WO2023115264A1 - 导电胶、电化学装置和电子装置 - Google Patents

导电胶、电化学装置和电子装置 Download PDF

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WO2023115264A1
WO2023115264A1 PCT/CN2021/139726 CN2021139726W WO2023115264A1 WO 2023115264 A1 WO2023115264 A1 WO 2023115264A1 CN 2021139726 W CN2021139726 W CN 2021139726W WO 2023115264 A1 WO2023115264 A1 WO 2023115264A1
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conductive adhesive
conductive
present application
epoxy resin
matrix
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PCT/CN2021/139726
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English (en)
French (fr)
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胡克文
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东莞新能源科技有限公司
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Priority to PCT/CN2021/139726 priority Critical patent/WO2023115264A1/zh
Publication of WO2023115264A1 publication Critical patent/WO2023115264A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J179/00—Adhesives based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen, with or without oxygen, or carbon only, not provided for in groups C09J161/00 - C09J177/00
    • C09J179/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
    • C09J179/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • 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
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/534—Electrode connections inside a battery casing characterised by the material of the leads or tabs
    • 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 application relates to the field of energy storage, in particular to a conductive glue, an electrochemical device and an electronic device.
  • Lithium-ion batteries are widely used in various electronic products such as mobile terminals, power tools, and electric vehicles.
  • button batteries used in wearable devices such as Bluetooth headsets
  • laser welding is usually used to fix the tabs and poles.
  • welding defects are prone to occur, which affects the production efficiency of batteries.
  • the prior art attempts to use conductive glue to replace laser welding.
  • the conductive adhesives in the prior art have the following problems: (1) the shear strength after bonding to metals such as Al, Cu or Ni is low, generally ⁇ 5MPa; (2) in the electrolyte system, the swelling rate and stripping The rate is high, resulting in accelerated capacity decay and accelerated thickness expansion during the battery cycle, and even black spots or purple spots; (3) Poor electrical conductivity, which cannot replace the electrical conductivity of laser welding; (4) Some conductive particles are easily oxidized, For example, Al generates Al 2 O 3 insulation, and Al 3+ will cause the content of heteroions to exceed the standard; (5) The rheological parameters do not meet the dispensing process.
  • the present application provides a conductive glue, an electrochemical device and an electronic device including the conductive glue.
  • the conductive adhesive is used in the electrochemical device instead of laser welding, which can improve the production efficiency of the electrochemical device and also improve the quality of the electrochemical device.
  • the present application provides a conductive adhesive, which includes a base and a conductive filler, wherein the base includes modified epoxy resin, polyurethane and polyimide.
  • the conductive adhesive matrix can form the molecular skeleton of the conductive adhesive, provide mechanical properties and bonding, and allow the conductive filler particles to form channels.
  • the conductive filler particles contact each other, and the tunnel effect forms a certain current path between the particles.
  • the matrix of this application includes three components of modified epoxy resin, polyurethane and polyimide at the same time.
  • the modified epoxy resin can solve the shortcomings of high brittleness and poor toughness of epoxy resin; polyurethane improves impact resistance and damage resistance, shock absorption The effect is good; the high temperature resistance of polyimide can reach 400°C, and it can be used for a long time at 200°C to 300°C.
  • the modified epoxy resin includes carboxyl and/or cyano groups.
  • the active functional group carboxyl group can react with the epoxy group in the epoxy resin; the cyano group (-CN group) has strong polarity and has good miscibility with the epoxy resin.
  • the mass content of the matrix is 50% to 85%.
  • the higher the mass ratio of the matrix the greater the viscosity of the conductive adhesive, the greater the thixotropic index, and the greater the shear strength.
  • the increased shear strength of the conductive adhesive can improve the reliability of the bonding interface, thereby improving the conductivity of the electrochemical device.
  • the mass content of the matrix is 55%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82% %, 85%, or any two of them.
  • the mass content of the conductive filler is 10% to 45%.
  • the mass content of the conductive filler is 10%, 15%, 18%, 20%, 23%, 25%, 28%, 30%, 35%, 38%, 40%, 45%, or any two of them.
  • the mass content of the modified epoxy resin is 70% to 90%.
  • the mass content of the modified epoxy resin is 70%, 72%, 75%, 77%, 80%, 83%, 85%, 88%, 90% or their The range formed by any two of them.
  • the mass content of the polyurethane is 5% to 20%.
  • the mass content of polyimide is 5% to 20%.
  • At least one of the following conditions (x) to (z) is satisfied: (x) the weight average molecular weight of the modified epoxy resin is 300 to 8000; (y) the weight average molecular weight of the polyurethane is 10,000 to 150,000; and (z) the polyimide has a weight average molecular weight of 13,000 to 200,000. According to some embodiments of the present application, the weight average molecular weight of the modified epoxy resin is 500, 1000, 2000, 3000, 3500, 4000, 5000, 6000, 7000 or any two of them.
  • the weight average molecular weight of the polyurethane is 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 130000, 150000 or any two of them.
  • the weight average molecular weight of the polyimide is 13000, 20000, 40000, 50000, 80000, 100000, 120000, 150000, 180000, 200000 or any two of them.
  • the conductive filler includes one or more of Au, Ag, Ni, Cu, Zn, graphite or graphene.
  • the conductive filler satisfies at least one of the following conditions (i) to (iii): (i) the surface morphology of the conductive filler includes one or more of flake, spherical or dendritic; (ii) the particle size of the conductive filler is 0.1 ⁇ m to 100 ⁇ m; and (iii) the bulk density of the conductive filler is 2 g/cm 3 to 15 g/cm 3 .
  • the surface morphology of the conductive filler is spherical.
  • the conductive adhesive further includes other components, and the other components include one or more of curing agent, diluent, accelerator, stress modifier or filler.
  • the curing agent includes one or more of aromatic amine curing agents, aliphatic amine curing agents, alicyclic amine curing agents, polyether amine curing agents or acid anhydride curing agents.
  • the diluent includes one or more of toluene, xylene, benzene or acetone.
  • the stress modifier includes one or more of polysulfide rubber, vinyl resin, and nitrile rubber.
  • the accelerator includes diglycidyl ether, polyglycidyl ether, propylene oxide butyl ether, propylene oxide phenyl ether, dioxypropylene ethyl ether or triglycidyl propylene oxide.
  • the filler includes one or more of alumina, boron nitride, silicon oxide, and titanium oxide.
  • the mass content of the other components is ⁇ 15%. According to some embodiments of the present application, based on the mass of the conductive adhesive, the mass content of the other components is ⁇ 10%.
  • the conductive adhesive has at least one of the following characteristics (a) to (e): (a) the viscosity of the conductive adhesive is 50Pa.s to 300Pa.s; (b) the viscosity of the conductive adhesive is The thixotropic index is 1 to 5; (c) the curing temperature of the conductive adhesive is ⁇ 150°C; (d) the change rate of the width of the conductive adhesive line is ⁇ 75%; and (e) the thermal weight loss rate of the conductive adhesive is ⁇ 0.2%.
  • the viscosity is measured using the viscosity measurement method in GB/T 10247-2008, the temperature is 200°C, and the rotation speed is 1r/min.
  • the thixotropic index is the ratio of viscosity under different speed conditions, that is, the ratio of low-speed viscosity (for example, 0.1r/min) to high-speed viscosity (for example, 1r/min), which reflects that the structure of the fluid under the action of shear force is destroyed and then restored to its original state The quality of the structural capacity.
  • the thixotropic index is the ratio of the viscosity under the test temperature of 200° C.
  • the conductive adhesive has at least one of the following characteristics (A) to (G): (A) the tensile shear bond strength of the conductive adhesive is 5 MPa to 10 MPa; The volume resistance of the adhesive is 0.01 ⁇ cm to 0.1 ⁇ cm; (C) the contact resistance of the conductive adhesive is ⁇ 0.5 ⁇ cm; (D) the total resistance of the conductive adhesive is ⁇ 1m ⁇ ; (E) the electrolyte swelling rate of the conductive adhesive ⁇ 0.1%; and (F) the electrolyte dissolution rate of the conductive adhesive is ⁇ 2%.
  • the electrolyte swelling rate means the weight change rate of the conductive adhesive before and after immersion in the electrolyte solvent
  • the soaking temperature can be 50°C to 70°C, and the soaking time can be 5 days to 8 days.
  • the drying time may be 5 days to 8 days, and the drying temperature may be 80°C to 90°C.
  • the present application provides an electrochemical device, which includes an electrode assembly and a casing, the casing is provided with a pole, and the electrode assembly is provided with a tab, wherein the pole is connected to the pole
  • the ears are connected by the conductive glue described in the first aspect of the present application.
  • the present application provides an electronic device, which includes the electrochemical device according to the second aspect of the present application.
  • the conductive adhesive provided by the present application has high shear strength after bonding, which can ensure the reliability of the bonded interface; on the other hand, its electrochemical performance is stable and can meet the use requirements of lithium-ion batteries.
  • Using the conductive adhesive provided by this application instead of laser welding for electrochemical devices can improve the production efficiency of electrochemical devices and reduce costs.
  • Fig. 1 is a schematic diagram of the application position of the conductive glue in the button battery according to the embodiment of the present application.
  • 1 is the shell cover
  • 2 is the PP glue
  • 3 is the pole
  • 4 is the conductive glue
  • 5 is the bare cell
  • 6 is the shell.
  • the present application provides a conductive adhesive, which includes a base and a conductive filler, wherein the base includes modified epoxy resin, polyurethane and polyimide.
  • the conductive adhesive matrix can form the molecular skeleton of the conductive adhesive, provide mechanical properties and bonding, and allow the conductive filler particles to form channels.
  • the conductive filler particles contact each other, and the tunnel effect forms a certain current path between the particles.
  • the matrix of this application includes three components of modified epoxy resin, polyurethane and polyimide at the same time.
  • the modified epoxy resin can solve the shortcomings of high brittleness and poor toughness of epoxy resin; polyurethane improves impact resistance and damage resistance, shock absorption The effect is good; the high temperature resistance of polyimide can reach 400 °C, and it can be used for a long time at 200 to 300 °C.
  • Polyurethane the full name of polyurethane PU, refers to a heterochain polymer with -NH-COO-characteristic groups. Synthesized from two raw materials: 1 isocyanate, which acts as a hard segment, contains 2 or more -NCO characteristic groups, has a highly unsaturated bond structure with overlapping double bonds, and can react with various compounds containing active hydrogen reaction. Such as hexamethylene diisocyanate (MDI), naphthalene diisocyanate (NDI), etc. 2Polyol, which acts as a soft segment, such as butanediol, polyetherdiol, polyesterdiol, etc.
  • 1 isocyanate which acts as a hard segment, contains 2 or more -NCO characteristic groups, has a highly unsaturated bond structure with overlapping double bonds, and can react with various compounds containing active hydrogen reaction. Such as hexamethylene diisocyanate (MDI), naphthalene diisocyanate (NDI), etc.
  • the glass transition temperature, melting point, modulus, elasticity, and tensile strength of polyurethane can be controlled.
  • the polyurethane includes a soft segment composed of polyether diol or polyester diol and a hard segment composed of isocyanate.
  • the polyurethane has a weight average molecular weight of 10,000 to 150,000.
  • Polyimide is a polycondensation product of dianhydride and diamine, which refers to a polymer whose main chain contains -CO-NH-CO-characteristic groups. It is resistant to high temperature and can be used for a long time at 200 to 300 °C. According to some embodiments of the present application, the polyimide has a weight average molecular weight of 13,000 to 200,000.
  • the modified epoxy resin includes carboxyl and/or cyano groups.
  • the active functional group carboxyl group can react with the epoxy group in the epoxy resin; the cyano group (-CN group) has strong polarity and has good miscibility with the epoxy resin.
  • Epoxy resin is a kind of high molecular polymer, which refers to the general term for a class of polymers containing more than two epoxy groups in the molecule. It is a polycondensation product of epichlorohydrin and bisphenol A or polyol, with a weight average molecular weight of 300 to 7000.
  • the modified epoxy resin is an epoxy resin toughened with liquid carboxy-terminated nitrile rubber (CTBN).
  • CTBN liquid carboxy-terminated nitrile rubber
  • the mass content of the matrix is 50% to 85%.
  • the higher the mass ratio of the matrix the greater the viscosity of the conductive adhesive, the greater the thixotropic index, and the greater the shear strength.
  • the increased shear strength of the conductive adhesive can improve the reliability of the bonding interface, thereby improving the conductivity of the electrochemical device.
  • the mass content of the matrix is 55%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, 82% %, 85%, or any two of them.
  • the mass content of the conductive filler is 10% to 45%.
  • the mass content of the conductive filler is 10%, 15%, 18%, 20%, 23%, 25%, 28%, 30%, 35%, 38%, 40%, 45%, or any two of them.
  • the mass content of the modified epoxy resin is 70% to 90%.
  • the mass content of the modified epoxy resin is 70%, 72%, 75%, 77%, 80%, 83%, 85%, 88%, 90% or their The range formed by any two of them.
  • the mass content of the polyurethane is 5% to 20%.
  • the mass content of polyimide is 5% to 20%.
  • At least one of the following conditions (x) to (z) is satisfied: (x) the weight average molecular weight of the modified epoxy resin is 300 to 8000; (y) the weight average molecular weight of the polyurethane is 10,000 to 150,000; and (z) the polyimide has a weight average molecular weight of 13,000 to 200,000. According to some embodiments of the present application, the weight average molecular weight of the modified epoxy resin is 500, 1000, 2000, 3000, 3500, 4000, 5000, 6000, 7000 or any two of them.
  • the weight average molecular weight of the polyurethane is 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 130000, 150000 or any two of them.
  • the weight average molecular weight of the polyimide is 13000, 20000, 40000, 50000, 80000, 100000, 120000, 150000, 180000, 200000 or any two of them.
  • the conductive filler includes one or more of Au, Ag, Ni, Cu, Zn, graphite or graphene.
  • the conductive filler satisfies at least one of the following conditions (i) to (iii): (i) the surface morphology of the conductive filler includes one or more of flake, spherical or dendritic; (ii ) the conductive filler has a particle size of 0.1 ⁇ m to 100 ⁇ m; and (iii) the conductive filler has a bulk density of 2 g/cm 3 to 15 g/cm 3 .
  • the surface morphology of the conductive filler is spherical.
  • the conductive adhesive further includes other components, and the other components include one or more of curing agent, diluent, accelerator, stress modifier or filler.
  • the curing agent includes one or more of aromatic amine curing agents, aliphatic amine curing agents, alicyclic amine curing agents, polyether amine curing agents or acid anhydride curing agents.
  • the diluent includes one or more of toluene, xylene, benzene or acetone.
  • the stress modifier includes one or more of polysulfide rubber, vinyl resin, and nitrile rubber.
  • the accelerator includes diglycidyl ether, polyglycidyl ether, propylene oxide butyl ether, propylene oxide phenyl ether, dioxypropylene ethyl ether or triglycidyl propylene oxide.
  • the filler includes one or more of alumina, boron nitride, silicon oxide, and titanium oxide.
  • the mass content of the other components is ⁇ 15%. According to some embodiments of the present application, based on the mass of the conductive adhesive, the mass content of the other components is ⁇ 10%.
  • the conductive adhesive has at least one of the following characteristics (a) to (e): (a) the viscosity of the conductive adhesive is 50Pa.s to 300Pa.s; (b) the viscosity of the conductive adhesive is The thixotropic index is 1 to 5; (c) the curing temperature of the conductive adhesive is ⁇ 150° C.; and (d) the change rate of glue line width is ⁇ 75%; (e) the thermal weight loss rate of the conductive adhesive is ⁇ 0.2%.
  • the viscosity is measured using the viscosity measurement method in GB/T 10247-2008, the temperature is 200°C, and the rotation speed is 1r/min.
  • the thixotropic index is the ratio of viscosity under different speed conditions, that is, the ratio of low-speed viscosity (for example, 0.1r/min) to high-speed viscosity (for example, 1r/min), which reflects that the structure of the fluid under the action of shear force is destroyed and then restored to its original state The ability of the structure is good or bad.
  • the thixotropic index is the ratio of the viscosity under the test temperature of 200° C. and the rotational speed of 0.1 r/min to that of the rotational speed of 1 r/min.
  • the conductive adhesive has at least one of the following characteristics (A) to (G): (A) the tensile shear bond strength of the conductive adhesive is 5 MPa to 10 MPa; The volume resistance of the glue is 0.01 ⁇ cm to 0.1 ⁇ cm; (C) the contact resistance of the conductive glue is ⁇ 0.5 ⁇ cm; (D) the total resistance of the conductive glue is ⁇ 1m ⁇ ; and (E) the electrolyte swelling of the conductive glue Rate ⁇ 0.1%; (F) Electrolyte dissolution rate of conductive adhesive ⁇ 2%.
  • the electrolyte swelling rate means the weight change rate of the conductive adhesive before and after immersion in the electrolyte solvent
  • the soaking temperature can be 50°C to 70°C
  • the soaking time can be 5 days to 8 days.
  • the time of drying can be 5 days to 8 days, and the temperature of drying can be 80 °C to 90 °C.
  • the conductive adhesive provided by this application is cured below 150°C. After vertical dispensing, the glue line will not slide down or spread out, ensuring that there is a gap between the glue lines, and ensuring the free shuttle of lithium ions between the tab and the pole. , to meet the requirements of dispensing processing technology.
  • the present application provides an electrochemical device, which includes an electrode assembly and a casing, the casing is provided with a pole, and the electrode assembly is provided with a tab, wherein the pole is connected to the pole
  • the ears are connected by the conductive glue described in the first aspect of the present application.
  • the present application provides an electronic device, which includes the electrochemical device according to the second aspect of the present application.
  • electronic devices of the present application include, but are not limited to, notebook computers, pen-input computers, mobile computers, e-book players, cellular phones, portable fax machines, portable copiers, portable printers, headsets , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini Disc, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, Motorcycle, Assisted Bicycle, Bicycle , Lighting appliances, toys, game consoles, clocks, electric tools, flashlights, cameras or large batteries for household use, etc.
  • Viscosity test by rotation method put the conductive adhesive in a cylinder at a temperature of 200°C, select Brookfield 51# rotor, and rotate at 1rpm. Start the viscometer, read after the reading is stable, repeat the measurement three times, and the maximum difference between it and the average value should not exceed 1.5% of the average value. Take the average of the three measurements as the final viscosity result.
  • Thixotropic index is the ratio of viscosity under different rotational speed conditions, that is, the ratio of low-speed viscosity to high-speed viscosity. It reflects the ability of the fluid to restore the original structure after the structure is destroyed under the action of shear force.
  • the thixotropic index It should be calculated according to the following formula, take two significant figures, and indicate the temperature of the experiment:
  • Shear strength The glued joint can bear the maximum load parallel to the glued surface on the unit area. Test steps:
  • volume resistance put conductive glue in a mold with a depth of 202.54mm and a depth of 50 ⁇ m, put the sample in an environment of color-changing water-absorbing silica gel particles and cure it at 100°C for 2 hours, buckle it upside down on the self-made four-probe mold, press down, The probe is in close contact with the rubber strip, and the resistance value is obtained to calculate the volume resistance.
  • contact resistance apply 202 mm of conductive glue to the bonding part of the Al sheet and the Cu sheet, cure at 100°C for 2 hours, mark the test area on the Al sheet and the Cu sheet respectively, and test the resistance value.
  • the specific steps of the total resistance apply conductive glue between the lug and the pole of the bare cell to obtain a sample with a thickness of 202mm and 50 ⁇ m, and test the resistance value.
  • heating rate is 50°C/min, raised to 100°C, kept for 2.5h, and tested for thermal weight loss.
  • the conductive glue is made into a rubber block and soaked in a lithium-free electrolyte to ensure that the electrolyte is completely submerged in the rubber block. Soak at 60°C for 7 days, then bake at 85°C for 7 days.
  • Swelling rate (weight after soaking for 7 days-weight before soaking)/weight before soaking*100%.
  • Dissolution rate (weight before soaking-weight after drying)/weight before soaking*100%.
  • the CCD records the width of the glue line before curing.
  • Glue line width change rate (width after curing-width before curing)/width before curing*100%.
  • pre-reaction add the mass ratio of 10% to 15% CTBN (carboxyl-terminated liquid nitrile rubber), 85% to 90% epoxy resin (weight average molecular weight is 3500) into the reactor, heat up to 150 ° C, Stir under N 2 protective atmosphere for 12 h.
  • CTBN carboxyl-terminated liquid nitrile rubber
  • epoxy resin weight average molecular weight is 3500
  • CNBT is a telechelic polymer with active functional carboxyl groups at both ends of the molecular chain, which can react with the epoxy group in the epoxy resin, and has a very polar -CN group, which has a relatively strong polarity with the epoxy resin. Good miscibility.
  • Positive electrode sheet mix the positive active material lithium cobaltate, acetylene black, and polyvinylidene fluoride (PVDF) at a mass ratio of 94:3:3, and then add N-methylpyrrolidone (NMP) as a solvent to prepare a solid content Make a 75% slurry and stir well. Apply the slurry evenly on the positive electrode current collector Al foil, dry at 90°C, and cold press to obtain a positive electrode sheet with a positive electrode active material layer thickness of 100 ⁇ m, and then repeat the above on the other surface of the positive electrode sheet step, to obtain a positive electrode sheet coated with a positive electrode active material layer on both sides.
  • NMP N-methylpyrrolidone
  • Negative electrode sheet Mix negative active materials artificial graphite, acetylene black, styrene-butadiene rubber and sodium carboxymethyl cellulose at a mass ratio of 96:1:1.5:1.5, then add deionized water as a solvent, and prepare a solid content of 70 % of the slurry and stir evenly.
  • the slurry is evenly coated on the copper foil of the negative electrode current collector, dried at 110°C, and cold pressed to obtain a negative electrode sheet with a negative electrode active material layer coated on one side with a negative electrode active material layer thickness of 150 ⁇ m, and then on the negative electrode The above coating steps were repeated on the other surface of the pole piece to obtain a negative pole piece coated with a negative electrode active material layer on both sides.
  • Isolation film PE isolation film with a thickness of 7 ⁇ m.
  • the above-mentioned positive pole piece and negative pole piece are respectively positioned on both sides of the separator and wound to obtain a bare battery cell.
  • conductive glue specifically, use a glue dispenser to spray or apply a certain amount of the above-mentioned conductive glue on the cell lugs, and then the battery into the housing, and finally the pole is covered on the tab, and a reliable bond will be formed after the conductive adhesive is cured.
  • the lithium-ion button battery is made.
  • Table 1 shows the composition of the conductive pastes in Examples 1 to 49 and Comparative Examples 1 to 5.
  • Table 2 shows the performance test results of the conductive adhesives in Examples 1 to 49 and Comparative Examples 1 to 5.
  • the mass ratio of the matrix is 50% to 85%, which can meet the use requirements.
  • Example 1 and Comparative Example 5 that the shear strength of the conductive adhesive can be increased from 2.80MPa to 5.20MPa, and the modified epoxy resin has better toughness than the epoxy resin. Therefore, the matrix needs to use modified epoxy resin to meet the requirements of use.
  • the matrix only has epoxy resin or modified epoxy resin, which will lead to high viscosity of conductive adhesive, high thixotropic index, and poor dispensing processability.
  • the matrix is only polyurethane, which will lead to high viscosity of conductive adhesive, high thixotropic index, and poor dispensing processability. Moreover, the swelling rate, dissolution rate, and glue line width change rate are all large, and there is an electrochemical risk.
  • the substrate is only polyimide, which will lead to high viscosity of conductive adhesive, high thixotropic index, and poor dispensing processability. Moreover, the swelling rate, dissolution rate, and glue line width change rate are all large, and there is an electrochemical risk.

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  • Chemical & Material Sciences (AREA)
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Abstract

一种导电胶（4）、电化学装置和电子装置。导电胶（4）包括基体和导电填料，其中基体包括改性环氧树脂、聚氨酯和聚酰亚胺。该导电胶可替代激光焊用于电化学装置，能够提高电化学装置的生产效率，此外还提升了电化学装置的品质。

Description

导电胶、电化学装置和电子装置 技术领域
本申请涉及储能领域，具体涉及一种导电胶、电化学装置和电子装置。
背景技术
锂离子电池被广泛应用于移动终端、电动工具、电动汽车等各类电子产品中。蓝牙耳机等穿戴设备中使用的扣式电池，通常采用激光焊接将极耳与极柱固定。然而，在激光焊接时，很容易出现焊接坏品，影响电池的生产效率。为了解决该问题，现有技术尝试采用导电胶来替代激光焊。
然而，现有技术中的导电胶存在以下问题：(1)对金属例如Al、Cu或Ni粘结后的剪切强度低，一般<5MPa；(2)在电解液体系中，溶胀率和溶出率较大，导致电池循环过程出现容量衰减加速、厚度膨胀加速的现象，甚至产生黑斑或紫斑；(3)导电性差，无法替代激光焊的导电性能；(4)一些导电粒子易被氧化，例如Al，生成Al 2O 3绝缘，且Al 3+会造成杂离子含量超标；(5)流变参数不满足点胶工艺。
因此有必要开发一种改进的导电胶，以用于电化学装置实现导电粘结，替代激光焊。
发明内容
针对现有技术的不足，本申请提供了一种导电胶、包含该导电胶的电化学装置及电子装置。该导电胶替代激光焊用于电化学装置，能够提高电化学装置的生产效率，此外还提升了电化学装置的品质。
在第一方面，本申请提供了一种导电胶，其包括基体和导电填料，其中基体包括改性环氧树脂、聚氨酯和聚酰亚胺。
本申请中，导电胶基体可形成导电胶的分子骨架，提供力学性能和粘结作用，并使导电填料粒子形成通道，导电填料粒子之间相互接触，隧道效应 使粒子间形成一定的电流通路。本申请基体中同时包括改性环氧树脂、聚氨酯和聚酰亚胺这三种组分，改性环氧树脂可解决环氧树脂脆性大、韧性差的缺点；聚氨酯提高耐冲击损伤性能，吸震效果好；聚酰亚胺的耐高温可达400℃，可在200℃至300℃长期使用。
根据本申请的一些实施方式，改性环氧树脂包括羧基和/或氰基。活性官能团羧基可与环氧树脂中的环氧基发生反应；氰基(-CN基)极性强，可与环氧树脂具有较好的混溶性。
根据本申请的一些实施方式，基于导电胶的质量，基体的质量含量为50％至85％。基体质量比例越高，导电胶的粘度越大，触变指数变大，剪切强度也随之变大。导电胶的剪切强度增大，可以提高粘结界面的可靠性，进而提升电化学装置的导电性能。根据本申请的一些实施方式，基于导电胶的质量，基体的质量含量为55％、60％、62％、65％、68％、70％、72％、75％、78％、80％、82％、85％或它们中任意二者构成的范围。
根据本申请的一些实施方式，基于导电胶的质量，导电填料的质量含量为10％至45％。导电填料质量比例越高，电阻越小，导电性越好。根据本申请的一些实施方式，基于导电胶的质量，导电填料的质量含量为10％、15％、18％、20％、23％、25％、28％、30％、35％、38％、40％、45％或它们中任意二者构成的范围。
根据本申请的一些实施方式，基于基体的质量，改性环氧树脂的质量含量为70％至90％。改性环氧树脂比例越高，剪切强度增大。根据本申请的一些实施方式，基于基体的质量，改性环氧树脂的质量含量为70％、72％、75％、77％、80％、83％、85％、88％、90％或它们中任意二者构成的范围。
根据本申请的一些实施方式，基于基体的质量，聚氨酯的质量含量为5％至20％。聚氨酯比例越高，耐冲击损伤性能越高，导电胶的吸震效果越好，进而可提高电化学装置的抗震动、跌落和滚筒性能。
根据本申请的一些实施方式，基于基体的质量，聚酰亚胺的质量含量为5％至20％。聚酰亚胺比例越高，导电胶的耐温性能越好，进而可提高电化学装置的高温安全性能。
根据本申请的一些实施方式，满足如下条件(x)至(z)中的至少一者： (x)改性环氧树脂的重均分子量为300至8000；(y)聚氨酯的重均分子量为10000至150000；和(z)聚酰亚胺的重均分子量为13000至200000。根据本申请的一些实施方式，改性环氧树脂的重均分子量为500、1000、2000、3000、3500、4000、5000、6000、7000或它们中任意二者构成的范围。根据本申请的一些实施方式，聚氨酯的重均分子量为10000、20000、30000、40000、50000、60000、70000、80000、90000、100000、130000、150000或它们中任意二者构成的范围。根据本申请的一些实施方式，聚酰亚胺的重均分子量为13000、20000、40000、50000、80000、100000、120000、150000、180000、200000或它们中任意二者构成的范围。
根据本申请的一些实施方式，导电填料包括Au、Ag、Ni、Cu、Zn、石墨或石墨烯中的一种或多种。
根据本申请的一些实施方式，导电填料满足以下条件(i)至(iii)中的至少一者：(i)导电填料表面形貌包括片状、球状或枝状中的一种或多种；(ii)导电填料的粒径为0.1μm至100μm；和(iii)导电填料的堆积密度为2g/cm 3至15g/cm 3。通过调控导电填料表面形貌、粒径分布、堆积密度可以提高导电胶的导电性，进而提升电化学装置的品质。根据本申请的一些优选实施方式，导电填料表面形貌为球状。
根据本申请的一些实施方式，所述导电胶还包括其他成分，所述其他成分包括固化剂、稀释剂、促进剂、应力改性剂或填料中的一种或多种。
根据本申请的一些实施方式，所述固化剂包括芳香胺固化剂、脂肪胺固化剂、脂环胺固化剂、聚醚胺固化剂或酸酐固化剂中的一种或多种。根据本申请的一些实施方式，所述稀释剂包括甲苯、二甲苯、苯或丙酮中的一种或多种。根据本申请的一些实施方式，所述应力改性剂包括聚硫橡胶、乙烯树脂、丁腈橡胶中的一种或多种。根据本申请的一些实施方式，所述促进剂包括二缩水甘油醚、多缩水甘油醚、环氧丙烷丁基醚、环氧丙烷苯基醚、二环氧丙烷乙基醚或三环氧丙烷丙基醚中的一种或多种。根据本申请的一些实施方式，所述填料包括氧化铝、氮化硼或氧化硅、氧化钛中的一种或多种。
根据本申请的一些实施方式，基于导电胶的质量，所述其他成分的质量含量≤15％。根据本申请的一些实施方式，基于导电胶的质量，所述其他成 分的质量含量≤10％。
根据本申请的一些实施方式，所述导电胶具有如下特性(a)至(e)中的至少一者：(a)导电胶的粘度为50Pa.s至300Pa.s；(b)导电胶的触变指数为1至5；(c)导电胶的固化温度≤150℃；(d)导电胶胶线宽度变化率≤75％；和(e)导电胶的热失重率≤0.2％。根据本申请的一些实施方式，粘度采用GB/T 10247-2008中的粘度测量方法进行测定，温度200℃，转速1r/min。触变指数是不同转速条件下粘度的比值，即低速粘度(例如0.1r/min)与高速粘度(例如1r/min)的比值，反映流体在剪切力的作用下结构被破坏后恢复原有结构能力的好坏。根据本申请的一些实施方式，触变指数为测试温度200℃，转速0.1r/min的条件下与转速1r/min的条件下粘度的比值。导电胶胶线宽度变化率指导电胶固化前和固化后的宽度变化率，即胶线宽度变化率＝(固化后宽度-固化前宽度)/固化前宽度×100％。
根据本申请的一些实施方式，所述导电胶具有如下特性(A)至(G)中的至少一者：(A)导电胶的拉伸剪切粘结强度为5MPa至10MPa；(B)导电胶的体积电阻为0.01Ω·cm至0.1Ω·cm；(C)导电胶的接触电阻≤0.5Ω·cm；(D)导电胶的总电阻≤1mΩ；(E)导电胶的电解液溶胀率≤0.1％；和(F)导电胶的电解液溶出率≤2％。
本申请中，电解液溶胀率表示导电胶在电解液溶剂中进行浸泡前后的重量变化率，计算式可以为溶胀率＝(浸泡后重量-浸泡前重量)/浸泡前重量×100％。电解液溶出率表示导电胶在电解液溶剂中进行浸泡并烘干后的重量变化率，计算式可以为溶出率＝(浸泡前重量-烘干后重量)/浸泡前重量×100％。浸泡的温度可以是50℃至70℃，浸泡的时间可以是5天至8天。烘干的时间可以是5天至8天，烘干的温度可以是80℃至90℃。电解液溶剂包括碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸二乙酯(DEC)和丙酸乙酯(EP)，质量比例如EC∶PC∶DEC∶EP＝3∶1∶3∶3。
在第二方面，本申请提供了一种电化学装置，该电化学装置包括电极组件和壳体，壳体设置有极柱，电极组件设置有极耳，其中，所述极柱与所述极耳通过本申请第一方面所述的导电胶连接。
在第三方面，本申请提供了一种电子装置，其包括根据本申请第二方面所述的电化学装置。
本申请提供的导电胶粘结后的剪切强度大，可以保证粘结界面的可靠性；另一方面，其电化学性能稳定，能够满足锂离子电池的使用要求。采用本申请提供的导电胶替代激光焊用于电化学装置，可提高电化学装置的生产效率，降低成本。
附图说明
图1是根据本申请实施方式的导电胶在扣式电池中应用位置的示意图，图1中1为壳盖、2为PP胶、3为极柱、4为导电胶、5为裸电芯、6为壳体。
具体实施方式
下面结合具体实施方式，进一步阐述本申请。应理解，这些具体实施方式仅用于说明本申请。
在第一方面，本申请提供了一种导电胶，其包括基体和导电填料，其中基体包括改性环氧树脂、聚氨酯和聚酰亚胺。
本申请中，导电胶基体可形成导电胶的分子骨架，提供力学性能和粘结作用，并使导电填料粒子形成通道，导电填料粒子之间相互接触，隧道效应使粒子间形成一定的电流通路。本申请基体中同时包括改性环氧树脂、聚氨酯和聚酰亚胺这三种组分，改性环氧树脂可解决环氧树脂脆性大、韧性差的缺点；聚氨酯提高耐冲击损伤性能，吸震效果好；聚酰亚胺的耐高温可达400℃，可在200至300℃长期使用。
聚氨酯，全称聚氨基甲酸酯PU，是指带有-NH-COO-特征基团的杂链聚合物。由两种原料合成：①异氰酸酯，起着硬段的作用，含有2个或多个-NCO特征基团，具有重叠双键排列的高度不饱和键结构，能与各种含活泼氢的化合物进行反应。如六亚甲基二异氰酸酯(MDI)、萘二异氰酸酯(NDI)等。②多元醇，起着软段的作用，如丁二醇、聚醚二醇、聚酯二醇等。通过调整 软硬段的比例和种类，来控制聚氨酯的玻璃化温度、熔点、模量、弹性、抗张强度等。根据本申请的一些实施方式，聚氨酯包括聚醚二醇或聚酯二醇构成的软段以及异氰酸酯构成的硬段。根据本申请的一些实施方式，聚氨酯的重均分子量为10000至150000。
聚酰亚胺是二酐和二胺的缩聚物，是指主链含有-CO-NH-CO-特征基团的聚合物，耐高温，可在200至300℃长期使用。根据本申请的一些实施方式，聚酰亚胺的重均分子量13000至200000。
根据本申请的一些实施方式，改性环氧树脂包括羧基和/或氰基。活性官能团羧基可与环氧树脂中的环氧基发生反应；氰基(-CN基)极性强，可与环氧树脂具有较好的混溶性。环氧树脂是一种高分子聚合物是指分子中含有两个以上环氧基团的一类聚合物的总称。它是环氧氯丙烷与双酚A或多元醇的缩聚产物，重均分子量为300至7000。
根据本申请的一些实施方式，改性环氧树脂是用液体端羧基丁腈橡胶(CTBN)增韧的环氧树脂。
根据本申请的一些实施方式，基于导电胶的质量，基体的质量含量为50％至85％。基体质量比例越高，导电胶的粘度越大，触变指数变大，剪切强度也随之变大。导电胶的剪切强度增大，可以提高粘结界面的可靠性，进而提升电化学装置的导电性能。根据本申请的一些实施方式，基于导电胶的质量，基体的质量含量为55％、60％、62％、65％、68％、70％、72％、75％、78％、80％、82％、85％或它们中任意二者构成的范围。
根据本申请的一些实施方式，基于导电胶的质量，导电填料的质量含量为10％至45％。导电填料质量比例越高，电阻越小，导电性越好。根据本申请的一些实施方式，基于导电胶的质量，导电填料的质量含量为10％、15％、18％、20％、23％、25％、28％、30％、35％、38％、40％、45％或它们中任意二者构成的范围。
根据本申请的一些实施方式，基于基体的质量，改性环氧树脂的质量含量为70％至90％。改性环氧树脂比例越高，剪切强度增大。根据本申请的一些实施方式，基于基体的质量，改性环氧树脂的质量含量为70％、72％、75％、77％、80％、83％、85％、88％、90％或它们中任意二者构成的范围。
根据本申请的一些实施方式，基于基体的质量，聚氨酯的质量含量为5％至20％。聚氨酯比例越高，耐冲击损伤性能越高，导电胶的吸震效果越好，进而可提高电化学装置的抗震动、跌落、滚筒性能。
根据本申请的一些实施方式，基于基体的质量，聚酰亚胺的质量含量为5％至20％。聚酰亚胺比例越高，导电胶的耐温性能越好，进而可提高电化学装置的高温安全性能。
根据本申请的一些实施方式，满足如下条件(x)至(z)中的至少一者：(x)改性环氧树脂的重均分子量为300至8000；(y)聚氨酯的重均分子量为10000至150000；和(z)聚酰亚胺的重均分子量为13000至200000。根据本申请的一些实施方式，改性环氧树脂的重均分子量为500、1000、2000、3000、3500、4000、5000、6000、7000或它们中任意二者构成的范围。根据本申请的一些实施方式，聚氨酯的重均分子量为10000、20000、30000、40000、50000、60000、70000、80000、90000、100000、130000、150000或它们中任意二者构成的范围。根据本申请的一些实施方式，聚酰亚胺的重均分子量为13000、20000、40000、50000、80000、100000、120000、150000、180000、200000或它们中任意二者构成的范围。
根据本申请的一些实施方式，导电填料包括Au、Ag、Ni、Cu、Zn、石墨或石墨烯中的一种或多种。
根据本申请的一些实施方式，导电填料满足以下条件(i)至(iii)中的至少一者：(i)导电填料表面形貌包括片状、球状或枝状一种或多种；(ii)导电填料的粒径为0.1μm至100μm；和(iii)导电填料的堆积密度2g/cm 3至15g/cm 3。通过调控导电填料表面形貌、粒径分布、堆积密度可以提高导电胶的导电性，进而提升电化学装置的品质。根据本申请的一些优选实施方式，导电填料表面形貌为球状。
根据本申请的一些实施方式，所述导电胶还包括其他成分，所述其他成分包括固化剂、稀释剂、促进剂、应力改性剂或填料中的一种或多种。
根据本申请的一些实施方式，所述固化剂包括芳香胺固化剂、脂肪胺固化剂、脂环胺固化剂、聚醚胺固化剂或酸酐固化剂中的一种或多种。根据本申请的一些实施方式，所述稀释剂包括甲苯、二甲苯、苯或丙酮中的一种或 多种。根据本申请的一些实施方式，所述应力改性剂包括聚硫橡胶、乙烯树脂、丁腈橡胶中的一种或多种。根据本申请的一些实施方式，所述促进剂包括二缩水甘油醚、多缩水甘油醚、环氧丙烷丁基醚、环氧丙烷苯基醚、二环氧丙烷乙基醚或三环氧丙烷丙基醚中的一种或多种。根据本申请的一些实施方式，所述填料包括氧化铝、氮化硼或氧化硅、氧化钛中的一种或多种。
根据本申请的一些实施方式，基于导电胶的质量，所述其他成分的质量含量≤15％。根据本申请的一些实施方式，基于导电胶的质量，所述其他成分的质量含量≤10％。
根据本申请的一些实施方式，所述导电胶具有如下特性(a)至(e)中的至少一者：(a)导电胶的粘度为50Pa.s至300Pa.s；(b)导电胶的触变指数为1至5；(c)导电胶的固化温度≤150℃；和(d)胶线宽度变化率≤75％；(e)导电胶的热失重率≤0.2％。根据本申请的一些实施方式，粘度采用GB/T 10247-2008中的粘度测量方法进行测定，温度200℃，转速1r/min。触变指数是不同转速条件下粘度的比值，即低速粘度(例如0.1r/min)与高速粘度(例如1r/min)的比值，反映流体在剪切力的作用下结构被破坏后恢复原有结构的能力的好坏。根据本申请的一些实施方式，触变指数为测试温度200℃，转速0.1r/min的条件下与转速1r/min的条件下粘度的比值。胶线宽度变化率指导电胶固化前和固化后的宽度变化率，即胶线宽度变化率＝(固化后宽度-固化前宽度)/固化前宽度×100％。
根据本申请的一些实施方式，所述导电胶具有如下特性(A)至(G)中的至少一者：(A)导电胶的拉伸剪切粘结强度为5MPa至10MPa；(B)导电胶的体积电阻为0.01Ω·cm至0.1Ω·cm；(C)导电胶的接触电阻≤0.5Ω·cm；(D)导电胶的总电阻≤1mΩ；和(E)导电胶的电解液溶胀率≤0.1％；(F)导电胶的电解液溶出率≤2％。
本申请中，电解液溶胀率表示导电胶在电解液溶剂中进行浸泡前后的重量变化率，计算式可以为溶胀率＝(浸泡后重量-浸泡前重量)/浸泡前重量×100％。电解液溶出率表示导电胶在电解液溶剂中进行浸泡并烘干后的重量变化率，计算式可以为溶出率＝(浸泡前重量-烘干后重量)/浸泡前重量×100％。浸泡的温度可以是50℃至70℃，浸泡的时间可以是5天至8天。烘干的时间 可以是5天至8天，烘干的温度可以是80℃至90℃。电解液溶剂包括碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸二乙酯(DEC)和丙酸乙酯(EP)，质量比例如EC∶PC∶DEC∶EP＝3∶1∶3∶3。
本申请提供的导电胶在150℃以下固化，垂直点胶后，胶线不会向下滑移或摊开，保证胶线之间存在间隙，确保极耳和极柱之间的锂离子自由穿梭，满足点胶加工工艺的要求。
在第二方面，本申请提供了一种电化学装置，该电化学装置包括电极组件和壳体，壳体设置有极柱，电极组件设置有极耳，其中，所述极柱与所述极耳通过本申请第一方面所述的导电胶连接。
在第三方面，本申请提供了一种电子装置，其包括根据本申请第二方面所述的电化学装置。
本申请的电子设备或装置没有特别限定。在一些实施例中，本申请的电子设备包括但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机或家庭用大型蓄电池等。
下面结合实施例进一步阐述本申请。应理解，这些实施例仅用于说明本申请而不用于限制本申请的范围。
一、测试方法
1、粘度测量方法GB/T 10247-2008
设备名称：粘度计，厂家：博勒飞，型号：DV2T。测量范围：>1.5mpa.s，精度：±1％FS。
旋转法测试粘度：将导电胶置于圆筒中，温度200℃，选用博勒飞51#转子、1rpm转速。启动粘度计，待示数稳定后读数，重复测量三次，其与均 值的最大差值不应超过均值的1.5％。取三次测量值的均值作为最终粘度结果。
2、触变指数测试
触变指数是不同转速条件下粘度的比值，即低速粘度与高速粘度的比值。反映流体在剪切力的作用下结构被破坏后恢复原有结构的能力的好坏。
设备名称：粘度计，厂家：博勒飞，型号：DV2T。测量范围：>1.5mpa.s，精度：±1％FS。
测试步骤：
a)将盛有试样的容器放入已升温至200℃的恒温槽中，并保持温度均匀。
b)博勒飞51#转子垂直浸入试样中的部位，并使液面达到转子液位标线。
c)转速设置为0.1r/min，开动粘度计，读取旋转的指针稳定后的第一次读数。关闭马达后再重新起动两次，分别读取指针第二次和第三次稳定后的读数，取平均值记为η0.1。
d)将转速由0.1r/min更换为1r/min，重复上述步骤，测量其指针稳定后的读数，共三次，取平均值记为η1。
触变指数It应按下式计算，取两位有效数，并应注明实验的温度：
It＝η0.1/η1
3、剪切试验
剪切强度：胶接头在单位面积上能承受平行于胶接面的最大负荷。测试步骤：
将Al片、Cu片、Ni片三种试样制成12.7mm×25.4mm的片状规格，再选取Al片和Cu片、Al片和Ni片、Cu片和Ni片三种样品组合方式，分在在其中间界面涂布导电胶。100℃固化2h后，在万能试验机上以10mm/min的拉剪速度测试，直至界面破坏。每种试样组合测试5个样品，取拉伸剪切强度的算术平均值即为导电胶水粘接后的剪切强度。
4、电阻测试方法
四探针电阻率测试仪，厂家：瑞柯，型号：FT-340。四根探针的针尖在同一直线上，并且间距相等，都是S，一般采用0.5mm的间距，不同的探针间距需要对测量结果做相应的校正。通过厚度数值的设置，计算出不同的样 品厚度对电阻率的影响。
体积电阻具体步骤：在202.54mm深度50μm的模具中装入导电胶，把试样放入变色吸水硅胶颗粒的环境中100℃固化2h，倒扣在自制的四探针模具上，向下按压，使探针与胶条紧密接触，得到电阻值从而计算出体积电阻。
接触电阻具体步骤：Al片和Cu片贴合部位涂202mm的导电胶水，100℃固化2h，分别在Al片、Cu片上标记测试区域，测试电阻值。
总电阻具体步骤：将导电胶水涂在裸电芯的极耳与极柱之间，得到202mm厚度50μm的试样，测试电阻值。
5、热失重测试方法
设备名称：热质联用仪DSC/TG-MS，型号：STA449F3-QMS403C，测试依据：GB/T 13464-2008物质热稳定性的热分析方法，检测能力：室温～800℃，升温速率0.1～50℃/min，TG分辨率0.1ug。
具体步骤：升温速率50℃/min，升至100℃，保持2.5h，测试热失重。
6、溶出率测试
将导电胶水制成胶块浸泡在无锂盐电解液中，保证电解液完全浸没胶块。先在60℃浸泡7天，再85℃烘烤7天。
其中，无锂盐电解液的有机溶剂为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸二乙酯(DEC)、丙酸乙酯(EP)，且质量比EC∶PC∶DEC∶EP＝3∶1∶3∶3。
溶胀率＝(浸泡7天后重量-浸泡前重量)/浸泡前重量*100％。
溶出率＝(浸泡前重量-烘干后重量)/浸泡前重量*100％。
7、胶线宽度变化率
将导电胶用点胶机在玻璃片上完成点胶，室温静置10min，确保胶线粘度稳定，CCD记录固化前胶线宽度。
100℃固化2h，确保整个固化过程胶线保持竖直状态，在自身重力下，胶线宽度会发生变化，CCD记录测量后胶线宽度。
胶线宽度变化率＝(固化后宽度-固化前宽度)/固化前宽度*100％。
二、实施例和对比例
1、导电胶水的制备
1)、预反应：将质量比例10％至15％的CTBN(端羧基液体丁腈橡胶)、85％至90％的环氧树脂(重均分子量为3500)加入反应器，升温到150℃，在N 2保护气氛中搅拌12h。
机理：CNBT是遥爪式高聚物，分子链两端是活性官能团羧基，可与环氧树脂中的环氧基发生反应，且具有极性很强的-CN基，与环氧树脂具有较好的混溶性。
2)、将固化剂(如芳香胺固化剂、脂肪胺固化剂、脂环胺固化剂、聚醚胺固化剂、酸酐固化剂等)加入到预反应生成的“环氧-CTBN-环氧”加成物中，固化2h，得到改性环氧树脂。
3)、将质量比例50％至85％的改性环氧树脂、聚氨酯(重均分子量为80000)、聚酰亚胺(重均分子量为10000)三者按照质量比例(70％至90％)：(5％至20％)：(5％至20％)加入反应器，并添加质量比例10％至45％的导电填料(Au、Ag、Ni、Cu、Al、Zn、石墨、石墨烯等一种或多种)，升温到200℃，在N 2保护气氛中进行搅拌12h。
4)、再加入质量比例5％至10％的其他成分(固化剂、稀释剂、应力改性剂、促进剂、氧化物)，固化2h，得到导电胶水。
实施例和对比例具体组分参见表1。
2、电池制备方法
正极极片：将正极活性材料钴酸锂、乙炔黑、聚偏二氟乙烯(PVDF)按质量比94：3：3混合，然后加入N-甲基吡咯烷酮(NMP)作为溶剂，调配成固含量为75％的浆料，并搅拌均匀。将浆料均匀涂布在正极集流体Al箔上，90℃条件下烘干，冷压后得到正极活性材料层厚度为100μm的正极极片，然后在该正极极片的另一个表面上重复以上步骤，得到双面涂布有正极活性材料层的正极极片。
负极极片：将负极活性材料人造石墨、乙炔黑、丁苯橡胶及羧甲基纤维素钠按质量比96：1：1.5：1.5混合，然后加入去离子水作为溶剂，调配成固 含量为70％的浆料，并搅拌均匀。将浆料均匀涂布在负极集流体铜箔上，110℃条件下烘干，冷压后得到负极活性材料层厚度为150μm的单面涂布负极活性材料层的负极极片，然后在该负极极片的另一个表面上重复以上涂布步骤，得到双面涂布有负极活性材料层的负极极片。
隔离膜：厚度7μm的PE隔离膜。
电解液的有机溶剂为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸二乙酯(DEC)、丙酸乙酯(EP)，且质量比EC∶PC∶DEC∶EP＝3∶1∶3∶3，溶质为六氟磷酸锂(LiPF 6)，LiPF 6的浓度为1mol/L。
电池制备：将上述正极极片、负极极片分别位于隔离膜两侧进行卷绕，得到裸电芯。将裸电芯装入钢壳，裸电芯极耳与极柱采用导电胶连接固定(具体为用点胶机在电芯极耳处喷或涂一定量的上述制备的导电胶水，之后电芯入壳体，最后极柱覆盖在极耳处，待导电胶固化即形成可靠粘接)。然后经顶侧封、真空烘烤、注液、化成、容量、抽气等工序，制成锂离子扣式电池。
三、测试结果
表1示出了实施例1至实施例49和对比例1至对比例5中的导电胶的组成。表2示出了实施例1至实施例49和对比例1至对比例5中的导电胶的性能测试结果。
Figure PCTCN2021139726-appb-000001
Figure PCTCN2021139726-appb-000002
Figure PCTCN2021139726-appb-000003
Figure PCTCN2021139726-appb-000004
Figure PCTCN2021139726-appb-000005
Figure PCTCN2021139726-appb-000006
Figure PCTCN2021139726-appb-000007
通过表1和表2可以看出，
1、基体总质量比例为40％时，导电胶的剪切强度只有4.35MPa，不能实现可靠粘结。基体总质量比例为95％时，导电胶触变指数7.90，点胶加工性差，且导电填料的质量比例低，造成电阻偏大。因此，基体质量比例在50％～85％，可满足使用要求。
2、实施例1和对比例5看出，导电胶的剪切强度可由2.80MPa提高到5.20MPa，改性环氧树脂相比环氧树脂韧性更好。因此，基体需选用改性环氧树脂，才能满足使用要求。
3、基体只有环氧树脂或改性环氧树脂，会导致导电胶粘度大，触变指数大，点胶加工性差。
4、基体只有聚氨酯，会导致导电胶粘度大，触变指数大，点胶加工性差。且溶胀率、溶出率、胶线宽度变化率均较大，存在电化学风险。
5、基体只有聚酰亚胺，会导致导电胶粘度大，触变指数大，点胶加工性差。且溶胀率、溶出率、胶线宽度变化率均较大，存在电化学风险。
6、基体中改性环氧树脂：聚氨酯：聚酰亚胺组成＝(70％～90％)：(5％～20％)：(5％～20％)，可实现导电可靠粘结。
以上各实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述各实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请技术方案的范围。

Claims (10)

  1. 一种导电胶，包括基体和导电填料，其中所述基体包括改性环氧树脂、聚氨酯和聚酰亚胺。
  2. 根据权利要求1所述的导电胶，其中，基于所述导电胶的质量，所述基体的质量含量为50％至85％，所述导电填料的质量含量为10％至45％。
  3. 根据权利要求1所述的导电胶，其中，基于所述基体的质量，所述改性环氧树脂的质量含量为70％至90％，所述聚氨酯的质量含量为5％至20％，所述聚酰亚胺的质量含量为5％至20％。
  4. 根据权利要求1所述的导电胶，其中，所述改性环氧树脂包括羧基和/或氰基。
  5. 根据权利要求1所述的导电胶，其中，所述导电填料包括Au、Ag、Ni、Cu、Zn、石墨或石墨烯中的一种或多种。
  6. 根据权利要求1所述的导电胶，其中，所述导电填料满足以下条件(i)至(iii)中的至少一者：
    (i)所述导电填料表面形貌包括片状、球状或枝状中的一种或多种；
    (ii)所述导电填料的粒径为0.1μm至100μm；
    (iii)所述导电填料的堆积密度2g/cm 3至15g/cm 3。
  7. 根据权利要求1所述的导电胶，其中，所述导电胶具有如下特性(a)至(e)中的至少一者：
    (a)所述导电胶的粘度为50Pa.s至300Pa.s；
    (b)所述导电胶的触变指数为1至5；
    (c)所述导电胶的固化温度≤150℃；
    (d)所述导电胶胶线宽度变化率≤75％；
    (e)所述导电胶的热失重率≤0.2％。
  8. 根据权利要求1所述的导电胶，其中，所述导电胶具有如下特性(A)至(F)中的至少一者：
    (A)所述导电胶的拉伸剪切粘结强度为5MPa至10MPa；
    (B)所述导电胶的体积电阻为0.01Ω·cm至0.1Ω·cm；
    (C)所述导电胶的接触电阻≤0.5Ω·cm；
    (D)所述导电胶的总电阻≤1mΩ；
    (E)所述导电胶的电解液溶胀率≤0.1％；
    (F)所述导电胶的电解液溶出率≤2％。
  9. 一种电化学装置，包括电极组件和壳体，壳体设置有极柱，电极组件设置有极耳，其中，所述极柱与所述极耳通过权利要求1-8中任一项所述的导电胶连接。
  10. 一种电子装置，包括根据权利要求9所述的电化学装置。
PCT/CN2021/139726 2021-12-20 2021-12-20 导电胶、电化学装置和电子装置 WO2023115264A1 (zh)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007051272A (ja) * 2005-07-19 2007-03-01 Daisee Kogyo Kk 耐熱性導電性接着剤
JP2007262260A (ja) * 2006-03-29 2007-10-11 Nok Corp 接着剤組成物
CN104293229A (zh) * 2014-10-21 2015-01-21 济南圣泉集团股份有限公司 一种导电胶及其制备方法
CN105462514A (zh) * 2015-11-24 2016-04-06 苏州盖德精细材料有限公司 一种高性能聚酰亚胺改性环氧树脂导电胶及其制备方法
CN110616057A (zh) * 2019-09-25 2019-12-27 宜兴市普利泰电子材料有限公司 一种流水线蓄电池用密封胶的制备和使用方法
CN112961624A (zh) * 2021-01-29 2021-06-15 天津市捷威动力工业有限公司 一种导电焊接胶、导电双面胶带及应用
WO2021142748A1 (zh) * 2020-01-17 2021-07-22 深圳市首骋新材料科技有限公司 一种环氧树脂导电胶及其制备方法和应用
CN113555602A (zh) * 2021-08-19 2021-10-26 多氟多新能源科技有限公司 一种新型圆柱锂离子电池及其制作方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007051272A (ja) * 2005-07-19 2007-03-01 Daisee Kogyo Kk 耐熱性導電性接着剤
JP2007262260A (ja) * 2006-03-29 2007-10-11 Nok Corp 接着剤組成物
CN104293229A (zh) * 2014-10-21 2015-01-21 济南圣泉集团股份有限公司 一种导电胶及其制备方法
CN105462514A (zh) * 2015-11-24 2016-04-06 苏州盖德精细材料有限公司 一种高性能聚酰亚胺改性环氧树脂导电胶及其制备方法
CN110616057A (zh) * 2019-09-25 2019-12-27 宜兴市普利泰电子材料有限公司 一种流水线蓄电池用密封胶的制备和使用方法
WO2021142748A1 (zh) * 2020-01-17 2021-07-22 深圳市首骋新材料科技有限公司 一种环氧树脂导电胶及其制备方法和应用
CN112961624A (zh) * 2021-01-29 2021-06-15 天津市捷威动力工业有限公司 一种导电焊接胶、导电双面胶带及应用
CN113555602A (zh) * 2021-08-19 2021-10-26 多氟多新能源科技有限公司 一种新型圆柱锂离子电池及其制作方法

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