondary battery electrode, characterized in that 10 to 70%.
  5. 제1항에 있어서,The method of claim 1,
    상기 도전재는, 카본 블랙, 아세틸렌 블랙, 케첸 블랙, 탄소 섬유, 탄소 나노튜브, 그래핀으로 이루어진 군으로부터 선택되는 어느 하나 또는 이들 중 2종 이상의 혼합물을 포함하는 것을 특징으로 하는 이차전지용 전극.The conductive material is any one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fiber, carbon nanotube, graphene, or a mixture of two or more thereof.
  6. 제1항에 있어서,The method of claim 1,
    상기 제1 고분자 바인더는, 폴리비닐리덴 풀루오라이드 (polyvinylidene fluoride, PVDF), 헥사풀루오로프로필렌 (hexafluoro propylene, HFP), 폴리비닐리덴 풀루오라이드-헥사풀루오로프로필렌 (polyvinylidene fluoride-co-hexafluoro propylene), 폴리비닐리덴 풀루오라이드-트리클로로에틸렌(polyvinylidene fluoride-co-trichloroethylene), 폴리부틸 아크릴레이트 (polybutyl acrylate), 폴리메틸 메타크릴레이트 (polymethyl methacrylate), 폴리아크릴로니트릴 (polyacrylonitrile), 폴리비닐피롤리돈 (polyvinylpyrrolidone), 폴리비닐아세테이트 (polyvinylacetate), 에틸렌 비닐 아세테이트 공중합체 (polyethylene-co-vinyl acetate), 폴리에틸렌 옥사이드 (polyethylene oxide), 폴리아릴레이트 (polyarylate), 셀룰로오스 아세테이트 (cellulose acetate), 셀룰로오스 아세테이트 부틸레이트 (cellulose acetate butyrate), 셀룰로오스 아세테이트 프로피오네이트 (cellulose acetate propionate), 시아노에틸풀루란 (cyanoethylpullulan), 시아노에틸폴리비닐알콜 (cyanoethylpolyvinylalcohol), 시아노에틸셀룰로오스 (cyanoethylcellulose), 시아노에틸수크로오스 (cyanoethylsucrose), 풀루란 (pullulan), 카르복실 메틸 셀룰로오스 (carboxyl methyl cellulose), 스티렌부타디엔 고무 (styrene-butadiene rubber), 아크릴로니트릴스티렌부타디엔 공중합체 (acrylonitrile-styrene-butadiene copolymer) 및 폴리이미드 (polyimide)로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물인 것을 특징으로 하는 이차전지용 전극.The first polymer binder may be polyvinylidene fluoride (PVDF), hexafluoropropylene (HFP), polyvinylidene fluoride-hexafuluropropylene (polyvinylidene fluoride-co- hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, Polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate , Cellulose acetate butyrate, cellulose acetate propy Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl Any one selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer, and polyimide A secondary battery electrode, characterized in that the mixture of species or more.
  7. 제1항에 있어서,The method of claim 1,
    상기 다공성 코팅층에 형성된 기공의 크기가, 0.01 ㎛ 내지 10 ㎛이고, 기공도가 5 내지 95 %인 것을 특징으로 하는 이차전지용 전극.The size of the pores formed in the porous coating layer, 0.01 ㎛ to 10 ㎛, the porosity of the electrode for secondary batteries, characterized in that 5 to 95%.
  8. 제1항에 있어서,The method of claim 1,
    상기 다공성 코팅층은, 무기물 입자를 더 포함하는 것을 특징으로 하는 이차전지용 전극.The porous coating layer, the secondary battery electrode, characterized in that it further comprises inorganic particles.
  9. 제8항에 있어서,The method of claim 8,
    상기 무기물 입자와 상기 제2 고분자 바인더의 중량비가, 10:90 내지 95:5인 것을 특징으로 하는 이차전지용 전극.A weight ratio of the inorganic particles and the second polymer binder is 10:90 to 95: 5, the secondary battery electrode.
  10. 제8항에 있어서,The method of claim 8,
    상기 무기물 입자는, 유전율 상수가 5 이상인 무기물 입자, 리튬 이온 전달 능력을 갖는 무기물 입자 또는 이들의 혼합물인 것을 특징으로 하는 이차전지용 전극.The inorganic particles are inorganic particles having a dielectric constant of 5 or more, inorganic particles having a lithium ion transfer ability, or a mixture thereof.
  11. 제10항에 있어서,The method of claim 10,
    상기 유전율 상수가 5 이상인 무기물 입자는, BaTiO3, Pb(Zrx, Ti1-x)O3(PZT, 여기서, 0<x<1임), Pb1-xLaxZr1-yTiyO3(PLZT, 여기서, 0 < x < 1, 0 < y < 1임), (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3(PMN-PT, 여기서, 0 < x < 1), 하프니아(HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, ZrO2, Y2O3, Al2O3, SiC, SiO2, AlOOH, Al(OH)3 및 TiO2로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물인 것을 특징으로 하는 이차전지용 전극.The inorganic particles having a dielectric constant of 5 or more include BaTiO 3 , Pb (Zr x , Ti 1-x ) O 3 (PZT, where 0 <x <1), and Pb 1-x La x Zr 1-y Ti y O 3 (PLZT, where 0 <x <1, 0 <y <1), (1-x) Pb (Mg 1/3 Nb 2/3 ) O 3 -xPbTiO 3 (PMN-PT, where 0 <x <1), hafnia (HfO 2 ), SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , SiC, SiO 2 , AlOOH, A secondary battery electrode, characterized in that any one selected from the group consisting of Al (OH) 3 and TiO 2 or a mixture of two or more thereof.
  12. 제10항에 있어서,The method of claim 10,
    상기 리튬 이온 전달 능력을 갖는 무기물 입자는, 리튬 포스페이트(Li3PO4), 리튬 티타늄 포스페이트(LixTiy(PO4)3, 0<x<2, 0<y<3), 리튬 알루미늄 티타늄 포스페이트(LixAlyTiz(PO4)3, 0<x<2, 0<y<1, 0<z<3), (LiAlTiP)xOy계열 글래스(0<x<4, 0<y<13), 리튬 란탄 티타네이트(LixLayTiO3, 0<x<2, 0<y<3), 리튬 게르마니움 티오포스페이트(LixGeyPzSw, 0<x<4, 0<y<1, 0<z<1, 0<w<5), 리튬 나이트라이드(LixNy, 0<x<4, 0<y<2), SiS2(LixSiySz, 0<x<3, 0<y<2, 0<z<4)계열 글래스 및 P2S5(LixPySz, 0<x<3, 0<y<3, 0<z<7)계열 글래스로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물인 것을 특징으로 하는 이차전지용 전극.The inorganic particles having a lithium ion transfer capability include lithium phosphate (Li 3 PO 4 ), lithium titanium phosphate (Li x Ti y (PO 4 ) 3 , 0 <x <2, 0 <y <3), and lithium aluminum titanium Phosphate (Li x Al y Ti z (PO 4 ) 3 , 0 <x <2, 0 <y <1, 0 <z <3), (LiAlTiP) x O y series glass (0 <x <4, 0 < y <13), lithium lanthanum titanate (Li x La y TiO 3, 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li x Ge y P z S w , 0 <x < 4, 0 <y <1, 0 <z <1, 0 <w <5), lithium nitride (Li x N y , 0 <x <4, 0 <y <2), SiS 2 (Li x Si y S z , 0 <x <3, 0 <y <2, 0 <z <4) series glass and P 2 S 5 (Li x P y S z , 0 <x <3, 0 <y <3, 0 < z <7) secondary battery electrode, characterized in that any one or a mixture of two or more selected from the group consisting of glass.
  13. 제8항에 있어서,The method of claim 8,
    상기 무기물 입자의 평균 입경이 10 nm 내지 5 ㎛인 것을 특징으로 하는 이차전지용 전극.Secondary battery electrode, characterized in that the average particle diameter of the inorganic particles is 10 nm to 5 ㎛.
  14. 제1항에 있어서,The method of claim 1,
    상기 제2 고분자 바인더는, 폴리비닐리덴 풀루오라이드 (polyvinylidene fluoride, PVDF), 헥사풀루오로프로필렌 (hexafluoro propylene, HFP), 폴리비닐리덴 풀루오라이드-헥사풀루오로프로필렌 (polyvinylidene fluoride-co-hexafluoro propylene), 폴리비닐리덴 풀루오라이드-트리클로로에틸렌(polyvinylidene fluoride-co-trichloroethylene), 폴리부틸 아크릴레이트 (polybutyl acrylate), 폴리메틸 메타크릴레이트 (polymethyl methacrylate), 폴리아크릴로니트릴 (polyacrylonitrile), 폴리비닐피롤리돈 (polyvinylpyrrolidone), 폴리비닐아세테이트 (polyvinylacetate), 에틸렌 비닐 아세테이트 공중합체 (polyethylene-co-vinyl acetate), 폴리에틸렌 옥사이드 (polyethylene oxide), 폴리아릴레이트 (polyarylate), 셀룰로오스 아세테이트 (cellulose acetate), 셀룰로오스 아세테이트 부틸레이트 (cellulose acetate butyrate), 셀룰로오스 아세테이트 프로피오네이트 (cellulose acetate propionate), 시아노에틸풀루란 (cyanoethylpullulan), 시아노에틸폴리비닐알콜 (cyanoethylpolyvinylalcohol), 시아노에틸셀룰로오스 (cyanoethylcellulose), 시아노에틸수크로오스 (cyanoethylsucrose), 풀루란 (pullulan), 카르복실 메틸 셀룰로오스 (carboxyl methyl cellulose), 스티렌부타디엔 고무 (styrene-butadiene rubber), 아크릴로니트릴스티렌부타디엔 공중합체 (acrylonitrile-styrene-butadiene copolymer) 및 폴리이미드 (polyimide)로 이루어진 군으로부터 선택된 어느 하나 또는 이들 중 2종 이상의 혼합물인 것을 특징으로 하는 이차전지용 전극.The second polymer binder may be polyvinylidene fluoride (PVDF), hexafluoro propylene (HFP), polyvinylidene fluoride-hexafluorofluoropropylene (polyvinylidene fluoride-co- hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, Polyvinylpyrrolidone, polyvinylacetate, ethylene vinyl co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate , Cellulose acetate butyrate, cellulose acetate propy Cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl Any one selected from the group consisting of carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer, and polyimide A secondary battery electrode, characterized in that the mixture of species or more.
  15. 제1항에 있어서,The method of claim 1,
    상기 이차전지용 전극은, 음극인 것을 특징으로 하는 이차전지용 전극.The secondary battery electrode is a secondary battery electrode, characterized in that the negative electrode.
  16. 제15항에 있어서,The method of claim 15,
    상기 전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx);로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것을 특징으로 하는 이차전지용 전극.The electrode active material layer may be Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni or Fe metals (Me); Alloys composed of the metals (Me); And an oxide (MeOx) of the metals (Me); any one active material particle selected from the group consisting of, or a mixture of two or more thereof.
  17. 양극, 음극, 상기 양극과 상기 음극의 사이에 개재되는 세퍼레이터, 및 비수전해액을 포함하는 이차전지에 있어서,In the secondary battery comprising a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte,
    상기 음극은, 제1항의 이차전지용 전극인 이차전지.The negative electrode is a secondary battery electrode of claim 1.
  18. 전해질을 포함하는 리튬이온 공급 코어부;A lithium ion supply core unit including an electrolyte;
    상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 내부전극;An internal current collector having an open structure formed around an outer surface of the lithium ion supply core part, an internal electrode active material layer formed on an outer surface of the internal current collector, and an outer surface of the internal electrode active material layer, and formed of graphite, a conductive material, and a first polymer An internal electrode having a graphite coating layer including a binder, and a porous coating layer formed on an outer surface of the graphite coating layer and including a second polymer binder;
    상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및A separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode; And
    상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.A cable type secondary battery having a horizontal cross section including an external electrode formed surrounding the outer surface of the separation layer and having an external current collector and an external electrode active material layer.
  19. 제18항에 있어서,The method of claim 18,
    상기 열린 구조의 내부집전체는, 권선된 와이어형 집전체, 권선된 시트형 집전체 또는 메쉬형 집전체인 것을 특징으로 하는 케이블형 이차전지.The internal current collector of the open structure, the cable-type secondary battery, characterized in that the wound wire-type current collector, the wound sheet current collector or the mesh current collector.
  20. 제18항에 있어서,The method of claim 18,
    상기 내부전극은 음극이며,The internal electrode is a cathode,
    상기 내부전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx);로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것을 특징으로 하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.The internal electrode active material layer may include Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni, or Fe; Alloys composed of the metals (Me); And an oxide material (MeOx) of the metals (Me); any one active material particle selected from the group consisting of, or a mixture of two or more thereof.
  21. 제18항에 있어서,The method of claim 18,
    상기 외부전극은, 상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층 및 상기 외부전극 활물질층의 외면을 둘러싸며 형성된 외부집전체를 구비하거나,The external electrode may include an external electrode active material layer formed surrounding the outer surface of the separation layer and an external current collector formed surrounding the outer surface of the external electrode active material layer,
    상기 분리층의 외면을 둘러싸며 형성된 외부집전체 및 상기 외부집전체의 외면을 둘러싸며 형성된 외부전극 활물질층을 구비하거나,An outer current collector formed to surround the outer surface of the separation layer and an outer electrode active material layer formed to surround the outer surface of the outer current collector;
    상기 분리층의 외면을 둘러싸며 형성된 외부집전체 및 상기 외부집전체의 외면을 둘러싸며 상기 분리층과 접촉하도록 형성된 외부전극 활물질층을 구비하거나, 또는An outer current collector formed to surround the outer surface of the separation layer and an outer electrode active material layer formed to contact the separation layer and surrounding the outer surface of the outer current collector, or
    상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층 및 상기 외부전극 활물질층 내에 피복되어 있고, 상기 분리층의 외면을 이격된 상태로 둘러싸며 형성된 외부집전체를 구비하는 것을 특징으로 하는 케이블형 이차전지.Cable type secondary, characterized in that it comprises an external electrode active material layer formed to surround the outer surface of the separation layer and the outer current collector is coated in the outer electrode active material layer, and formed surrounding the outer surface of the separation layer spaced apart. battery.
  22. 전해질을 포함하는 리튬이온 공급 코어부;A lithium ion supply core unit including an electrolyte;
    상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체 및 상기 내부집전체의 외면에 형성된 내부전극 활물질층을 구비하는 내부전극;An inner electrode including an inner current collector having an open structure formed around an outer surface of the lithium ion supply core and an inner electrode active material layer formed on an outer surface of the inner current collector;
    상기 내부전극의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및A separation layer which prevents a short circuit of the electrode formed surrounding the outer surface of the inner electrode; And
    상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.It is formed surrounding the outer surface of the separation layer, the outside having an external current collector, an external electrode active material layer, a graphite-based coating layer comprising graphite, a conductive material and a first polymer binder, and a porous coating layer comprising a second polymer binder Cable type secondary battery having a horizontal cross-section including an electrode; extending in the longitudinal direction.
  23. 제22항에 있어서,The method of claim 22,
    상기 외부전극은 음극이며,The external electrode is a cathode,
    상기 외부전극 활물질층은, Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni 또는 Fe인 금속류(Me); 상기 금속류(Me)로 구성된 합금류; 및 상기 금속류(Me)의 산화물(MeOx)로 이루어진 군으로부터 선택된 어느 하나의 활물질 입자 또는 이들 중 2종 이상의 혼합물을 포함하는 것을 특징으로 하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.The external electrode active material layer may be Si, Sn, Li, Al, Ag, Bi, In, Ge, Pb, Pt, Ti, Zn, Mg, Cd, Ce, Cu, Co, Ni or Fe (Me); Alloys composed of the metals (Me); And any one active material particles selected from the group consisting of oxides (MeOx) of the metals (Me), or mixtures of two or more thereof.
  24. 제22항에 있어서,The method of claim 22,
    상기 외부전극은, 상기 분리층의 외면을 둘러싸며 형성된 제2 고분자 바인더를 포함하는 다공성 코팅층, 상기 다공성 코팅층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 상기 흑연계 코팅층의 외면을 둘러싸며 형성된 외부전극 활물질층, 및 상기 외부전극 활물질층의 외면을 둘러싸며 형성된 외부집전체를 구비하거나,The external electrode may include a porous coating layer including a second polymer binder formed around the outer surface of the separation layer, and a graphite coating layer including an graphite, a conductive material, and a first polymer binder formed around the outer surface of the porous coating layer. An external electrode active material layer formed surrounding the outer surface of the graphite coating layer, and an external current collector formed surrounding the outer surface of the external electrode active material layer,
    상기 분리층의 외면을 둘러싸며 형성된 외부집전체, 상기 외부집전체의 외면을 둘러싸며 형성된 외부전극 활물질층, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하거나,An outer current collector formed to surround the outer surface of the separation layer, an outer electrode active material layer formed to surround the outer surface of the outer current collector, formed to surround the outer surface of the outer electrode active material layer, and a graphite, a conductive material and a first polymer binder Graphite coating layer comprising a, and formed surrounding the outer surface of the graphite coating layer, and having a porous coating layer comprising a second polymer binder,
    상기 분리층의 외면을 둘러싸며 형성된 외부집전체, 상기 외부집전체의 외면을 둘러싸며 상기 분리층과 접촉하도록 형성된 외부전극 활물질층, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하거나, 또는An outer current collector formed to surround the outer surface of the separation layer, an outer electrode active material layer formed to contact the separation layer and surrounding the outer surface of the outer current collector, formed to surround the outer surface of the outer electrode active material layer, graphite, conductive A graphite coating layer comprising ash and a first polymer binder, and a porous coating layer formed surrounding the outer surface of the graphite coating layer and including a second polymer binder, or
    상기 분리층의 외면을 둘러싸며 형성된 외부전극 활물질층, 상기 외부전극 활물질층 내에 피복되어 있고, 상기 분리층의 외면을 이격된 상태로 둘러싸며 형성된 외부집전체, 상기 외부전극 활물질층의 외면을 둘러싸며 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면을 둘러싸며 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 것을 특징으로 하는 케이블형 이차전지.An outer electrode active material layer formed surrounding the outer surface of the separation layer, the outer current collector covered with the outer electrode active material layer, and formed to surround the outer surface of the separation layer and surrounding the outer surface of the outer electrode active material layer And a graphite coating layer including graphite, a conductive material, and a first polymer binder, and a porous coating layer including an outer surface of the graphite coating layer and including a second polymer binder. Type secondary battery.
  25. 제18항 또는 제22항에 있어서,The method of claim 18 or 22,
    상기 분리층은, 전해질층 또는 세퍼레이터인 것을 특징으로 하는 케이블형 이차전지.The separating layer is a cable type secondary battery, characterized in that the electrolyte layer or a separator.
  26. 제25항에 있어서,The method of claim 25,
    상기 전해질층은, PEO, PVdF, PVdF-HFP, PMMA, PAN 또는 PVAC를 사용한 겔형 고분자 전해질; 또는The electrolyte layer is a gel polymer electrolyte using PEO, PVdF, PVdF-HFP, PMMA, PAN or PVAC; or
    PEO, PPO(polypropylene oxide), PEI(polyethylene imine), PES(polyethylene sulphide) 또는 PVAc(polyvinyl acetate)를 사용한 고체 전해질; 중에서 선택된 전해질을 포함하는 것을 특징으로 하는 케이블형 이차전지.Solid electrolyte using PEO, polypropylene oxide (PPO), polyethylene imine (PEI), polyethylene sulphide (PES) or polyvinyl acetate (PVAc); Cable type secondary battery comprising an electrolyte selected from.
  27. 제26항에 있어서,The method of claim 26,
    상기 전해질층은, 리튬염을 더 포함하는 것을 특징으로 하는 케이블형 이차전지.The electrolyte layer, the cable-type secondary battery further comprises a lithium salt.
  28. 제27항에 있어서,The method of claim 27,
    상기 리튬염은, LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, (CF3SO2)2NLi, 클로로보란리튬, 저급지방족카르본산리튬 및 테트라페닐붕산리튬 중에서 선택된 1종 또는 2종 이상인 것을 특징으로 하는 케이블형 이차전지.The lithium salt is 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, Cable type secondary battery, characterized in that one or more selected from CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, chloroborane lithium, lower aliphatic lithium carbonate and lithium tetraphenyl borate.
  29. 제25항에 있어서,The method of claim 25,
    상기 세퍼레이터는, 에틸렌 단독중합체, 프로필렌 단독중합체, 에틸렌-부텐 공중합체, 에틸렌-헥센 공중합체 및 에틸렌-메타크릴레이트 공중합체로 이루어진 군에서 선택된 폴리올레핀계 고분자로 제조한 다공성 고분자 기재; 폴리에스테르, 폴리아세탈, 폴리아미드, 폴리카보네이트, 폴리이미드, 폴리에테르에테르케톤, 폴리에테르설폰, 폴리페닐렌옥사이드, 폴리페닐렌설파이트 및 폴리에틸렌나프탈렌으로 이루어진 군에서 선택된 고분자로 제조한 다공성 고분자 기재; 또는 무기물 입자 및 바인더 고분자의 혼합물로 형성된 다공성 고분자 기재인 것을 특징으로 하는 케이블형 이차전지.The separator may include a porous polymer substrate 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; A porous polymer 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; Or a porous polymer substrate formed of a mixture of inorganic particles and a binder polymer.
  30. 전해질을 포함하는 2 이상의 리튬이온 공급 코어부;At least two lithium ion supply core portions comprising an electrolyte;
    각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극;An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer; At least two internal electrodes formed on the outer surface of the graphite coating layer including one polymer binder and formed on an outer surface of the graphite coating layer, and having a porous coating layer including a second polymer binder;
    상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And
    상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.A cable type secondary battery having a horizontal cross section including an external electrode formed surrounding the outer surface of the separation layer and having an external current collector and an external electrode active material layer.
  31. 전해질을 포함하는 2 이상의 리튬이온 공급 코어부;At least two lithium ion supply core portions comprising an electrolyte;
    각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면에 형성된 내부전극 활물질층, 상기 내부전극 활물질층의 외면에 형성되고, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 상기 흑연계 코팅층의 외면에 형성되고, 제2 고분자 바인더를 포함하는 다공성 코팅층 및 상기 다공성 코팅층의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 및An inner current collector having an open structure formed around an outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed on an outer surface of the inner current collector, and an outer surface of the inner electrode active material layer; A graphite-based coating layer comprising a polymer binder, a porous coating layer formed on the outer surface of the graphite-based coating layer, and a separation layer for preventing a short circuit of the electrode formed surrounding the outer surface of the porous coating layer; Two or more internal electrodes disposed in parallel to each other; And
    상기 내부전극들의 외면을 함께 둘러싸며 형성되고, 외부집전체 및 외부전극 활물질층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.A cable type secondary battery having a horizontal cross section including an outer electrode formed to surround the outer surfaces of the inner electrodes and having an outer current collector and an outer electrode active material layer.
  32. 전해질을 포함하는 2 이상의 리튬이온 공급 코어부;At least two lithium ion supply core portions comprising an electrolyte;
    각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체 및 상기 내부집전체의 외면을 둘러싸며 형성된 내부전극 활물질층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극;Two or more internal electrodes disposed in parallel with each other including an inner current collector having an open structure formed around an outer surface of each lithium ion supply core and an inner electrode active material layer formed surrounding the outer surface of the inner current collector;
    상기 내부전극들의 외면을 함께 둘러싸며 형성된 전극의 단락을 방지하는 분리층; 및A separation layer surrounding the outer surfaces of the inner electrodes together to prevent a short circuit of the formed electrodes; And
    상기 분리층의 외면을 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.It is formed surrounding the outer surface of the separation layer, the outside having an external current collector, an external electrode active material layer, a graphite-based coating layer comprising graphite, a conductive material and a first polymer binder, and a porous coating layer comprising a second polymer binder Cable type secondary battery having a horizontal cross-section including an electrode; extending in the longitudinal direction.
  33. 전해질을 포함하는 2 이상의 리튬이온 공급 코어부;At least two lithium ion supply core portions comprising an electrolyte;
    각각의 상기 리튬이온 공급 코어부의 외면을 둘러싸며 형성된 열린 구조의 내부집전체, 상기 내부집전체의 외면을 둘러싸며 형성된 내부전극 활물질층 및 상기 내부전극 활물질층의 외면을 둘러싸며 형성된 전극의 단락을 방지하는 분리층을 구비하는 서로 평행하게 배치되는 2 이상의 내부전극; 및An inner current collector having an open structure formed surrounding the outer surface of each of the lithium ion supply cores, an inner electrode active material layer formed surrounding the outer surface of the inner current collector, and a short circuit of the electrode formed surrounding the outer surface of the inner electrode active material layer Two or more internal electrodes disposed in parallel with each other having a separation layer for preventing; And
    상기 내부전극들의 외면을 함께 둘러싸며 형성되고, 외부집전체, 외부전극 활물질층, 흑연, 도전재 및 제1 고분자 바인더를 포함하는 흑연계 코팅층, 및 제2 고분자 바인더를 포함하는 다공성 코팅층을 구비하는 외부전극;을 포함하는 수평 단면을 가지고 길이 방향으로 연장된 케이블형 이차전지.It is formed to surround the outer surface of the internal electrodes together, having an external current collector, an external electrode active material layer, a graphite-based coating layer comprising a graphite, a conductive material and a first polymer binder, and a porous coating layer comprising a second polymer binder Cable type secondary battery extending in the longitudinal direction having a horizontal cross-section including an external electrode.
PCT/KR2013/011514 2012-12-12 2013-12-12 Electrode for secondary battery, secondary battery comprising same, and cable-type secondary battery WO2014092473A1 (en)

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JP2014552146A JP6316207B2 (en) 2012-12-12 2013-12-12 Secondary battery electrode, secondary battery including the same, and cable type secondary battery
CN201380006039.8A CN104067418B (en) 2012-12-12 2013-12-12 Electrode for secondary battery, the secondary cell that comprises it and cable Type Rechargeable Battery
US14/280,803 US9214672B2 (en) 2012-12-12 2014-05-19 Electrode for secondary battery, secondary battery and cable-type secondary battery comprising the same

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Citations (5)

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Publication number Priority date Publication date Assignee Title
KR20000045100A (en) * 1998-12-30 2000-07-15 고장면 Method for manufacturing a secondary lithium ion battery using a polymer electrolyte
US6488721B1 (en) * 2000-06-09 2002-12-03 Moltech Corporation Methods of preparing electrochemical cells
KR20090051546A (en) * 2007-11-19 2009-05-22 주식회사 엘지화학 A separator having porous coating layer and electrochemical device containing the same
KR20120000744A (en) * 2010-06-28 2012-01-04 주식회사 엘지화학 Anode for cable type secondary battery and cable type secondary battery having the same
US8119273B1 (en) * 2004-01-07 2012-02-21 The United States Of America As Represented By The Department Of Energy Unique battery with an active membrane separator having uniform physico-chemically functionalized ion channels and a method making the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20000045100A (en) * 1998-12-30 2000-07-15 고장면 Method for manufacturing a secondary lithium ion battery using a polymer electrolyte
US6488721B1 (en) * 2000-06-09 2002-12-03 Moltech Corporation Methods of preparing electrochemical cells
US8119273B1 (en) * 2004-01-07 2012-02-21 The United States Of America As Represented By The Department Of Energy Unique battery with an active membrane separator having uniform physico-chemically functionalized ion channels and a method making the same
KR20090051546A (en) * 2007-11-19 2009-05-22 주식회사 엘지화학 A separator having porous coating layer and electrochemical device containing the same
KR20120000744A (en) * 2010-06-28 2012-01-04 주식회사 엘지화학 Anode for cable type secondary battery and cable type secondary battery having the same

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