WO2014157987A1 - Ensemble électrode pour batterie rechargeable et batterie rechargeable utilisant celui-ci - Google Patents

Ensemble électrode pour batterie rechargeable et batterie rechargeable utilisant celui-ci Download PDF

Info

Publication number
WO2014157987A1
WO2014157987A1 PCT/KR2014/002664 KR2014002664W WO2014157987A1 WO 2014157987 A1 WO2014157987 A1 WO 2014157987A1 KR 2014002664 W KR2014002664 W KR 2014002664W WO 2014157987 A1 WO2014157987 A1 WO 2014157987A1
Authority
WO
WIPO (PCT)
Prior art keywords
active material
material layer
negative electrode
conductive metal
positive electrode
Prior art date
Application number
PCT/KR2014/002664
Other languages
English (en)
Korean (ko)
Inventor
최원길
노승윤
장주희
Original Assignee
주식회사 아모그린텍
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 아모그린텍 filed Critical 주식회사 아모그린텍
Priority claimed from KR1020140036627A external-priority patent/KR101592353B1/ko
Publication of WO2014157987A1 publication Critical patent/WO2014157987A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a secondary battery electrode assembly and a secondary battery using the same to form a porous conductive metal layer on the surface of the particles of the active material to improve the electrical conductivity and ion conductivity.
  • Lithium secondary batteries generate electrical energy by oxidation and reduction reactions when lithium ions are intercalated / deintercalated at a positive electrode and a negative electrode.
  • a lithium secondary battery is prepared by using a material capable of reversibly intercalating / deintercalating lithium ions as an active material of a positive electrode and a negative electrode, and filling an organic electrolyte or a polymer electrolyte between the positive electrode and the negative electrode.
  • a lithium secondary battery is composed of an electrode assembly in which a negative electrode plate and a positive electrode plate are wound or stacked in a predetermined form with a separator (separation membrane) interposed therebetween, and a case in which the electrode assembly and the electrolyte solution are stored.
  • the basic function of the separator of the lithium secondary battery is to prevent the short circuit by separating the positive electrode and the negative electrode, and furthermore, it is important to suck the electrolyte required for the battery reaction and maintain high ion conductivity.
  • an additional function is required to prevent the movement of substances that inhibit battery reaction or to secure safety when an abnormality occurs.
  • Lithium-ion secondary batteries with high energy density and large capacity, secondary batteries including lithium-ion polymer batteries should have a relatively high operating temperature range, and the temperature rises when they are continuously used in high rate charge / discharge states. Separators are required to have higher heat resistance and thermal stability than those required by ordinary separators. In addition, it should have excellent battery characteristics such as high ion conductivity that can cope with rapid charging and discharging and low temperature.
  • the separator is located between the anode and the cathode of the battery to insulate it, maintains the electrolyte to provide a path for ion conduction, and when the temperature of the battery becomes too high, a part of the separator melts to block pores in order to block the current.
  • the separator When the temperature rises further and the separator melts, a large hole is formed, which causes a short circuit between the anode and the cathode. This temperature is called SHORT CIRCUIT TEMPERATURE. In general, the separator should have a low shutdown temperature and a higher short circuit temperature.
  • the electrode part when an abnormal heat generation of the battery occurs, the electrode part may be contracted at 150 ° C. or more, resulting in a short circuit. Therefore, it is very important to have both the closing function and the heat resistance for high energy density and large sized secondary battery. That is, a separator having excellent heat resistance, low thermal shrinkage, and excellent cycle performance according to high ion conductivity is required.
  • polyolefin-based microporous polymer membranes such as polypropylene and polyethylene or multiple membranes thereof are usually used.
  • the porous membrane layer is in the form of a sheet or a film, there is a drawback that the sheet-like separator shrinks together with the pore blocking of the porous membrane due to heat generation due to internal short circuit or overcharge. Therefore, when the sheet-like separator collapses due to the internal heat generation of the battery, the separator is reduced and the missing part is directly in contact with the positive electrode and the negative electrode, which leads to ignition, rupture, and explosion.
  • LiCoO 2 is a material with excellent thermal stability and stable charge and discharge characteristics and high electron conductivity. Recently, however, there is a need for a cathode active material for a lithium secondary battery having a high voltage and a large capacity. When LiCoO 2 is continuously charged and discharged at 4.3 V or higher, the cathode active material reacts with the electrolyte due to lattice deformation or destruction of crystal structure. By doing so, life characteristics and safety are lowered. In addition, Co, which is the starting material of the positive electrode active material, has a tendency to continuously increase in price due to the small reserves, and further development of alternative positive electrode active material is needed due to the toxicity and environmental pollution problem to the human body.
  • LiNiO 2 , LiMn 2 O 4 , LiFePO 4 , and Li (NixCoyMnz) O 2 may be mentioned as positive electrode active materials for lithium secondary batteries that are actively researched and developed.
  • LiNiO 2 is not only difficult to synthesize, but also difficult to commercialize due to problems of thermal stability, while LiMn 2 O 4 has been commercialized in low-priced products, but due to Jahn-Teller distortion due to Mn3 + The property is not good.
  • LiFePO 4 has a low price and excellent safety and is currently being studied for HEV, but due to low conductivity it is difficult to apply to other fields.
  • Li (NixCoyMnz) O 2 is the most recently attracting attention as an alternative cathode active material for LiCoO 2 .
  • This material is cheaper than LiCoO 2 and has the advantage of being able to be used for high capacity and high voltage, but has disadvantages of poor rate characteristics and long life at high temperatures.
  • lithium in manufacturing a lithium secondary battery, lithium can be distributed evenly in the positive electrode active material and maximize the doping effect to improve the structural stability and electrochemical properties to prevent degradation of the battery performance as described above
  • cathode active materials for secondary batteries There is a need for research on cathode active materials for secondary batteries.
  • Korean Patent Application Publication No. 10-2010-56106 proposes a cathode active material for a lithium secondary battery having excellent structural stability and electrochemical properties by maximizing the doping effect of an additive element.
  • Electron conduction networks alone have limitations in ion conductivity.
  • An object of the present invention is to form a porous conductive metal layer on the particle surface of the electrode active material layer to form a metal network by the porous conductive metal layer in addition to the electron conductive network by the conductive material mixed with the active material inside the electrode to improve the ion conductivity accordingly It is to provide a secondary battery electrode assembly and a secondary battery using the same that can improve the performance of the battery.
  • Another object of the present invention is to improve the electrical conductivity of the electrode surface by adding a metal network in addition to the electron conductive network to increase the movement speed of the lithium ion, the electrode assembly for a secondary battery that can achieve high power and high capacity characteristics and It is to provide a secondary battery using the same.
  • the secondary battery electrode assembly of the present invention includes a negative electrode having a negative electrode current collector and a negative electrode active material layer formed on at least one surface of the negative electrode current collector; A positive electrode having a positive electrode current collector and a positive electrode active material layer formed on at least one surface of the positive electrode current collector; A porous separator formed between the cathode and the anode; And a porous conductive metal layer formed on at least one surface of the negative electrode active material layer and the positive electrode active material layer and having a plurality of pores to allow the movement of lithium ions.
  • Each of the negative electrode and the positive electrode includes an electron conductive network by a conductive agent mixed with an active material and a metal network by the porous conductive metal layer, respectively, and as a result, the electrical conductivity, the ion conductivity, and the capacity of the battery can be improved.
  • the conductive metal layer is deposited on the surface of the particles of the negative electrode active material layer or the positive electrode active material layer in the form of a plurality of point particles are interconnected to form a metal network, it is preferable that pores for moving lithium ions are formed between the particles and the particles.
  • the conductive metal layer formed on the cathode active material layer of the present invention may be formed of Al or Ni, and the conductive metal layer formed on the anode active material layer may be formed of Cu or Ni.
  • the conductive metal layer is preferably set to a thickness of 30 to 400 kPa, preferably formed by a vacuum deposition method.
  • the conductive metal layer formed on the negative electrode active material layer is set in the range of 30 ⁇ 300 ⁇
  • the conductive metal layer formed on the positive electrode active material layer is preferably set in the range of 110 ⁇ 400 ⁇ .
  • the electrode assembly according to the present invention is assembled in a case and filled with an electrolyte to constitute a secondary battery.
  • the electrolyte solution comprises an organic electrolyte containing a non-aqueous organic solvent, a solute of lithium salt, a monomer for forming a gel polymer, and a polymerization initiator, and the electrolyte solution is impregnated into the porous separator and then polymerizes the gel polymer forming monomer. As a result, a gel polymer electrolyte is formed, and the porous separator serves as an electrolyte matrix in the gel polymer electrolyte.
  • the electrolyte solution may be an organic electrolyte solution containing a solute of a non-aqueous organic solvent and a lithium salt.
  • the electrode assembly according to the present invention can be applied to a secondary battery such as a lithium ion battery or a lithium polymer battery.
  • the electrode assembly for secondary batteries of the present invention forms a porous conductive metal layer on the surface of the particles of the negative electrode active material layer and / or the positive electrode active material layer by a deposition method, and thus conducts electrons by the conductive agent mixed with the active material in the electrode.
  • a metal network may be formed by the porous conductive metal layer, thereby improving electrical conductivity, ion conductivity, and battery capacity.
  • FIG. 1 is a cross-sectional view illustrating an electrode assembly for a secondary battery according to a first embodiment of the present invention.
  • FIG. 2 is a cross-sectional view illustrating an electrode assembly for a secondary battery according to a second embodiment of the present invention.
  • FIG 3 is an enlarged view conceptually illustrating a state in which an electrically conductive metal layer is deposited on the surface of an active material layer of the present invention.
  • FIG. 4A is a SEM photograph taken at 2000 times magnification of a negative electrode sample of Comparative Example 1.
  • FIG. 4A is a SEM photograph taken at 2000 times magnification of a negative electrode sample of Comparative Example 1.
  • FIG. 4B to 4E are SEM images taken at 2000 times magnification of the negative electrode samples of Examples 2 to 5.
  • FIG. 4B to 4E are SEM images taken at 2000 times magnification of the negative electrode samples of Examples 2 to 5.
  • 5A is a SEM photograph taken at 2000 times magnification of the positive electrode sample of Comparative Example 2.
  • 5B to 5C are SEM images taken at 2000 times magnification of the positive electrode samples of Examples 8 to 10.
  • FIG. 1 is SEM images taken at 2000 times magnification of the positive electrode samples of Examples 8 to 10.
  • FIG. 1 is a cross-sectional view showing an electrode assembly according to a first embodiment of the present invention
  • Figure 2 is a cross-sectional view of an electrode assembly according to a second embodiment of the present invention.
  • the electrode assembly 10 for a secondary battery according to the present invention largely includes a negative electrode 1 and a positive electrode 2.
  • the negative electrode 1 is disposed to face the positive electrode 2 and includes a pair of negative electrode active material layers 13a and 13b formed on both sides of the negative electrode current collector 11 to form a bicell.
  • the negative electrode 1 may have a structure in which a negative electrode active material layer is provided on one surface of the negative electrode current collector 11.
  • the positive electrode 2 includes positive electrode active material layers 23a and 23b formed on both surfaces of the positive electrode current collector 21 to form a bicell.
  • the cathode 2 may have a structure in which a cathode active material layer is formed on one surface of the cathode current collector 21.
  • the cathode active material layers 23a and 23b include a cathode active material capable of reversibly intercalating and deintercalating lithium ions.
  • Representative examples of the cathode active material include LiCoO 2 , LiNiO 2 , LiNiCoO 2 , LiFeO 4 , and the like.
  • the positive electrode active material is largely divided into five types such as lithium cobalt-based (LCO), lithium nickel cobalt manganese (NCM), lithium nickel cobalt aluminum (NCA), lithium manganese (LMO) and lithium iron phosphate (LFP) Are distinguished.
  • LCO lithium cobalt-based
  • NCM lithium nickel cobalt manganese
  • NCA lithium nickel cobalt aluminum
  • LMO lithium manganese
  • LFP lithium iron phosphate
  • the negative electrode active material layers 13 and 13a include a negative electrode active material capable of intercalating and deintercalating lithium ions, and the negative electrode active material includes a carbon-based negative electrode of crystalline or amorphous carbon, carbon fiber, or carbon composite material. It can be selected from the group consisting of an active material, tin oxide, lithiated thereof, lithium, lithium alloys and mixtures thereof.
  • the negative electrode 1 and the positive electrode 2 are prepared by mixing an appropriate amount of an active material, a conductive agent, a binder, and an organic solvent to prepare a slurry, and then, as the negative electrode and the positive electrode current collectors 11 and 21, on both sides of a copper or aluminum sheet or the like.
  • the resulting slurry can be obtained by casting, drying and rolling.
  • Examples of the conductive agent include graphite, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, summer black, carbon fiber, metal fiber, carbon fluoride, aluminum, nickel powder, zinc oxide and potassium titanate. At least one selected from titanium oxide and polyphenylene derivatives may be used.
  • the positive electrode is used by casting a slurry composed of LiCoO 2 , super-P carbon, PVdF as an active material, a conductive agent, a binder on an aluminum foil, and the negative electrode is MCMB (mesocarbon microbeads), super-P carbon, PVdF
  • MCMB mesocarbon microbeads
  • the constructed slurry can be cast and used in aluminum foil.
  • the porous separators 3a and 3b formed in the multilayer structure on the surface of the negative electrode 1 each include a first polymer made of a polymer that swells in the electrolyte so as to cover the negative electrode active material layers 13a and 13b and is capable of conducting electrolyte ions.
  • the inorganic-porous polymer film layers 31a and 31b, and the inorganic-containing porous polymer web layers 33a and 33b made of ultrafine fibrous forms of a mixture of heat resistant polymer or heat resistant polymer and swellable polymer and inorganic particles.
  • separators 3a and 3b may be separately formed without directly forming the cathode 1, and then inserted and encapsulated between the cathode and the anode when assembling the anode and the cathode.
  • a metal network is formed in addition to the electron conductive network by carbon black or other conductive agent contained in the negative electrode active material layer and the positive electrode active material layer.
  • Porous conductive metal layers 50 and 60 may be formed to improve performance.
  • the porous conductive metal layers 50 and 60 are formed of the porous first conductive metal layer 50 formed on the surface of the negative electrode active material layer 13a and the porous second conductive metal layer 60 formed on the surface of the positive electrode active material layer 23a. Include.
  • the thicknesses of the first and second conductive metal layers 50 and 60 are preferably set to 30 to 400 kPa, respectively. More preferably, the first conductive metal layer 50 is set in the range of 30 to 300 kPa, and the second conductive metal layer 60 is set in the range of 110 to 400 kPa.
  • the thicknesses of the first and second conductive metal layers 50 and 60 are respectively less than 30 ⁇ s, the resistance increases, and the improvement of the electrical conductivity is insignificant. Rather, it adversely affects battery characteristics.
  • the first conductive metal layer 50 formed on the surface of the negative electrode active material layer 13a increases in resistance as the thickness increases or decreases, and the second conductive metal layer 60 formed on the surface of the positive electrode active material layer 23a As the thickness increases or decreases, the resistance value and the electrical conductivity tend to increase.
  • the first conductive metal layer 50 may be formed of Cu or Ni
  • the second conductive metal layer 60 may be formed of Al or Ni.
  • a plurality of pores 70 are formed in the porous conductive metal layers 50 and 60 to allow lithium ions to pass therethrough. That is, when the conductive metal layers 50 and 60 completely cover the particle surfaces of the active material layers 13a and 23a, the movement of lithium ions is suppressed and the performance is reduced, thereby securing pores 70 through which lithium ions can be sufficiently transferred. It is formed in one form.
  • the conductive metal layers 50 and 60 are formed by a deposition method, for example, thermal evaporation or electron-beam evaporation, and the like.
  • the deposition conditions are appropriately adjusted so that the conductive metal layers 50 and 60 are deposited in the form of point particles 80 so as to be partially interconnected, thereby depositing the particles 80 and 80. While forming a metal network of a three-dimensional structure between the) to partially secure the pores (70) to allow sufficient lithium ions to pass through.
  • a method for forming the conductive metal layer a method such as sputtering, chemical vapor deposition (CVD), and physical vapor deposition (PVD) may be applied in addition to the thermal evaporation described above.
  • CVD chemical vapor deposition
  • PVD physical vapor deposition
  • the conductive metal layers 50 and 60 on the surface of the particles of the negative electrode active material layer and the positive electrode active material layer, a three-dimensional metal network having pores 70 which are passages through which lithium ions pass is formed.
  • the electrical conductivity and the ion conductivity can be improved, thereby improving the performance of the electrode.
  • the ion conductivity is low, and the conductive metal layer is formed on the surface of the particles of the negative electrode active material layer and the positive electrode active material layer of the present embodiment in the form of dot particles to form a metal between the deposited particles 80 and the particles 80.
  • the pores 70 may be partially secured to improve electrical conductivity and ion conductivity, thereby improving battery performance.
  • a porous conductive metal layer is formed on the surface of the negative electrode active material layer and the positive electrode active material layer of the present embodiment to improve the electrical conductivity and the ion conductivity, thereby improving the performance of the battery.
  • a porous polymer web obtained by electrospinning the swellable polymer instead of the first inorganic porous polymer film layers 31a and 31b may be used.
  • the porous polymer web may be formed by dissolving a swellable polymer in a solvent to form a spinning solution, and then electrospinning the spinning solution on a negative electrode active material layer to form a porous polymer web made of ultra-fine fibers.
  • PVDF is obtained by calendering the porous polymer web at a temperature lower than the melting point of PVDF).
  • the first inorganic porous polymer film layers 31a and 31b formed to cover the negative electrode active material layers 13a and 13b in the negative electrode 1 are swelled in the electrolyte and are capable of conducting electrolyte ions, for example, PVDF. (Polyvinylidene fluoride), PEO (Poly-Ethylen Oxide), PMMA (polymethyl methacrylate), TPU (Thermoplastic Poly Urethane) can be used.
  • the first inorganic porous polymer film layers 31a and 31b form a spinning solution by dissolving the polymer in a solvent, and then electrospinning the spinning solution on the anode active material layer to form a porous polymer web made of ultra-fine fibrous fibers. By heat-treating or calendering the porous polymer web at a temperature lower than the melting point of the polymer, the polymer film layers 31a and 31b of the inorganic pores are obtained.
  • the heat treatment temperature may be performed at a temperature slightly lower than the melting point of the polymer because the solvent remains in the polymer web, and also to form the inorganic porous film while preventing the polymer web from completely melting by the heat treatment. to be.
  • the inorganic porous polymer film layers 31a and 31b made of a material capable of conducting electrolyte ions swelling in the electrolyte solution are directly electrospun onto the surfaces of the negative electrode active material layers 13a and 13b.
  • swelling is performed by the electrolyte solution while maintaining conduction of lithium ions while blocking the formation of spaces between the negative electrode active material layers 13a and 13b and the film to prevent lithium ions from accumulating and depositing into lithium metal. can do.
  • dendrite formation can be suppressed on the surface of the cathode 1 and safety can be improved.
  • the inorganic-containing porous polymer web layers 33a and 33b formed on the first inorganic porous film layers 31a and 31b are formed by dissolving a mixture of a heat resistant polymer or a heat resistant polymer and a swellable polymer and an inorganic particle in a solvent to form a spinning solution. Thereafter, the spinning solution is electrospun on the first non-porous polymer film layers 31a and 31b to form a porous polymer web made of ultra-fine fibrous, and the obtained porous polymer web is formed by calendering at a temperature below the melting point of the polymer.
  • the inorganic particles are Al 2 O 3 , TiO 2 , BaTiO 3 , Li 2 O, LiF, LiOH, Li 3 N, BaO, Na 2 O, Li 2 CO 3 , CaCO 3 , LiAlO 2 , SiO 2 , SiO, SnO, SnO 2 , PbO 2 , ZnO, P 2 O 5 , CuO, MoO, V 2 O 5 , B 2 O 3 , Si 3 N 4 , CeO 2 , Mn 3 O 4 , Sn 2 P 2 O 7 , Sn 2 B At least one selected from 2 O 5 , Sn 2 BPO 6, and mixtures thereof can be used.
  • the content of the inorganic particles is preferably contained in the range of 10 to 25% by weight based on the total mixture when the size of the inorganic particles is between 10 and 100 nm. More preferably, the inorganic particles are contained in the range of 10 to 20% by weight, and the size is in the range of 15 to 25 nm.
  • the heat resistant polymer and the swellable polymer are preferably mixed in a weight ratio of 5: 5 to 7: 3, and more preferably 6: 4.
  • the swellable polymer is added as a binder to help bond between the fibers.
  • the mixing ratio of the heat resistant polymer and the swellable polymer is less than 5: 5 by weight, the heat resistance is poor and does not have the required high temperature characteristics.
  • the mixing ratio is larger than 7: 3 by weight, the strength drops and the radiation trouble occurs.
  • the heat resistant polymer resin usable in the present invention is a resin that can be dissolved in an organic solvent for electrospinning and has a melting point of 180 ° C. or higher, for example, polyacrylonitrile (PAN), polyamide, polyimide, polyamideimide, Aromatic polyesters such as poly (meth-phenylene isophthalamide), polysulfones, polyetherketones, polyethylene terephthalates, polytrimethylene terephthalates, polyethylene naphthalates, and the like, polytetrafluoroethylene, polydiphenoxyphosphazenes Polyphosphazenes, such as poly ⁇ bis [2- (2-methoxyethoxy) phosphazene] ⁇ , polyurethane copolymers including polyurethanes and polyetherurethanes, cellulose acetates, cellulose acetate butyrates, cellulose acetate pros Cypionate and the like can be used.
  • PAN polyacrylonitrile
  • Polyamide polyimi
  • the swellable polymer resin usable in the present invention is a resin that swells in an electrolyte and can be formed into ultrafine fibers by electrospinning.
  • PVDF polyvinylidene fluoride
  • poly (vinylidene fluoride-co-hexa) Fluoropropylene) perfuluropolymer
  • poly (oxymethylene-oligo- Oxyethylene) polyoxides including polyethylene oxide and polypropylene oxide
  • polyvinylacetate poly (vinylpyrrolidone-vinylacetate)
  • polystyrene and polystyrene acrylonitrile copolymers polyacrylonitrile methyl methacrylate copolymers
  • Polyacrylic containing Casting reel can be given to the copolymer, polymethyl me
  • the separators 3a and 3b having a multi-layer structure are formed on the surface of the cathode 1.
  • the separators 3a and 3b may be formed on the surface of the anode 2 instead of the cathode 1.
  • the inorganic-containing porous polymer web layers 33: 33a and 33b are first formed on the surface of the anode 2, and the first inorganic porous polymer film layers 31: 31a and 31b are formed of the porous polymer web layer 33. It is formed on the surfaces of 33a and 33b to be in close contact with the cathode 1 during assembly.
  • the two-layer structure separation membranes 3a and 3b are formed on either the negative electrode 1 or the positive electrode 2, but the separation membrane 3 is the first as shown in the second embodiment shown in FIG. It is composed of the inorganic porous polymer film layers 31: 31a and 31b and the inorganic-containing porous polymer web layers 33: 33a and 33b, and may be formed separately from the cathode 1 and the anode 2.
  • the first non-porous polymer film layers 31: 31a and 31b are formed on the negative electrode 1 to cover the negative electrode active material layers 13a and 13b, and the inorganic material to cover the positive electrode active material layers 23a and 23b. It is also possible that the porous polymeric web layers 33: 33a and 33b are formed on the anode 2.
  • the second inorganic porous polymer film layer on the surfaces of the inorganic material-containing porous polymeric web layers 33a and 33b of the anode 2 in the same manner as the first inorganic porous polymer film layers 31a and 31b.
  • the first inorganic porous polymer film layers 31a and 31b and the second inorganic porous polymer film layer are bonded to each other.
  • the thickness of the inorganic-containing porous polymer web layers 33a and 33b is set in a range of 5 to 50um, and the thickness of the first inorganic porous polymer film layers 31a and 31b is set in a range of 5 to 14um.
  • the function of the separator is that the inorganic-containing porous polymer web layers 33a and 33b have a higher porosity than the first inorganic-porous polymer film layers 31a and 31b, so that the first inorganic rather than the inorganic-containing porous polymer web layers 33a and 33b.
  • the thickness of the first inorganic porous polymer film layers 31a and 31b is less than 5 ⁇ m, a micro short circuit occurs.
  • the thickness of the first inorganic porous polymer film layers 31a and 31b is greater than 14 ⁇ m, it is too thick to prevent the movement of Li ions, thereby preventing charge and discharge.
  • the thickness of the first inorganic porous polymer film layers 31a and 31b is preferably adjusted in consideration of the ion conductivity and energy density of the film layer.
  • the first inorganic porous polymer film layers 31a and 31b and the inorganic porous polymer web layers 33a and 33b serving as separators may be formed of the cathode 1 or the anode 2 as shown in FIG. 1. It encloses with a sealing structure, or surrounds the cathode 1 and the anode 2 simultaneously with the sealing structure like FIG.
  • the electrode assemblies 10 and 10a of the present invention may form a unit cell by simply stacking the cathode 1 and the anode 2, for example, a large capacity for an electric vehicle.
  • the present invention has a high assembly productivity compared to the prior art that goes through the process of folding a plurality of bi-cell with a separate membrane film.
  • the negative electrode 1 and the positive electrode 2 are provided with a negative electrode and a positive electrode terminal formed to protrude portions of the negative electrode and the positive electrode current collectors 11 and 21.
  • the electrode assemblies 10 and 10a of the present invention are laminated and assembled with a plurality of negative electrodes 1 and positive electrodes 2, the negative electrode terminal 11a of the negative electrode 1 and the positive electrode terminal 21a of the positive electrode 2 as shown in FIG. 3. ) Are stacked so that they face in opposite directions.
  • porous polymer web layers 33a and 33b contain an inorganic material and thus retain their shape without shrinking or melting even when heat-treated at 500 ° C.
  • the electrode of the present invention maintains a constant voltage between 5V and 6V and a battery temperature of less than 100 ° C by continuously consuming overcharge current by causing a very small short-circuit rather than a hard short during overcharge. Overcharge stability can also be improved.
  • the electrode assembly according to the present invention may constitute a lithium ion battery or a lithium polymer battery as a secondary battery.
  • the electrode assembly according to the present invention constitutes a lithium ion battery (LIB), as shown in FIGS. 1 and 2, separators 3a, 3b; 3 are formed on the negative electrode 1 and the positive electrode 2, and the assembly is compressed.
  • One electrode assembly 10, 10a contains an electrolyte solution.
  • the electrolyte solution includes an organic electrolyte solution containing a non-aqueous organic solvent and a solute of a lithium salt, and the lithium salt serves as a source of lithium ions in the battery to enable operation of a basic lithium battery.
  • the electrode assembly according to the present invention constitutes a lithium polymer battery (LPB)
  • the lithium polymer battery includes a negative electrode (1), a positive electrode (2) and a polymer electrolyte inserted between the negative electrode and the positive electrode, the polymer electrolyte It consists of a porous membrane and a gel polymer that serves as an electrolyte matrix.
  • the lithium polymer battery is formed by integrally forming a porous separator on one of the negative electrode 1 and the positive electrode 2, preferably on the surface of the negative electrode 1, or by inserting it between the negative electrode 1 and the positive electrode 2 and pressing-assembled. Including an electrolyte in the electrode assembly.
  • the porous membrane may serve as an electrolyte matrix, and a composite porous membrane in which a single layer porous polymer web made of nanofibers, a porous polymer web or an inorganic porous polymer film, and a porous nonwoven fabric are stacked.
  • the electrolyte solution includes a non-aqueous organic solvent and a solute of a lithium salt, a monomer for forming a gel polymer, and a polymerization initiator.
  • the electrolyte When the electrolyte is charged while the electrode assembly is assembled to the case, the electrolyte is impregnated into the porous separator. After the gelation heat treatment, the gel polymer in the gel state is synthesized by the polymerization reaction of the monomer for forming the gel polymer. An electrolyte is formed.
  • the porous separator serves to separate the negative electrode 1 and the positive electrode 2 while serving as an electrolyte matrix in the gel polymer electrolyte.
  • the negative electrode is a mixture of graphite, conductive material (CB) and binder (PVdF) of 9g, 0.5g and 0.5g, respectively, dissolved in NMP (N-Methyl pyrrolidone), which is used as a solvent, and then cast into a copper foil.
  • NMP N-Methyl pyrrolidone
  • the negative electrode sample of Comparative Example 1 was prepared in 2Ah size without metal deposition, and a SEM photograph taken at 2000 times magnification of the negative electrode sample of Comparative Example 1 is shown in FIG. 4A.
  • a negative electrode of Comparative Example 1 was prepared in a size of 2 Ah, a negative electrode sample of 2 Ah size was mounted on a ceramic substrate jig of a thermal evaporator, and a jig was mounted on a rotary holder of the thermal evaporator. Cu metal was weighed in proportion to the thickness to be deposited and set in a tungsten boat.
  • Cu metal was deposited on the negative electrode sample by setting the thermal evaporator to 3.5 V, 120 A, and 3 min to deposit copper (Cu) at a thickness of 30 mV, 105 mV, 120 mV, 135 mV, 150 mV, and 300 mV for the negative electrode sample, respectively. Samples of 1 to 6 were prepared.
  • Example 2 half-cell tests for Example 2 and Example 5 were conducted to obtain battery capacity at the time of discharge, and are shown in Table 2 below.
  • Example 1 Sample Thickness Resistance value (m ⁇ cm) Electrical Conductivity (S / cm) Comparative Example 1 0 12.64 7.91 ⁇ 10 Example 1 30 8.001 1.04 ⁇ 10 2 Example 2 105 2.607 3.83 ⁇ 10 2 Example 3 120 2.648 3.77 ⁇ 10 2 Example 4 135 5.961 1.67 ⁇ 10 2 Example 5 150 6.460 1.54 ⁇ 10 2 Example 6 300 10.12 1.00 ⁇ 10 2
  • the samples of Examples 1 to 6 in which copper is deposited on the surface of the cathode according to the present invention have a resistance value and an electric conductivity characteristic compared to Comparative Example 1 in which copper is not deposited. It was found to be excellent, and the thinner the thickness of the deposited copper, the better the properties were. However, when the thickness of the deposited copper was too thin as in Example 1 or thickened as in Example 6, the resistance value increased and the electrical conductivity decreased.
  • Example 2 in which the thickness of copper was formed to 105 kW, showed the best resistance value, electrical conductivity, and capacity.
  • the positive electrode was mixed with 8 g, 1.5 g, and 0.5 g of a hybrid type active material, a conductive material (CB), and a binder (CMC, SBR), respectively, in which lithium nickel cobalt manganese (NCM) oxide and lithium manganese (LMO) oxide were mixed.
  • NCM nickel cobalt manganese
  • LMO lithium manganese
  • a positive electrode sample of Comparative Example 2 was prepared in 2Ah size without metal deposition, and a SEM photograph taken at 2000 times magnification of the positive electrode sample of Comparative Example 2 is shown in FIG. 5A.
  • a positive electrode of Comparative Example 2 was prepared in a size of 2 Ah, a positive electrode sample having a size of 2 Ah was mounted on a ceramic substrate jig of a thermal evaporator, and a jig was mounted on a rotary holder of the thermal evaporator. Al metal was weighed in proportion to the thickness to be deposited and set in a tungsten boat.
  • FIGS. 5B to 5D SEM pictures taken at 2000 times magnification of the samples of the obtained Examples 8 to 10 are shown in FIGS. 5B to 5D.
  • Example 8 the resistance value, the electrical conductivity, the ion conductivity, and the capacity were all superior to those of Comparative Example 2.
  • Example 7 when the thickness of the deposited aluminum was too thin as in Example 7, or thickened as in Example 11, the resistance value increased and the electrical conductivity decreased, and the ion conductivity and the capacity of the battery also decreased. If the thickness is too thin or too thick, the properties were found to be inferior.
  • the electrode assembly for secondary batteries of the present invention forms a porous conductive metal layer on the surface of the particles of the negative electrode active material layer and / or the positive electrode active material layer by a deposition method, and thus conducts electrons by the conductive agent mixed with the active material in the electrode.
  • a metal network may be formed by the porous conductive metal layer, thereby improving electrical conductivity, ion conductivity, and battery capacity.
  • a porous conductive metal layer having a plurality of pores of three-dimensional structure is formed on the surface of the negative electrode active material layer and the positive electrode active material layer of the present embodiment to improve electrical conductivity and ion conductivity. By improving, the performance of the battery can be improved.
  • the present invention partially forms a conductive metal layer on the particle surface of the electrode active material layer to form a metal network by the porous conductive metal layer in addition to the electronic conductive network by the conductive agent mixed with the active material in the electrode, thereby forming the electrical conductivity, ion conductivity and As a technique capable of improving the capacity, it can be applied to a secondary battery such as a lithium ion battery or a lithium polymer battery.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

La présente invention concerne un ensemble électrode pour une batterie rechargeable et une batterie rechargeable utilisant celui-ci. Selon l'invention, une couche métallique conductrice poreuse est formée sur des surfaces de particules d'une couche de matière active d'anode et/ou d'une couche de matière active de cathode au moyen d'un procédé de dépôt, ce qui permet ainsi de former un réseau métallique constitué d'une couche métallique conductrice poreuse ainsi qu'un réseau de conductibilité par électrons constitué d'un agent conducteur mélangé avec une matière active à l'intérieur de l'électrode, de sorte que l'ensemble électrode peut améliorer la conductivité électrique, la conductivité des ions et la capacité de la batterie. L'ensemble électrode pour la batterie rechargeable selon la présente invention comprend : une anode ayant un collecteur de courant d'anode et une couche de matière active d'anode formée sur au moins une surface du collecteur de courant d'anode ; une cathode ayant un collecteur de courant de cathode et une couche de matière active de cathode formée sur au moins une surface du collecteur de courant de cathode ; un film de séparation poreux formé entre la cathode et l'anode ; et une couche métallique conductrice poreuse formée sur au moins une surface de la couche de matière active de cathode et de la couche de matière active d'anode, la couche métallique conductrice poreuse ayant une pluralité de pores pour permettre le mouvement des ions lithium.
PCT/KR2014/002664 2013-03-28 2014-03-28 Ensemble électrode pour batterie rechargeable et batterie rechargeable utilisant celui-ci WO2014157987A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR20130033651 2013-03-28
KR10-2013-0033651 2013-03-28
KR10-2014-0036627 2014-03-28
KR1020140036627A KR101592353B1 (ko) 2013-03-28 2014-03-28 이차전지용 전극 조립체 및 이를 이용한 이차전지

Publications (1)

Publication Number Publication Date
WO2014157987A1 true WO2014157987A1 (fr) 2014-10-02

Family

ID=51624841

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2014/002664 WO2014157987A1 (fr) 2013-03-28 2014-03-28 Ensemble électrode pour batterie rechargeable et batterie rechargeable utilisant celui-ci

Country Status (1)

Country Link
WO (1) WO2014157987A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107978762A (zh) * 2016-10-21 2018-05-01 罗伯特·博世有限公司 具有在活性材料结构上的导电网格的电极
WO2024073897A1 (fr) * 2022-10-08 2024-04-11 宁德时代新能源科技股份有限公司 Feuille d'électrode négative, batterie secondaire et appareil électrique

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010082917A (ko) * 2000-02-22 2001-08-31 박호군 다공성 금속박막이 피복된 탄소전극 및 그 제조방법, 이를이용한 리튬 이차전지
KR20090076275A (ko) * 2008-01-08 2009-07-13 주식회사 엘지화학 음극, 이의 제조방법, 및 이를 포함하는 리튬 이차 전지
KR100953543B1 (ko) * 2003-12-01 2010-04-21 삼성에스디아이 주식회사 리튬 애노드, 그의 제조방법 및 이를 채용한 리튬 전지
KR20100097767A (ko) * 2002-08-24 2010-09-03 에보닉 데구사 게엠베하 리튬 이온 배터리용 분리막-전극 유닛, 이의 제조방법 및 이를 포함하는 리튬 배터리
KR20130011670A (ko) * 2011-07-22 2013-01-30 주식회사 엘지화학 전기적 안전성이 향상된 리튬 이차전지

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010082917A (ko) * 2000-02-22 2001-08-31 박호군 다공성 금속박막이 피복된 탄소전극 및 그 제조방법, 이를이용한 리튬 이차전지
KR20100097767A (ko) * 2002-08-24 2010-09-03 에보닉 데구사 게엠베하 리튬 이온 배터리용 분리막-전극 유닛, 이의 제조방법 및 이를 포함하는 리튬 배터리
KR100953543B1 (ko) * 2003-12-01 2010-04-21 삼성에스디아이 주식회사 리튬 애노드, 그의 제조방법 및 이를 채용한 리튬 전지
KR20090076275A (ko) * 2008-01-08 2009-07-13 주식회사 엘지화학 음극, 이의 제조방법, 및 이를 포함하는 리튬 이차 전지
KR20130011670A (ko) * 2011-07-22 2013-01-30 주식회사 엘지화학 전기적 안전성이 향상된 리튬 이차전지

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107978762A (zh) * 2016-10-21 2018-05-01 罗伯特·博世有限公司 具有在活性材料结构上的导电网格的电极
WO2024073897A1 (fr) * 2022-10-08 2024-04-11 宁德时代新能源科技股份有限公司 Feuille d'électrode négative, batterie secondaire et appareil électrique

Similar Documents

Publication Publication Date Title
US11018379B2 (en) Electrode, secondary battery using same, and method for manufacturing electrode
KR102119801B1 (ko) 플렉시블 집전체 및 이를 이용한 이차전지
KR101246827B1 (ko) 전극 조립체 및 이를 이용한 이차 전지와 그의 제조방법
KR102486801B1 (ko) 이차전지
WO2012165758A1 (fr) Batterie secondaire au lithium
CN111954943A (zh) 隔板、用于制造其的方法和包括其的锂电池
WO2015020338A1 (fr) Collecteur de courant souple et son procédé de fabrication, et batterie secondaire utilisant ledit collecteur
WO2017188537A1 (fr) Séparateur comprenant une couche adhésive poreuse et batterie rechargeable au lithium utilisant celui-ci
WO2018212481A1 (fr) Procédé de fabrication d'anode destinée à une batterie secondaire au lithium
WO2015002390A1 (fr) Mélange cathodique à conductivité améliorée, et cathode et dispositif électrochimique contenant ce mélange
WO2017111566A1 (fr) Matériau actif d'électrode négative présentant des caractéristiques de rendement améliorées, et électrode pour dispositif électrochimique contenant le matériau actif d'électrode négative
WO2021080052A1 (fr) Structure d'anode métallique au lithium, dispositif électrochimique la comprenant, et procédé de fabrication de structure d'électrode métallique au lithium
WO2019093836A1 (fr) Électrode en forme de bande destinée à un rouleau de gelée cylindrique et pile rechargeable au lithium comprenant une telle électrode
KR101705307B1 (ko) 상 전환법을 이용한 전기화학소자용 세퍼레이터의 제조방법, 그로부터 형성된 세퍼레이터 및 그를 포함하는 전기화학소자
KR101592353B1 (ko) 이차전지용 전극 조립체 및 이를 이용한 이차전지
WO2019221410A1 (fr) Électrode négative comprenant une couche de protection d'électrode et batterie secondaire au lithium l'utilisant
WO2016117950A1 (fr) Batterie secondaire au lithium présentant de meilleures caractéristiques de sortie
WO2019045552A1 (fr) Procédé de fabrication de batterie flexible, et batterie flexible ainsi fabriquée
US20150132626A1 (en) Electrode assembly and secondary battery using the electrode assembly
WO2021133127A1 (fr) Suspension aqueuse d'électrode positive, composition d'électrode positive, batterie secondaire au lithium-ion comprenant ladite composition d'électrode positive, et leurs procédés de fabrication
KR20170135593A (ko) 복합음극활물질, 이를 포함하는 음극 및 리튬전지, 및 이의 제조 방법
WO2018135929A1 (fr) Électrode négative pour batterie secondaire au lithium, batterie secondaire au lithium la comprenant et son procédé de fabrication
WO2020050559A1 (fr) Séparateur pour accumulateur n'ayant pas de substrat de séparateur
WO2014157987A1 (fr) Ensemble électrode pour batterie rechargeable et batterie rechargeable utilisant celui-ci
WO2017082680A1 (fr) Matériau actif d'anode et accumulateur au lithium le comprenant

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14772582

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14772582

Country of ref document: EP

Kind code of ref document: A1