WO2022000308A1 - 一种双极性集流体、电化学装置及电子装置 - Google Patents

一种双极性集流体、电化学装置及电子装置 Download PDF

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WO2022000308A1
WO2022000308A1 PCT/CN2020/099422 CN2020099422W WO2022000308A1 WO 2022000308 A1 WO2022000308 A1 WO 2022000308A1 CN 2020099422 W CN2020099422 W CN 2020099422W WO 2022000308 A1 WO2022000308 A1 WO 2022000308A1
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current collector
bipolar current
metal
thickness
bipolar
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PCT/CN2020/099422
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English (en)
French (fr)
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张益博
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宁德新能源科技有限公司
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Priority to CN202080099184.5A priority Critical patent/CN115362579A/zh
Priority to AU2020455613A priority patent/AU2020455613B2/en
Priority to PCT/CN2020/099422 priority patent/WO2022000308A1/zh
Priority to EP20943532.0A priority patent/EP4160751A1/en
Priority to JP2022565719A priority patent/JP2023523064A/ja
Publication of WO2022000308A1 publication Critical patent/WO2022000308A1/zh
Priority to US18/148,774 priority patent/US20230134298A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/134—Electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/663—Selection of materials containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/666—Composites in the form of mixed materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/668—Composites of electroconductive material and synthetic resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H01M4/80—Porous plates, e.g. sintered carriers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/02—Details
    • H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
    • H01M8/0204—Non-porous and characterised by the material
    • H01M8/0206—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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/029—Bipolar electrodes
    • 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 the field of batteries, in particular to a bipolar current collector, an electrochemical device and an electronic device comprising the bipolar current collector.
  • Lithium-ion batteries are widely used in consumer electronics due to their large volume and mass energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight. With the rapid development of electric vehicles and mobile electronic devices in recent years, people have higher and higher requirements for battery energy density, safety performance, cycle performance, etc., and it is necessary to develop new lithium-ion batteries with comprehensive performance improvements.
  • the purpose of the present invention is to provide a bipolar current collector, an electrochemical device and an electronic device, so as to improve the output voltage of the electrochemical device.
  • a first aspect of the present invention provides a bipolar current collector, which includes a porous substrate, a first metal M, and a second metal N, wherein the porous substrate has the first metal M on one surface and the second metal on the other surface. N, at least one of the first metal M or the second metal N exists in the interior of the porous matrix;
  • the material of the porous matrix includes at least one of carbon material, polymer material or third metal;
  • the porous matrix has a porosity of 20% to 90%.
  • the carbon material comprises single-wall carbon nanotube film, multi-wall carbon nanotube film, carbon felt, porous carbon film, carbon black, acetylene black, fullerene, conductive graphite or graphite at least one of alkenes.
  • the polymer material includes polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether ether ketone, polyethylene terephthalate Imide, polyamide, polyethylene glycol, polyamideimide, polycarbonate, cyclic polyolefin, polyphenylene sulfide, polyvinyl acetate, polytetrafluoroethylene, polymethylene naphthalene, polyvinylidene Vinyl difluoride, polyethylene naphthalate, polypropylene carbonate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-chlorotrifluoroethylene), silicone, vinylon , at least one of polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyphenylene ether, polyester, polysulfone or derivatives thereof.
  • the third metal, the first metal M, and the second metal N for the porous matrix each independently comprise Cu, Al, Ni, Ti, Ag, Au, Pt, stainless steel or at least one of its alloys.
  • the thickness of the layer formed by the first metal M on the surface of the porous substrate is 0.95 ⁇ m to 900 ⁇ m; the thickness of the layer formed by the second metal N on the surface of the porous substrate is 0.95 ⁇ m to 900 ⁇ m 900 ⁇ m.
  • the bipolar current collector has a thickness of 2 ⁇ m to 1000 ⁇ m.
  • the bipolar current collector has a surface roughness of 0.05 ⁇ m to 10 ⁇ m.
  • the thickness ratio of the layer of the first metal M formed on the surface of the porous substrate to the layer of the second metal N formed on the surface of the porous substrate is 0.05 to 20.
  • the Z-direction electron resistivity of the bipolar current collector is 2.00 ⁇ 10 ⁇ 10 ⁇ cm to 2.00 ⁇ 10 ⁇ 4 ⁇ cm.
  • the bipolar current collector satisfies at least one of the following characteristics:
  • the thickness of the bipolar current collector is 5 ⁇ m to 50 ⁇ m;
  • the surface roughness of the bipolar current collector is 0.2 ⁇ m to 5 ⁇ m;
  • the thickness ratio of the layer formed by the first metal M on the surface of the porous substrate to the layer formed by the second metal N on the surface of the porous substrate is 0.2 to 5;
  • the Z-direction electron resistivity of the bipolar current collector is 2.00 ⁇ 10 -10 ⁇ cm to 2.00 ⁇ 10 -6 ⁇ cm;
  • the porous matrix has a porosity of 40% to 70%.
  • the bipolar current collector satisfies at least one of the following characteristics:
  • the thickness of the layer formed by the first metal M on the surface of the porous substrate is 0.40 ⁇ m to 13.33 ⁇ m; the thickness of the layer formed by the second metal N on the surface of the porous substrate is 0.40 ⁇ m to 13.33 ⁇ m;
  • the thickness of the bipolar current collector is 5 ⁇ m to 20 ⁇ m;
  • the surface roughness of the bipolar current collector is 0.5 ⁇ m to 2 ⁇ m;
  • the Z-direction electron resistivity of the bipolar current collector is 2.00 ⁇ 10 ⁇ 10 ⁇ cm to 2.00 ⁇ 10 ⁇ 8 ⁇ cm.
  • a second aspect of the present invention provides an electrochemical device comprising at least two electrode assemblies and a bipolar current collector as described in any of the above embodiments, the bipolar current collector being located between the two electrode assemblies .
  • a third aspect of the present invention provides an electronic device comprising the electrochemical device as described in the second aspect above.
  • the present invention provides a bipolar current collector.
  • the bipolar current collector includes a porous substrate, a first metal, and a second metal.
  • the first metal exists on one surface of the porous substrate, and the second metal exists on the other surface. At least one of the first metal or the second metal exists inside the .
  • the porous material has the advantages of anti-oxidation, anti-reduction and ion insulation, and has the advantages of certain mechanical strength; the metal layer of the bipolar current collector has good electronic conduction and ion insulation ability, high mechanical strength, and good thermal stability.
  • both sides of the bipolar current collector due to the roughness of the surfaces on both sides of the bipolar current collector, the interface bonding between the positive and negative electrode diaphragms on both sides and the composite bipolar current collector can be optimized, and the adhesion of the diaphragms can be improved.
  • Both sides of the bipolar current collector of the present invention can be coated with positive active material and negative active material respectively, forming an electrochemical unit with adjacent battery components, and improving the energy density and output voltage of the electrochemical device.
  • FIG. 1 is a schematic diagram of a current collector in an embodiment of the present invention.
  • Figure 2 is a schematic diagram of an electrochemical device in one embodiment of the present invention.
  • FIG. 3 is a schematic diagram of the preparation process of the composite current collector in one embodiment of the present invention.
  • bipolar lithium-ion battery forms a single lithium-ion battery by connecting multiple cells in series, thereby increasing the output voltage of the lithium-ion battery.
  • the current collector used in this lithium-ion battery is a bipolar current collector, in which one side of the bipolar current collector contacts the positive electrode active material, and the other side contacts the negative electrode active material, which requires the current collector to be resistant to oxidation and reduction.
  • bipolar current collectors are usually metal foils such as aluminum/copper composite foils.
  • the existing bipolar lithium-ion batteries usually have the following problems: on the one hand, due to the poor intermetallic bonding of the aluminum/copper composite foil, it is not conducive to the cycling stability of the bipolar lithium-ion battery; on the other hand, the metal Foils are more expensive, thereby increasing the manufacturing cost of bipolar lithium-ion batteries.
  • the existing bipolar current collectors can also include multi-layer metal composite current collectors, which are usually obtained by directly compounding Cu foil and Al foil. The interface bonding is poor, and the thickness of the current collector is difficult to reduce.
  • the present invention provides a bipolar current collector, which includes a porous substrate 1, a first metal M, and a second metal N, and the first metal M exists on one surface of the porous substrate , the second metal N exists on the other surface, and at least one of the first metal M or the second metal N exists in the interior of the porous matrix;
  • the material of the porous matrix includes at least one of carbon materials, polymer materials or third metals A;
  • the porosity of the porous matrix is 20% to 90%, preferably 40% to 70%.
  • the porous matrix material has the advantages of high oxidation resistance, high reduction resistance, high ionic insulation, high mechanical strength, thin thickness and high thermal stability.
  • a metal layer can be prepared on the surface thereof by a PVD (Physical Vapor Deposition, physical vapor deposition) method. Since the porous matrix material has pores, the metal material can penetrate into the porous matrix material and make contact with the metal material deposited on the other side to provide electronic conductivity.
  • PVD Physical Vapor Deposition, physical vapor deposition
  • the surface of the metal layer obtained by the PVD method on both sides of the bipolar current collector has a certain roughness, which can improve the interfacial bonding between the bipolar current collector and the positive and negative active materials coated on the surfaces of the bipolar current collector and the two sides respectively, and improve the bipolar current. Adhesion between the current collector and the positive and negative electrode membranes.
  • the porous matrix may be in the form of a network.
  • the first metal and the second metal can be located on both sides of the porous substrate, or can penetrate into the pores of the porous substrate, and the first metal and the second metal can be in contact with each other after infiltrating.
  • the first metal and the second metal have the advantages of high oxidation resistance, high reduction resistance, high ionic insulation, high mechanical strength, high thermal stability, and thin thickness. Since the first metal and the second metal need to contact the positive electrode active material and the negative electrode active material, respectively, the first metal and the second metal should have compatibility with the positive electrode active material and the negative electrode active material, respectively.
  • the thickness of the bipolar current collector of the present invention is less than or equal to the existing Cu/Al foil current collector material, and can be industrially manufactured on a large scale. Compared with the existing mature stainless steel foil and Ti foil, it has the advantage of low cost; and Compared with the low-cost conductive material/polymer composite, it has the advantages of high electronic conductivity, good rate performance and thin thickness.
  • the carbon material comprises single-wall carbon nanotube film, multi-wall carbon nanotube film, carbon felt, porous carbon film, carbon black, acetylene black, fullerene, conductive graphite or graphite at least one of alkenes.
  • the polymer material includes polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether ether ketone, polyethylene terephthalate Imide, polyamide, polyethylene glycol, polyamideimide, polycarbonate, cyclic polyolefin, polyphenylene sulfide, polyvinyl acetate, polytetrafluoroethylene, polymethylene naphthalene, polyvinylidene Vinyl difluoride, polyethylene naphthalate, polypropylene carbonate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-chlorotrifluoroethylene), silicone, vinylon , at least one of polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyphenylene ether, polyester, polysulfone or derivatives thereof.
  • the matrix of the bipolar current collector is a polymer material
  • the density of the polymer material is lower than that of the commonly used metal current collector material, the weight of the inactive material can be reduced and the mass energy density of the cell can be improved.
  • the third metal, the first metal M, and the second metal N each independently include at least one of Cu, Al, Ni, Ti, Ag, Au, Pt, stainless steel or alloys thereof A sort of.
  • the first metal M and the second metal N may be the same or different, but should be compatible with the positive electrode active material or negative electrode active material coated on the surface thereof, and have corresponding anti-oxidation or anti-reduction properties.
  • the thickness of the layer formed by the first metal M on the surface of the porous substrate is 0.95 ⁇ m to 900 ⁇ m, preferably 0.40 ⁇ m to 13.33 ⁇ m;
  • the thickness of the layer formed on the surface of the porous substrate is 0.95 ⁇ m to 900 ⁇ m, preferably 0.40 ⁇ m to 13.33 ⁇ m.
  • the bipolar current collector has a thickness of 2 ⁇ m to 1000 ⁇ m, preferably 5 ⁇ m to 50 ⁇ m, more preferably 5 to 20 ⁇ m. If the thickness of the bipolar current collector is too large, the proportion of inactive materials in the electrochemical device will increase, and the energy density will be reduced. If the thickness is too small, the mechanical strength is insufficient and it is easy to be damaged.
  • the bipolar current collector has a surface roughness of 0.05 ⁇ m to 10 ⁇ m, preferably 0.2 ⁇ m to 5 ⁇ m, more preferably 0.5 ⁇ m to 2 ⁇ m.
  • the surface roughness of the bipolar current collector is too low, the bonding force of the electrode active material coated on its surface is insufficient; when the surface roughness of the bipolar current collector is too large, it will not continue to improve the bonding effect, Moreover, it may cause fluctuations in the weight distribution of effective substances, increasing the risk of local lithium precipitation.
  • the thickness ratio of the layer of the first metal M formed on the surface of the porous substrate to the layer of the second metal N formed on the surface of the porous substrate is 0.05 to 20, preferably 0.2 to 5.
  • the thickness ratio varies with the material types of M and N selected.
  • the metal layer with low density, low cost and high preparation efficiency is thicker, and vice versa, which can improve ED (Energy Denisty, energy density) and reduce cost.
  • the Z-direction electron resistivity of the bipolar current collector is 2.00 ⁇ 10 ⁇ 10 ⁇ cm to 2.00 ⁇ 10 ⁇ 4 ⁇ cm, preferably 2.00 ⁇ 10 ⁇ 10 ⁇ ⁇ cm to 2.00 ⁇ 10 -6 ⁇ ⁇ cm, more preferably 2.00 ⁇ 10 --10 ⁇ ⁇ cm to 2.00 ⁇ 10 --8 ⁇ ⁇ cm.
  • the Z direction refers to the thickness direction of the bipolar current collector, that is, the direction with the smallest dimension. In the present invention, it is desirable that the Z-direction electron resistivity of the bipolar current collector is small to provide good electron conductivity.
  • the present invention also provides an electrochemical device, comprising at least one bipolar current collector according to the present invention, the bipolar current collector is hermetically connected to an outer package of the electrochemical device, and the bipolar current collector is in a sealed connection with the outer package of the electrochemical device.
  • Two independent sealed chambers are formed on both sides, and each sealed chamber has an electrode assembly and an electrolyte to form an independent electrochemical unit, wherein two sides of the bipolar current collector are respectively coated with opposite polarities. electrode active material.
  • Adjacent electrochemical cells are connected in series through the bipolar electrodes comprising the bipolar current collector of the present invention to form a bipolar lithium ion battery with a higher working voltage.
  • two adjacent electrode assemblies can each lead out a tab, and the polarities of the tabs of the two electrode assemblies are opposite.
  • the bipolar current collector is adjacent to the electrode assembly A
  • the electrode assembly A leads out the negative electrode tab
  • the electrode assembly B leads out the positive electrode tab.
  • the output voltage between the two tabs is the sum of the output voltages of the two electrochemical cells.
  • two adjacent electrode assemblies can each lead out two tabs, for example, when the side of the bipolar current collector adjacent to the electrode assembly A is coated with positive active material, When the adjacent side of assembly B is coated with negative active material, the positive tab of electrode assembly A and the positive tab of electrode assembly B are connected in series, and the negative tab of electrode assembly A and the positive tab of electrode assembly B are output.
  • the output voltage is the sum of the output voltages of the two electrochemical cells.
  • the bipolar current collector can lead out a tab for monitoring the working state of the lithium ion battery.
  • the electrochemical device of the present invention comprises at least one bipolar current collector, the bipolar current collector is hermetically connected to the outer package, and forms independent two sides of the bipolar current collector. Sealed chambers, each sealed chamber contains an electrode assembly and an electrolyte to form an electrochemical unit, wherein one side of the bipolar current collector is coated with electrode active material, and the other side is directly connected to the collector of the electrode assembly.
  • the fluids are in contact and electrically connected.
  • the side of the bipolar current collector close to electrode assembly A is coated with positive active material
  • the side close to electrode assembly B is in direct contact with and electrically connected to the negative electrode current collector of electrode assembly B.
  • electrode assembly A can lead out a negative electrode tab
  • electrode assembly B can lead out a positive electrode tab
  • the two electrochemical cells are connected in series through a bipolar current collector; or electrode assemblies A and B each lead out two poles ear, the positive electrode tab of electrode assembly A is connected in series with the negative electrode tab of electrode assembly B.
  • the two electrochemical cells are connected in series through bipolar current collectors and connected in series through the outside of the tabs.
  • the bipolar current collector can lead out a tab for monitoring the working state of the battery.
  • the electrochemical device of the present invention comprises at least one bipolar current collector, the bipolar current collector is hermetically connected to the outer package, and forms independent two sides of the bipolar current collector. Sealed chambers, each sealed chamber contains an electrode assembly and an electrolyte to form an electrochemical cell, wherein one side of the bipolar current collector is coated with electrode active material, and the other side is in contact with the separator of the electrode assembly. The contacts form electrical isolation.
  • the side of bipolar current collector close to electrode assembly A is coated with positive active material, and the side close to electrode assembly B is in contact with the separator of electrode assembly B to form electrical insulation with electrode assembly B.
  • two tabs are drawn from each of the two electrode assemblies, and one tab is drawn from the bipolar current collector. The tab is connected in parallel with the positive tab of electrode assembly A, and then connected in series with the negative tab of electrode assembly B.
  • the electrochemical device of the present invention comprises at least one bipolar current collector, the bipolar current collector is hermetically connected to the outer package, and forms independent two sides of the bipolar current collector.
  • the sealed chambers each contain an electrode assembly and an electrolyte to form an electrochemical unit, wherein two sides of the bipolar current collector are directly in contact with the diaphragms of the adjacent electrode assemblies and form electrical insulation.
  • two tabs are drawn from each of the two electrode assemblies, and the two electrode assemblies are connected in series through the tabs.
  • an undercoat layer may be included between the bipolar current collector and the electrode active material, and the function of the undercoat layer is to improve the bonding performance between the bipolar current collector and the active material, and The electronic conductivity between the bipolar current collector and the active material can be improved.
  • the primer layer is usually obtained by coating the bipolar current collector with a slurry formed by mixing conductive carbon black, styrene-butadiene rubber and deionized water, and drying on both sides of the bipolar current collector.
  • the primers can be the same or different.
  • the preparation process of the positive electrode active material layer, the negative electrode active material layer, the positive electrode undercoat layer, and the negative electrode undercoat layer will be shown below.
  • FIG. 2 is a schematic diagram of an electrochemical device in an embodiment of the present invention.
  • the bipolar current collector 300 separates the electrochemical device into two electrode assemblies, namely the first electrode assembly 100 and the second electrode assembly.
  • Two-electrode assembly 200 wherein the first electrode assembly 100 sequentially includes a negative electrode 101 , a first negative electrode active material layer 102 , a first separator 103 , a first positive electrode active material layer 104 , and a bipolar electrode from top to bottom in FIG.
  • the second electrode assembly 200 includes a positive electrode 201, a second positive electrode active material layer 202, a second separator 203, a second negative electrode active material layer 204, and a bipolar current collector sequentially from bottom to top in FIG. 2 Another part of 300.
  • the electrochemical device may also be sealed by the sealing member 400 , so that the electrochemical device forms two independent cavity structures, and the two cavities correspond to the first electrode assembly 100 and the second electrode assembly 200 respectively.
  • the present invention also provides an electronic device including the electrochemical device in the above embodiments.
  • the electrode assembly of the present invention is not particularly limited, and any electrode assembly in the prior art can be used as long as the object of the present invention can be achieved, for example, a laminated electrode assembly or a wound electrode assembly can be used.
  • the electrode assembly generally includes a positive pole piece, a negative pole piece and a separator.
  • a negative electrode sheet typically includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode current collector is not particularly limited, and any negative electrode current collector known in the art can be used, such as copper foil, aluminum foil, aluminum alloy foil, and composite current collector.
  • the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material is not particularly limited, and any negative electrode active material known in the art can be used.
  • at least one of artificial graphite, natural graphite, mesocarbon microspheres, soft carbon, hard carbon, silicon, silicon carbon, lithium titanate, and the like may be included.
  • the positive electrode sheet in the present invention is not particularly limited as long as the object of the present invention can be achieved.
  • the positive electrode sheet typically includes a positive electrode current collector and a positive electrode active material.
  • the positive electrode current collector is not particularly limited, and can be any positive electrode current collector known in the art, such as aluminum foil, aluminum alloy foil, or composite current collector.
  • the positive active material is not particularly limited, and can be any positive active material in the prior art, and the active material includes NCM811, NCM622, NCM523, NCM111, NCA, lithium iron phosphate, lithium cobaltate, lithium manganate, and iron manganese phosphate At least one of lithium or lithium titanate.
  • the electrolyte in the present invention is not particularly limited, any electrolyte known in the art can be used, for example, it can be any one of gel state, solid state and liquid state, for example, the liquid electrolyte solution can include lithium salt and non-aqueous solvent.
  • the lithium salt is not particularly limited, and any lithium salt known in the art can be used as long as the object of the present invention can be achieved.
  • the lithium salt may include lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium difluorophosphate (LiPO 2 F 2 ), lithium bistrifluoromethanesulfonimide LiN(CF 3 SO 2 ) 2 ( LiTFSI), lithium bis(fluorosulfonyl)imide Li(N(SO 2 F) 2 ) (LiFSI), lithium bis-oxalate borate LiB(C 2 O 4 ) 2 (LiBOB) or lithium difluorooxalate borate LiBF 2 ( At least one of C 2 O 4 ) (LiDFOB).
  • LiPF 6 can be selected as the lithium salt.
  • the non-aqueous solvent is not particularly limited as long as the object of the present invention can be achieved.
  • the non-aqueous solvent may include at least one of carbonate compounds, carboxylate compounds, ether compounds, nitrile compounds, or other organic solvents.
  • the carbonate compound may include diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethylene propylene carbonate Ester (EPC), Ethyl Methyl Carbonate (MEC), Ethylene Carbonate (EC), Propylene Carbonate (PC), Butylene Carbonate (BC), Vinyl Ethylene Carbonate (VEC), Fluorocarbonate Ethyl carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-carbonate Tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1-fluorocarbonate , At least one of 1,2-trifluoro-2-methylethylene or trifluoromethylethylene carbonate,
  • the separator in the present invention is not particularly limited, and for example, the separator includes a polymer, an inorganic substance, or the like formed of a material that is stable to the electrolyte solution of the present invention.
  • the separator should generally be ionically conductive and electronically insulating.
  • the separator may include a substrate layer and a surface treatment layer.
  • the substrate layer can be a non-woven fabric, film or composite film with a porous structure, and the material of the substrate layer can be selected from at least one of polyethylene, polypropylene, polyethylene terephthalate and polyimide. kind.
  • polypropylene porous membranes, polyethylene porous membranes, polypropylene non-woven fabrics, polyethylene non-woven fabrics, or polypropylene-polyethylene-polypropylene porous composite membranes may be used.
  • at least one surface of the substrate layer is provided with a surface treatment layer, and the surface treatment layer can be a polymer layer or an inorganic layer, or a layer formed by mixing a polymer and an inorganic substance.
  • the inorganic layer includes inorganic particles and a binder
  • the inorganic particles are not particularly limited, and can be selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium dioxide, tin oxide, ceria, nickel oxide, for example , at least one of zinc oxide, calcium oxide, zirconium oxide, yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide and barium sulfate.
  • the binder is not particularly limited, for example, it can be selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyethylene One or a combination of rolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.
  • the polymer layer contains a polymer, and the material of the polymer includes polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinyl ether, polyvinylidene fluoride or poly( At least one of vinylidene fluoride-hexafluoropropylene).
  • the present invention also provides a preparation method of the composite bipolar current collector in any of the above embodiments, comprising the following steps:
  • a layer of polymer material particle coating 2 is prepared on the surface of the stainless steel substrate 3 by electrostatic spraying;
  • the bipolar current collector according to the present invention can be prepared by any other method, and is not limited to the method exemplified above.
  • the PVD method can be performed by CVD (Chemical Vapor Deposition, chemical vapor deposition) method, electroplating and other methods.
  • PVD Physical Vapor Deposition, Physical Vapor Deposition: refers to the use of low-voltage, high-current arc discharge technology under vacuum conditions, using gas discharge to evaporate the target and ionize the evaporated material and gas. Acceleration causes the vaporized substances and their reaction products to be deposited on the workpiece. Compared with the CVD process, the PVD process has a lower processing temperature, and the internal stress state of the film is compressive stress. The PVD process has no adverse impact on the environment, which is in line with the development direction of modern green manufacturing.
  • the electrochemical device is realized by taking a lithium ion battery as an example of the electrochemical device, but the electrochemical device is not limited to the lithium ion battery.
  • PVDF polyvinylidene fluoride
  • the A side of the PI (polyimide) porous film with a thickness of 140 ⁇ m is attached to the surface of the PVDF coating, and the porosity of the polyimide porous film is 60%;
  • the superheated pressing roller is 200 °C to make the metal Al and Cu on both sides of the A and B surfaces closely adhere to it, and the total thickness of the composite current collector is reduced to 100 ⁇ m, of which the thickness of the Al layer is about 66.66 ⁇ m, and the thickness of the Cu layer is about 66.66 ⁇ m. about 33.33 ⁇ m;
  • the negative electrode active material graphite, Super P (conductive carbon black), and SBR (styrene-butadiene rubber) were mixed in a mass ratio of 96:1.5:2.5, and then deionized water was added as a solvent to prepare a slurry with a solid content of 70%. and stir well.
  • the slurry was uniformly coated on one side of the bipolar current collector, and dried at 110° C. to obtain a negative electrode active material layer, and the thickness of the negative electrode active material layer was 130 ⁇ m.
  • the positive active material LiCoO 2 lithium cobalt oxide
  • conductive carbon black conductive carbon black
  • PVDF polyvinyl ether
  • NMP N-methylpyrrolidone
  • the slurry was uniformly coated on the other side of the bipolar current collector, and dried at 90° C. to obtain a positive electrode active material layer, wherein the thickness of the positive electrode active material layer was 110 ⁇ m.
  • a bipolar pole piece is obtained, and the pole piece is cut into a size of 41mm ⁇ 61mm for use.
  • the negative electrode active material graphite, conductive carbon black, and styrene-butadiene rubber were mixed according to a mass ratio of 96:1.5:2.5, deionized water was added as a solvent, and a slurry with a solid content of 70% was prepared and stirred evenly.
  • the slurry was uniformly coated on one surface of a copper foil with a thickness of 10 ⁇ m, and dried at 110 ° C to obtain a negative electrode pole piece with a single-sided coating of a negative electrode active material layer with a coating thickness of 150 ⁇ m layer thickness, and then in the The above coating steps were repeated on the other surface of the negative pole piece. After the coating is completed, the pole piece is cut into a size of 41mm ⁇ 61mm, and the tabs are welded for later use.
  • the positive active material LiCoO 2 , conductive carbon black, and PVDF were mixed in a mass ratio of 97.5:1.0:1.5, and NMP was added as a solvent to prepare a slurry with a solid content of 75%, and the mixture was uniformly stirred.
  • the slurry was uniformly coated on one surface of an aluminum foil with a thickness of 12 ⁇ m, and dried at 90° C. to obtain a single-sided positive electrode sheet with a coating thickness of 100 ⁇ m coated with a positive electrode active material layer.
  • the above steps are then repeated on the other surface of the positive pole piece. After the coating is completed, the pole piece is cut into a size of 38mm ⁇ 58mm and the tabs are welded for use.
  • organic solvents EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DEC diethyl carbonate
  • LiPF 6 lithium hexafluorophosphate
  • a PE (polyethylene) film with a thickness of 15 ⁇ m is used as the separator, a positive electrode is placed on both sides of the negative electrode, and a separator is placed between the positive electrode and the negative electrode to form a stack, and then the entire stack is placed. The four corners of the structure are fixed, and the electrode assembly A is obtained.
  • a PE film with a thickness of 15 ⁇ m is used as the separator, a negative electrode is placed on both sides of the positive electrode, and a separator is placed between the positive electrode and the negative electrode to form a stack, and then the four The corners are fixed, and the electrode assembly B is obtained.
  • the above-mentioned assembled semi-finished product is placed in another assembly fixture, the positive side of the bipolar pole piece is facing up, and the electrode assembly B is placed on the bipolar current collector, wherein the negative electrode of the electrode assembly B and the positive electrode of the bipolar pole piece are active.
  • the material layer corresponds, and then another aluminum-plastic film with a thickness of 90 ⁇ m formed by punching is covered on the electrode assembly B with the pit face down, and then the two aluminum-plastic films are heat-sealed by hot pressing to make the electrode assembly A. and electrode assembly B are separated by bipolar pole pieces to obtain bipolar electrode assembly.
  • the bipolar electrode assembly has two independent cavities, wherein the electrode assembly A corresponds to the first cavity, and the electrode assembly B corresponds to the second cavity.
  • the electrolyte is injected into the two cavities of the bipolar electrode assembly respectively and then packaged. Each electrode assembly leads out a tab, and the electrode assembly in the first cavity and the electrode assembly in the second cavity are passed through the bipolar electrode assembly.
  • the current collector is connected in series to obtain a bipolar lithium ion battery, and there is no ion exchange between the two cavities of the bipolar lithium ion battery.
  • PVDF polyvinylidene fluoride
  • the superheated pressing roller is 200 °C to make the metal Al and Cu on both sides of the A and B surfaces closely adhere to it, and the total thickness of the composite current collector is reduced to 20 ⁇ m, wherein the thickness of the Al layer is about 13.33 ⁇ m, and the thickness of the Cu layer is about 13.33 ⁇ m. about 6.67 ⁇ m;
  • Ti was prepared on the B side; Ti was prepared on the A side, except that the porosity of the PI porous film was 20%. The rest are the same as in Example 5.
  • the porosity of the PI porous film is 40%, and the adjusted Z-direction electron resistivity is 2.00 ⁇ 10 -7 ⁇ cm, the rest is the same as that of Example 6.
  • the PI porous film was replaced with a Ni porous matrix, and the porosity of the Ni porous matrix was 90%; 6) On the B side of the Ni porous matrix and the PVDF coating composite film, through Ag with a thickness of 14.00 ⁇ m was prepared by PVD method;
  • Example 8 Ag with a thickness of 14.00 ⁇ m was prepared by PVD method on the A side of the Ni porous substrate. Others are the same as in Example 2.
  • Ni was prepared on the A side. The rest are the same as in Example 6.
  • Ni was prepared on the B side. The rest are the same as in Example 6.
  • PVDF polyvinylidene fluoride
  • the A side of the PI (polyimide) porous film with a thickness of 1400 ⁇ m is attached to the surface of the PVDF coating, and the porosity of the polyimide porous film is 60%;
  • the superheated pressing roller is 200 °C to make the metal Al and Cu on both sides of the A and B surfaces closely adhere to it, and the total thickness of the composite current collector is reduced to 1000 ⁇ m, of which the thickness of the Al layer is about 200.00 ⁇ m, and the thickness of the Cu layer is about 200.00 ⁇ m. About 800.00 ⁇ m;
  • PVDF polyvinylidene fluoride
  • the superheated pressing roller is 200°C to make the metal Al and Cu on both sides of the A and B surfaces closely adhere to it, and the total thickness of the composite current collector is reduced to 10 ⁇ m, wherein the thickness of the Al layer is about 2.00 ⁇ m, and the thickness of the Cu layer is about 2.00 ⁇ m. about 8.00 ⁇ m;
  • PVDF polyvinylidene fluoride
  • the superheated pressing roller is 200 °C to make the metal Al and Cu on both sides of the A and B surfaces closely adhere to it, and the total thickness of the composite current collector is reduced to 2 ⁇ m, wherein the thickness of the Al layer is about 0.40 ⁇ m, and the thickness of the Cu layer is about 0.40 ⁇ m. about 1.60 ⁇ m;
  • a negative electrode undercoat layer and a positive electrode undercoat layer are added to the bipolar pole piece.
  • the specific data are shown in Table 1, and the rest are the same as in Example 19.
  • the conductive carbon black and styrene-butadiene rubber were mixed according to a mass ratio of 95:5, deionized water was added as a solvent, and the slurry was prepared into a slurry with a solid content of 80%, and stirred evenly.
  • the slurry was uniformly coated on the surface of the composite bipolar current collector A, and dried at 110° C. to obtain a negative electrode primer with a thickness of 5 ⁇ m.
  • the negative electrode active material graphite, conductive carbon black, and styrene-butadiene rubber were mixed according to a mass ratio of 96:1.5:2.5, deionized water was added as a solvent, and a slurry with a solid content of 70% was prepared and stirred evenly.
  • the slurry was uniformly coated on the negative electrode primer layer, and dried at 110° C. to obtain a negative electrode pole piece with a thickness of 120 ⁇ m.
  • the conductive carbon black and styrene-butadiene rubber are mixed according to a mass ratio of 97:3, deionized water is added as a solvent, and the slurry with a solid content of 85% is prepared and stirred evenly.
  • the slurry was uniformly coated on the B surface of the composite bipolar current collector, and dried at 110° C. to obtain a positive electrode primer layer with a thickness of 3 ⁇ m.
  • the positive active material LiCoO 2 , conductive carbon black, and PVDF were mixed in a mass ratio of 97.5:1.0:1.5, and NMP was added as a solvent to prepare a slurry with a solid content of 75%, and the mixture was uniformly stirred.
  • the slurry was uniformly coated on the positive electrode primer layer, and dried at 90° C. to obtain a positive electrode pole piece with a thickness of 100 ⁇ m.
  • the double-sided coated negative pole piece, the separator, and the double-sided coated positive pole piece are stacked in sequence to form a laminated sheet, and then the entire laminated sheet is wound, and the negative pole piece is placed on the outermost side.
  • the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • the double-sided coated negative pole piece, the separator, and the double-sided coated positive pole piece are stacked in sequence to form a laminated sheet, and then the whole laminated sheet is wound, and the positive pole piece is placed at the outermost side.
  • the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • the thickness of the Cu/Al composite current collector is 20 ⁇ m.
  • Example 2 The rest is the same as in Example 1, except that the bipolar current collector is selected as a stainless steel foil current collector.
  • the thickness of the stainless steel foil current collector is 20 ⁇ m.
  • the zero-dimensional conductive material is dotted carbon black particles
  • the polymer substrate is PET substrate.
  • the thickness is about 50 ⁇ m.
  • bipolar current collector is obtained by compounding a one-dimensional structure conductive material and a polymer substrate, the rest is the same as that of Example 1.
  • the one-dimensional conductive material is MWCNT
  • the polymer substrate is PET substrate
  • the MWCNT is uniformly and non-orientedly dispersed in the three-dimensional distribution matrix
  • the thickness of the bipolar current collector is about 50 ⁇ m.
  • bipolar current collector is obtained by compounding a two-dimensional structure conductive material and a polymer substrate, the rest is the same as that of Example 1.
  • the two-dimensional conductive material is graphene
  • the polymer substrate is PET substrate
  • the graphene is uniformly dispersed in the three-dimensional distribution matrix without orientation
  • the thickness of the bipolar current collector is about 50 ⁇ m.
  • a very sharp stylus is placed vertically on the surface to be tested for lateral movement. Since the working surface is rough and uneven, the stylus will move vertically up and down with the contour shape of the tested surface. This tiny displacement is converted into an electrical signal through a circuit and amplified and processed to obtain the surface roughness parameter value of the workpiece; the surface contour pattern can also be drawn through a recorder, and then data processing is performed to obtain the surface roughness. parameter value.
  • the specific test method is: the difference between the average value of the 5 largest contour peak heights and the average value of the 5 largest contour valley depths within the sampling length (10cm).
  • the suitable surface roughness Rz measured by this method ranges from 0.02 ⁇ m to 160 ⁇ m.
  • the thickness of the bipolar current collector layer is denoted by H.
  • the composite bipolar current collector is clamped on both sides with fixed-area splints, and the resistance value is measured, then divided by the thickness and multiplied by the plate area.
  • the adhesive force with the positive pole piece is F +
  • the adhesive force with the negative pole piece is F - .
  • the lithium-ion battery was allowed to stand at room temperature for 30 minutes, charged at a constant current rate of 0.05C to 8.8V (rated voltage), and then discharged to 6.0V at a rate of 0.05C, repeating the above charge/discharge Step 3 cycles to complete the formation of the electrochemical device to be tested. After completing the formation of the electrochemical device, charge the electrochemical device to a voltage of 8.8V with a constant current at a charging rate of 0.1C, and then discharge the electrochemical device to 6.0V at a discharge rate of 0.1C, record its discharge capacity, and then calculate its 0.1C discharge rate.
  • Energy Density :
  • Mass energy density (Wh/kg) discharge energy (Wh) / lithium-ion battery weight (kg)
  • the test temperature is 25°C, charge with 0.5C constant current to 8.8V, constant voltage charge to 0.025C, and discharge at 0.5C to 6.0V after standing for 5 minutes, the capacity obtained in this step is the initial capacity, and then 0.5C After 50 cycles of charging/discharging at 0.5C, the ratio of the capacity of the lithium-ion battery to the initial capacity was calculated.
  • the lithium ion battery in the embodiment of the present invention has The energy density, the ratio of the discharge capacity after 50 cycles to the first discharge capacity, and the adhesion between the diaphragm and the bipolar current collector all increased.
  • the energy density of the lithium ion batteries given in the examples of the present invention basically does not change.
  • the adhesive force between the diaphragm and the bipolar current collector in the embodiment of the present invention increases.
  • the performance of the lithium ion battery of the embodiment of the present invention is better than that of the comparative example.

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Abstract

本发明提供一种双极性集流体、电化学装置及电子装置，双极性集流体包括多孔基体、第一金属、第二金属，多孔基体的一个表面存在第一金属，另一个表面存在第二金属，多孔基体的内部存在第一金属或第二金属中的至少一种。由于多孔基体具有抗氧化性、抗还原性、离子绝缘性，具有一定的机械强度的优点；双极性集流体的金属层具有良好的电子传导及离子绝缘能力，机械强度高、热稳定性好的优点，并且由于双极性集流体两侧表面具有一定粗糙度，可优化两侧正负极膜片与复合双极性集流体的界面结合，提升膜片粘结力。

Description

一种双极性集流体、电化学装置及电子装置 技术领域
本发明涉及电池领域，具体涉及一种双极性集流体、包含该双极性集流体的电化学装置及电子装置。
背景技术
锂离子电池由于具有体积和质量能量密度大、循环寿命长、标称电压高、自放电率低、体积小、重量轻等许多优点，在消费电子领域广泛的应用。随着近年来电动汽车和可移动电子设备的高速发展，人们对电池的能量密度、安全性能、循环性能等相关需求越来越高，需要研发综合性能全面提升的新型锂离子电池。
为了提高锂离子电池的输出电压，目前已经采取了锂离子电池串联的方案。在该方案中，将两个电极组件放置在一个密封腔室中，两个电极组件分别引出极耳，通过极耳的串联连接，从而提高输出电压。另一种方案是在两个电极组件之间设置隔板，两个电极组件分别引出极耳，通过极耳串联连接，从而提高输出电压。
发明内容
本发明的目的在于提供一种双极性集流体、电化学装置及电子装置，以提高电化学装置的输出电压。
本发明的第一方面提供一种双极性集流体，其包括多孔基体、第一金属M、第二金属N，所述多孔基体的一个表面存在第一金属M，另一个表面存在第二金属N，多孔基体的内部存在第一金属M或第二金属N中的至少一种；
所述多孔基体的材料包括碳材料、高分子材料或第三金属中的至少一种；
所述多孔基体的孔隙率为20％至90％。
在本发明的一种实施方案中，所述碳材料包括单壁碳纳米管膜、多壁碳纳米管膜、碳毡、多孔碳膜、炭黑、乙炔黑、富勒烯、导电石墨或石墨烯中的至少一种。
在本发明的一种实施方案中，所述高分子材料包括聚对苯二甲酸亚乙酯、聚对苯二甲酸丁二醇酯、聚萘二甲酸乙二醇酯、聚醚醚酮、聚酰亚胺、聚酰胺、聚乙二醇、聚酰胺酰亚胺、聚碳酸酯、环状聚烯烃、聚苯硫醚、聚乙酸乙烯酯、聚四氟乙烯，聚亚甲基萘、聚偏二氟乙烯，聚萘二甲酸亚乙酯、聚碳酸亚丙酯、聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)、有机硅、维尼纶、聚丙烯、聚乙烯、聚氯乙烯、聚苯乙烯、聚醚 腈、聚氨酯、聚苯醚、聚酯、聚砜或其衍生物中的至少一种。
在本发明的一种实施方案中，用于所述多孔基体的第三金属、第一金属M、第二金属N各自独立地包括Cu、Al、Ni、Ti、Ag、Au、Pt、不锈钢或其合金中的至少一种。
在本发明的一种实施方案中，第一金属M在所述多孔基体表面形成的层的厚度为0.95μm至900μm；第二金属N在所述多孔基体表面形成的层的厚度为0.95μm至900μm。
在本发明的一种实施方案中，所述双极性集流体的厚度为2μm至1000μm。
在本发明的一种实施方案中，所述双极性集流体的表面粗糙度为0.05μm至10μm。
在本发明的一种实施方案中，第一金属M在所述多孔基体表面形成的层与第二金属N在所述多孔基体表面形成的层的厚度比为0.05至20。
在本发明的一种实施方案中，所述双极性集流体的Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -4Ω·cm。
在本发明的一种实施方案中，所述双极性集流体满足以下特征中的至少一者：
(a)所述双极性集流体的厚度为5μm至50μm；
(b)所述双极性集流体的表面粗糙度为0.2μm至5μm；
(c)第一金属M在所述多孔基体表面形成的层与第二金属N在所述多孔基体表面形成的层的厚度比为0.2至5；
(d)所述双极性集流体Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -6Ω·cm；
(e)所述多孔基体的孔隙率为40％至70％。
在本发明的一种实施方案中，所述双极性集流体满足以下特征中的至少一者：
(a)第一金属M在所述多孔基体表面形成的层的厚度为0.40μm至13.33μm；第二金属N在所述多孔基体表面形成的层的厚度为0.40μm至13.33μm；
(b)所述双极性集流体的厚度为5μm至20μm；
(c)所述双极性集流体的表面粗糙度为0.5μm至2μm；
(d)所述双极性集流体Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -8Ω·cm。
本发明的第二方面提供了一种电化学装置，包括至少两个电极组件以及上述任一实施方案中所述的双极性集流体，所述双极性集流体位于两个电极组件之间。
本发明的第三方面提供了一种电子装置，所述电子装置包括如上述第二方面所述的电化学装置。
本发明提供一种双极性集流体，双极性集流体包括多孔基体、第一金属、第二金属， 所述多孔基体的一个表面存在第一金属，另一个表面存在第二金属，多孔基体的内部存在第一金属或第二金属中的至少一种。由于多孔材料具有抗氧化性、抗还原性、离子绝缘性，具有一定的机械强度的优点；双极性集流体的金属层具有良好的电子传导及离子绝缘能力、机械强度高、热稳定性好的优点，并且由于双极性集流体两侧表面具有一定粗糙度，可优化两侧正极膜片和负极膜片与复合双极性集流体的界面结合，提升膜片粘结力。本发明的双极性集流体两侧可以分别涂覆正极活性材料和负极活性材料，与相邻的电池组件形成电化学单元，提高电化学装置的能量密度和输出电压。
附图说明
为了更清楚地说明本发明和现有技术的技术方案，下面对实施例和现有技术中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的技术方案。
图1为本发明一种实施方案中的集流体的示意图；
图2为本发明一种实施方案中的电化学装置的示意图；
图3为本发明一种实施方案中复合集流体的制备流程示意图。
具体实施方式
为使本发明的目的、技术方案、及优点更加清楚明白，以下参照附图和实施例，对本发明进一步详细说明。显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
双极性锂离子电池作为一种新型的锂离子电池，以多个电芯内串联的方式组成单个的锂离子电池，从而提高锂离子电池的输出电压。这种锂离子电池所使用的集流体为双极性集流体，其中，双极性集流体的一侧接触正极活性物质，另一侧接触负极活性物质，这就要求集流体耐氧化、耐还原，因此双极性集流体通常为铝/铜复合箔等金属箔。但是，现有的双极性锂离子电池通常存在如下问题：一方面，由于铝/铜复合箔金属间界面结合差，因而不利于双极性锂离子电池的循环稳定性；另一方面，金属箔价格较昂贵，因而增加了双极性锂离子电池的制造成本。
另外，现有的双极性集流体还可以包括多层金属复合集流体，这种集流体通常是将Cu箔和Al箔直接复合得到，虽然具有一定的抗氧化抗还原能力，但是存在金属间界面结合 差，集流体厚度难以减薄等问题。
有鉴于此，如图1所示，本发明提供了一种双极性集流体，其包括多孔基体1、第一金属M、第二金属N，所述多孔基体的一个表面存在第一金属M，另一个表面存在第二金属N，多孔基体的内部存在第一金属M或第二金属N中的至少一种；所述多孔基体的材料包括碳材料、高分子材料或第三金属中的至少一种；所述多孔基体的孔隙率为20％至90％，优选为40％至70％。
多孔基体材料具有抗氧化性高、抗还原性高、离子绝缘性高、机械强度高、厚度薄、热稳定性高的优点。当热稳定性大于300℃时，可以通过PVD(Physical Vapor Deposition，物理气相沉积)方法在其表面制备金属层。由于多孔基体材料具有孔隙，金属材料可以渗透到多孔基体材料中，并与另一侧沉积的金属材料相互接触，提供电子传导性。双极性集流体两侧通过PVD方法得到金属层表面具有一定粗糙度，可以提高双极性集流体与其两侧表面分别涂覆的正极活性材料和负极活性材料的界面结合性，提高双极性集流体与正负极膜片的粘结力。本发明中，所述多孔基体可以为网络状。
本发明中，第一金属和第二金属可以位于多孔基体的两侧表面，也可以渗入多孔基体的孔隙中，并且，第一金属和第二金属在渗入后可以相互接触。
上述第一金属、第二金属具有抗氧化性高、抗还原性高、离子绝缘性高、机械强度高、热稳定性高、厚度薄的优点。由于第一金属、第二金属要分别接触正极活性材料和负极活性材料，因此第一金属、第二金属应分别具有与正极活性材料和负极活性材料的可兼容性。
本发明的双极性集流体厚度小于或等于现有Cu/Al箔集流体材料，并且可以大规模工业化制造，与现有的成熟的不锈钢箔和Ti箔相比，具有成本低的优点；与成本较低的导电材料/高分子复合物相比，具有电子导电率高、倍率性能好、厚度薄的优点。
在本发明的一种实施方案中，所述碳材料包括单壁碳纳米管膜、多壁碳纳米管膜、碳毡、多孔碳膜、炭黑、乙炔黑、富勒烯、导电石墨或石墨烯中的至少一种。
在本发明的一种实施方案中，所述高分子材料包括聚对苯二甲酸亚乙酯、聚对苯二甲酸丁二醇酯、聚萘二甲酸乙二醇酯、聚醚醚酮、聚酰亚胺、聚酰胺、聚乙二醇、聚酰胺酰亚胺、聚碳酸酯、环状聚烯烃、聚苯硫醚、聚乙酸乙烯酯、聚四氟乙烯，聚亚甲基萘、聚偏二氟乙烯，聚萘二甲酸亚乙酯、聚碳酸亚丙酯、聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)、有机硅、维尼纶、聚丙烯、聚乙烯、聚氯乙烯、聚苯乙烯、聚醚腈、聚氨酯、聚苯醚、聚酯、聚砜或其衍生物中的至少一种。
当双极性集流体的基体为高分子材料时，由于高分子材料的密度小于常用的金属集流体材料的密度，可以降低非活性物质的重量，提高电芯的质量能量密度。
在本发明的一种实施方案中，所述第三金属、第一金属M、第二金属N各自独立地包括Cu、Al、Ni、Ti、Ag、Au、Pt、不锈钢或其合金中的至少一种。
所述第一金属M和所述第二金属N可以相同或不同，但是应当和与其表面涂覆的正极活性材料或负极活性材料相兼容，具有相应的抗氧化或抗还原性能。
在本发明的一种实施方案中，所述第一金属M在所述多孔基体表面形成的层的厚度为0.95μm至900μm，优选为0.40μm至13.33μm；所述第二金属N在所述多孔基体表面形成的层的厚度为0.95μm至900μm，优选为0.40μm至13.33μm。
在本发明的一种实施方案中，所述双极性集流体的厚度为2μm至1000μm，优选为5μm至50μm，更优选为5至20μm。双极性集流体的厚度过大，则导致电化学装置中的非活性材料比例增大，降低能量密度。厚度过小，则机械强度不足，容易损坏。
在本发明的一种实施方案中，所述双极性集流体的表面粗糙度为0.05μm至10μm，优选为0.2μm至5μm，更优选为0.5μm至2μm。当双极性集流体的表面粗糙度过低时，与其表面涂覆的电极活性材料粘结力不足；当双极性集流体的表面粗糙度过大时，不但不会继续改善粘结效果，而且可能导致有效物质重量分布出现波动，增大局部析锂风险。
在本发明的一种实施方案中，所述第一金属M在所述多孔基体表面形成的层与第二金属N在所述多孔基体表面形成的层的厚度比为0.05至20，优选为0.2至5。该厚度比随着所选择的M和N的材料种类而变化。一般来说，密度低、成本低、制备效率高的金属层较厚，反之则较薄，从而可以提高ED(Energy Denisty，能量密度)并降低成本。
在本发明的一种实施方案中，所述双极性集流体的Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -4Ω·cm，优选为2.00×10 -10Ω·cm至2.00×10 -6Ω·cm，更优选为2.00×10 --10Ω·cm至2.00×10 --8Ω·cm。所述Z方向是指所述双极性集流体的厚度方向，即尺度最小的方向。在本发明中，希望双极性集流体的Z方向电子电阻率较小，以提供良好的电子传导性。
本发明还提供了一种电化学装置，其包括至少一个根据本发明的双极性集流体，所述双极性集流体与电化学装置的外包装密封连接，在所述双极性集流体两侧形成两个独立的密封腔室，每个密封腔室中具有一个电极组件和电解液，形成独立的电化学单元，其中，所述双极性集流体两侧分别涂覆相反极性的电极活性材料。相邻的电化学单元之间通过包 含本发明双极性集流体的双极性电极内串联，形成双极性锂离子电池，具有更高的工作电压。
在本发明的一种实施方案中，相邻的两个电极组件可以各引出一个极耳，这两个电极组件的极耳极性相反，例如，当双极性集流体与电极组件A相邻的一侧涂覆正极活性材料、与电极组件B相邻的一侧涂覆负极活性材料时，电极组件A引出负极极耳，电极组件B引出正极极耳。此时，两个极耳之间的输出电压为两个电化学单元输出电压之和。
在本发明的一种实施方案中，相邻的两个电极组件可以各引出两个极耳，例如，当双极性集流体与电极组件A相邻的一侧涂覆正极活性材料、与电极组件B相邻的一侧涂覆负极活性材料时，电极组件A的正极极耳与电极组件B的正极极耳串联在一起，电极组件A的负极极耳与电极组件B的正极极耳为输出极耳，输出电压为两个电化学单元输出电压之和。此时，两个相邻的电化学单元之间同时存在通过双极性集流体的内串联和通过极耳的外串联。
在本发明的一种实施方案中，双极性集流体可以引出一个极耳，用于监控锂离子电池的工作状态。
在本发明的一种实施方案中，本发明的电化学装置包含至少一个双极性集流体，所述双极性集流体与外包装密封连接，在双极性集流体两侧形成各自独立的密封腔室，每个密封腔室中包含一个电极组件和电解液，形成一个电化学单元，其中，所述双极性集流体一侧涂覆电极活性材料，另一侧直接与电极组件的集流体相接触并且电连接。例如，双极性集流体靠近电极组件A的一侧涂覆正极活性材料，靠近电极组件B的一侧直接与电极组件B的负极集流体直接接触并且电连接。此时，电极组件A可以引出一个负极极耳，电极组件B可以引出一个正极极耳，两个电化学单元之间通过双极性集流体内串联；或者电极组件A和B各引出两个极耳，电极组件A的正极极耳与电极组件B的负极极耳串联，此时，两个电化学单元之间通过双极性集流体内串联并且通过极耳外部串联。此外，双极性集流体可以引出一个极耳，用于监控电池工作状态。
在本发明的一种实施方案中，本发明的电化学装置包含至少一个双极性集流体，所述双极性集流体与外包装密封连接，在双极性集流体两侧形成各自独立的密封腔室，每个密封腔室中包含一个电极组件和电解液，形成一个电化学单元，其中，所述双极性集流体一侧涂覆电极活性材料，另一侧与电极组件的隔膜相接触形成电绝缘。例如，双极性集流体靠近电极组件A的一侧涂覆正极活性材料，靠近电极组件B的一侧与电极组件B的隔膜 接触形成与电极组件B的电绝缘。此时，两个电极组件各引出两个极耳，双极性集流体引出一个极耳，该极耳与电极组件A的正极极耳并联，然后与电极组件B的负极极耳串联。
在本发明的一种实施方案中，本发明的电化学装置包含至少一个双极性集流体，所述双极性集流体与外包装密封连接，在双极性集流体两侧形成各自独立的密封腔室，每个密封腔室中包含一个电极组件和电解液，形成一个电化学单元，其中，所述双极性集流体两侧直接与相邻的电极组件的隔膜接触并形成电绝缘。此时，两个电极组件各引出两个极耳，两个电极组件之间通过极耳串联连接。
在本发明的一种实施方案中，双极性集流体与电极活性材料之间可以包含底涂层，底涂层的作用是改善双极性集流体与活性物质之间的粘结性能，并能够提高双极性集流体与活性物质之间的电子传导能力。所述底涂层通常是将导电炭黑、丁苯橡胶和去离子水混合后形成的浆料涂覆于双极性集流体上，经烘干后得到的，并且，双极性集流体两面的底涂层可以相同，也可以不同。正极活性物质层、负极活性物质层、正极底涂层、以及负极底涂层的制备过程将在下文中示出。
图2为本发明一种实施方案中的电化学装置的示意图，如图2所示，双极性集流体300将该电化学装置分隔为两个电极组件，分别为第一电极组件100和第二电极组件200，其中，第一电极组件100在图2中由上至下依次包括负极101、第一负极活性材料层102、第一隔膜103、第一正极活性材料层104、以及双极性集流体300的一部分；第二电极组件200在图2中由下至上依次包括正极201、第二正极活性材料层202、第二隔膜203、第二负极活性材料层204、以及双极性集流体300的另一部分。并且，电化学装置还可以通过密封件400密封，使该电化学装置形成两个独立的腔体结构，两个腔体分别对应第一电极组件100和第二电极组件200。
本发明还提供了一种电子装置，包括上述实施方案中的电化学装置。
本发明的电极组件没有特别限制，可以使用现有技术的任何电极组件，只要可以实现本发明目的即可，例如可以使用叠片型电极组件或卷绕型电极组件。电极组件一般包括正极极片、负极极片及隔膜。
本发明中的负极极片没有特别限制，只要能够实现本发明目的即可。例如，负极极片通常包含负极集流体和负极活性材料层。其中，负极集流体没有特别限制，可以使用本领域公知的任何负极集流体，例如铜箔、铝箔、铝合金箔以及复合集流体等。负极活性材料层包括负极活性材料，负极活性材料没有特别限制，可以使用本领域公知的任何负极活性 材料。例如，可以包括人造石墨、天然石墨、中间相碳微球、软碳、硬碳、硅、硅碳、钛酸锂等中的至少一种。
本发明中的正极极片没有特别限制，只要能够实现本发明目的即可。例如，所述正极极片通常包含正极集流体和正极活性材料。其中，所述正极集流体没有特别限制，可以为本领域公知的任何正极集流体，例如铝箔、铝合金箔或复合集流体等。所述正极活性材料没有特别限制，可以为现有技术的任何正极活性材料，所述活性物质包括NCM811、NCM622、NCM523、NCM111、NCA、磷酸铁锂、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂中的至少一种。
本发明中的电解液没有特别限制，可以使用本领域公知的任何电解液，例如可以是凝胶态、固态和液态中的任一种，例如，液态电解液可以包括锂盐和非水溶剂。
锂盐没有特别限制，可以使用本领域公知的任何锂盐，只要能实现本发明的目的即可。例如，锂盐可以包括六氟磷酸锂(LiPF 6)、四氟硼酸锂(LiBF 4)、二氟磷酸锂(LiPO 2F 2)、双三氟甲烷磺酰亚胺锂LiN(CF 3SO 2) 2(LiTFSI)、双(氟磺酰)亚胺锂Li(N(SO 2F) 2)(LiFSI)、双草酸硼酸锂LiB(C 2O 4) 2(LiBOB)或二氟草酸硼酸锂LiBF 2(C 2O 4)(LiDFOB)中的至少一种。例如，锂盐可选用LiPF 6。
非水溶剂没有特别限定，只要能实现本发明的目的即可。例如，非水溶剂可以包括碳酸酯化合物、羧酸酯化合物、醚化合物、腈化合物或其它有机溶剂中的至少一种。
例如，碳酸酯化合物可以包括碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)、碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)、碳酸氟代亚乙酯(FEC)、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯或碳酸三氟甲基亚乙酯中的至少一种。
本发明中的隔膜没有特别限制，例如，隔膜包括由对本发明的电解液稳定的材料形成的聚合物或无机物等。隔膜一般应当具有离子传导性和电子绝缘性。
例如隔膜可包括基材层和表面处理层。基材层可以为具有多孔结构的无纺布、膜或复合膜，基材层的材料可以选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。任选地，可以使用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯-聚丙烯多孔复合膜。任选地，基材层的至少一个表面上设置有表面处理 层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。
例如，无机物层包括无机颗粒和粘结剂，所述无机颗粒没有特别限制，例如可以选自氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙和硫酸钡中的至少一种。所述粘结剂没有特别限制，例如可以选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的一种或几种的组合。聚合物层中包含聚合物，聚合物的材料包括聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯醚、聚偏氟乙烯或聚(偏氟乙烯-六氟丙烯)中的至少一种。
如图3所示，本发明还提供了一种上述任一实施方案中所述复合双极性集流体的制备方法，包括以下步骤：
1)在不锈钢基板3表面利用静电喷涂方法制备一层高分子材料颗粒涂层2；
2)高温热处理使高分子材料颗粒涂层2达到软化温度；
3)将耐热多孔网络基体1的A面，贴合到高分子材料涂层表面；
4)过热压辊以保证耐热多孔网络基体与高分子材料涂层的有效一致结合；
5)冷却至室温后，用刮刀将耐热多孔网络基体/高分子涂层复合膜从不锈钢基底上取下；
6)在耐热多孔网络基体/高分子涂层复合膜的B面，通过PVD方法制备一定厚度的第二金属N；
7)利用有机溶剂将A面上的高分子涂层溶解并且清洗干净，使得A面的耐热多孔网络基体完全露出；
8)在多孔网络基体的A面，通过PVD方法制备一定厚度的第一金属M；
9)过热压辊以保证A、B面两侧的金属M、N与其紧密贴合；
10)收卷。
本领域技术人员可以理解，根据本发明的双极性集流体可以通过任何其他方法制备，而不限于上述举例说明的方法。例如PVD法可以用CVD(Chemical Vapor Deposition，化学气相沉积)法、电镀等其他方法进行。
PVD(Physical Vapor Deposition，物理气相沉积)：是指在真空条件下，采用低电压、大电流的电弧放电技术，利用气体放电使靶材蒸发并使被蒸发物质与气体都发生电离，利 用电场的加速作用，使被蒸发物质及其反应产物沉积在工件上。与CVD工艺相比，PVD工艺处理温度低，薄膜内部应力状态为压应力，PVD工艺对环境无不利影响，符合现代绿色制造的发展方向。
需要说明的是，本发明的具体实施方式中，以锂离子电池作为电化学装置的例子来实现电化学装置，但是该电化学装置并不仅限于锂离子电池。
以下，举出实施例及比较例来对本发明的实施方式进行更具体地说明。各种的试验及评价按照下述的方法进行。另外，只要无特别说明，“份”、“％”为重量基准。
实施例1
<双极性极片的制备>
<双极性集流体的制备>
1)在不锈钢基板表面利用静电喷涂方法制备一层PVDF(聚偏氟乙烯)颗粒涂层；厚度为45μm；
2)180℃热处理使PVDF层达到软化温度；
3)将厚度为140μm的PI(聚酰亚胺)多孔薄膜的A面，贴合到PVDF涂层表面，聚酰亚胺多孔薄膜的孔隙率为60％；
4)过热压辊180℃以保证PI多孔薄膜与PVDF涂层的有效一致结合；
5)冷却至室温后，用刮刀将PI多孔薄膜与PVDF涂层复合膜从不锈钢基底上取下；
6)在PI多孔薄膜与PVDF涂层复合膜的B面，通过PVD方法制备厚度(L2’)为95μm的Al；
7)利用DMF(N,N-二甲基甲酰胺)将A面上的PVDF溶解并且清洗干净，使得A面的PI多孔薄膜基体完全露出；
8)在PI多孔薄膜的A面，通过PVD方法制备厚度(L1’)为45μm的Cu；
9)过热压辊200℃使A、B面两侧的金属Al、Cu与其紧密贴合，并将复合集流体的总厚度压薄至100μm，其中，Al层厚度约66.66μm，Cu层厚度约33.33μm；
10)收卷。
<双极性极片中负极活性物质层的制备>
将负极活性材料石墨、Super P(导电炭黑)、SBR(丁苯橡胶)按照质量比96：1.5：2.5进行混合，然后加入去离子水作为溶剂，调配成为固含量为70％的浆料，并搅拌均匀。将浆料均匀涂覆在双极性集流体的其中一面上，110℃条件下烘干，得到负极活性物质层， 负极活性物质层厚度为130μm。
<双极性极片中正极活性物质层的制备>
将正极活性材料LiCoO 2(钴酸锂)、导电炭黑、PVDF按照质量比97.5：1.0：1.5进行混合，然后加入NMP(N-甲基吡咯烷酮)作为溶剂，调配成为固含量为75％的浆料，并搅拌均匀。将浆料均匀涂覆在双极性集流体的另一面上，90℃条件下烘干，得到正极活性物质层，其中，正极活性物质层厚度为110μm。
上述步骤完成后，即得到双极性极片，将极片裁切为41mm×61mm规格待用。
<负极极片的制备>
将负极活性材料石墨、导电炭黑、丁苯橡胶按照质量比96：1.5：2.5进行混合，加入去离子水作为溶剂，调配成为固含量为70％的浆料，搅拌均匀。将浆料均匀涂覆在厚度为10μm的铜箔的一个表面上，110℃条件下烘干，得到涂层厚度为150μm层厚的单面涂覆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覆步骤。涂覆完成后，将极片裁切成41mm×61mm的规格并焊接极耳后待用。
<正极极片的制备>
将正极活性材料LiCoO 2、导电炭黑、PVDF按照质量比97.5：1.0：1.5进行混合，加入NMP作为溶剂，调配成为固含量为75％的浆料，搅拌均匀。将浆料均匀涂覆在厚度为12μm，的铝箔的一个表面上，90℃条件下烘干，得到涂层厚度为100μm的单面涂覆正极活性材料层的正极极片。然后在该正极极片的另一个表面上重复以上步骤。涂覆完成后，将极片裁切成38mm×58mm的规格并焊接极耳待用。
<电解液的制备>
在干燥氩气气氛中，首先将有机溶剂EC(碳酸乙烯酯)、EMC(碳酸甲乙酯)和DEC(碳酸二乙酯)以质量比EC：EMC：DEC＝30：50：20混合，然后向有机溶剂中加入LiPF 6(六氟磷酸锂)溶解并混合均匀，得到锂盐浓度为1.15M的电解液。
<电极组件的制备>
选用厚度15μm的PE(聚乙烯)膜作为隔离膜，负极极片的两面分别放置一片正极极片，正极极片与负极极片之间放置一层隔离膜，组成叠片，然后将整个叠片结构的四个角固定好，得到电极组件A。
选用厚度15μm的PE膜作为隔离膜，正极极片的两面分别放置一片负极极片，正极极片与负极极片之间放置一层隔离膜，组成叠片，然后将整个叠片结构的四个角固定好， 得到电极组件B。
<双极性锂离子电池的制备>
<双极性电极组件的制备>
将冲坑成型的包装膜(铝塑膜)，厚度为90μm，置于组装夹具内，坑面朝上，后将电极组件A置于坑内，使电极组件A的正极极片朝上，然后将双面涂覆双极性极片负极涂层朝下，置于电极组件A上，使电极组件A的正极极片与双极性极片的负极活性物质涂覆区域相对应，并施加外力压紧。
将上述组装半成品置于另一组装夹具内，双极性极片正极面朝上，将电极组件B置于双极性集流体之上，其中电极组件B负极与双极性极片的正极活性材料层对应，然后将冲坑成型的另一厚度为90μm的铝塑膜坑面朝下覆盖于电极组件B之上，再采用热压的方式将两个铝塑膜热封，使电极组件A和电极组件B被双极性极片分隔，得到双极性电极组件。该双极性电极组件具有两个独立的腔体，其中，电极组件A对应第一腔体，电极组件B对应第二腔体。
<电极组件注液封装>
将电解液分别注入双极性电极组件的两个腔体后封装，每个电极组件各引出一个极耳，将第一腔体中的电极组件与第二腔体中的电极组件通过双极性集流体内串联导通，得到双极性锂离子电池，该双极性锂离子电池的两个腔体间无离子交换。
实施例2
除了<双极性集流体的制备>过程中，
<双极性集流体的制备>
1)在不锈钢基板表面利用静电喷涂方法制备一层PVDF(聚偏氟乙烯)颗粒涂层；厚度为9μm：
2)180℃热处理使PVDF层达到软化温度；
3)将厚度为28μm的PI(聚酰亚胺)多孔薄膜的A面，贴合到PVDF涂层表面，聚酰亚胺多孔薄膜的孔隙率为60％；
4)过热压辊180℃以保证PI多孔薄膜与PVDF涂层的有效一致结合；
5)冷却至室温后，用刮刀将PI多孔薄膜与PVDF涂层复合膜从不锈钢基底上取下；
6)在PI多孔薄膜与PVDF涂层复合膜的B面，通过PVD方法制备厚度为19μm的Al；
7)利用DMF(N,N-二甲基甲酰胺)将A面上的PVDF溶解并且清洗干净，使得A面的PI多孔薄膜基体完全露出；
8)在PI多孔薄膜的A面，通过PVD方法制备厚度为9.00μm的Cu；
9)过热压辊200℃使A、B面两侧的金属Al、Cu与其紧密贴合，并将复合集流体的总厚度压薄至20μm，其中，Al层厚度约13.33μm，Cu层厚度约6.67μm；
10)收卷。
其余与实施例1相同。
实施例3
除了<双极性集流体的制备>过程中，调整第9)步中过热压辊的温度为220℃，使双极性集流体表面粗糙度为0.2μm以外，其余与实施例2相同。
实施例4
除了<双极性集流体的制备>过程中，调整第9)步中过热压辊的温度为230℃，使双极性集流体表面粗糙度为0.05μm以外，其余与实施例2相同。
实施例5
除了<双极性集流体的制备>过程中，通过PVD制备厚度为26.67μm的Al，厚度为1.33μm的Cu，使过热压辊后Al的厚度为19.05μm；改变Cu的厚度为0.95μm以外。其余与实施例2相同。
实施例6
除了<双极性集流体的制备>过程中，通过PVD制备厚度为5.60μm的Al，厚度为22.40μm的Cu，使过热压辊后Al的厚度为4.00μm；改变Cu的厚度为16.00μm以外。其余与实施例2相同。
实施例7
除了<双极性集流体的制备>过程中，通过PVD制备厚度为1.33μm的Al，厚度为26.67μm的Cu，使过热压辊后Al的厚度为0.95μm；改变Cu的厚度为19.05μm以外。其余与实施例2相同。
实施例8
除了<双极性集流体的制备>过程中，在B面制备Ti；在A面制备Ti，PI多孔薄膜的孔隙率为20％以外。其余与实施例5相同。
实施例9
除了<双极性集流体的制备>过程中，PI多孔薄膜的孔隙率为40％，调整Z向电子电阻率为2.00×10 -7Ω·cm以外，其余与实施例6相同。
实施例10
除了<双极性集流体的制备>过程中，将PI多孔薄膜替换为Ni多孔基体，Ni多孔基体的孔隙率为90％；6)在Ni多孔基体与PVDF涂层复合膜的B面，通过PVD方法制备厚度为14.00μm的Ag；
8)在Ni多孔基体的A面，通过PVD方法制备厚度为14.00μm的Ag。以外，其余与实施例2相同。
实施例11
除了<双极性集流体的制备>过程中，将PI多孔薄膜替换为碳毡多孔基体以外，其余与实施例6相同。
实施例12
除了<双极性集流体的制备>过程中，将PI多孔薄膜替换为PET(聚对苯二甲酸乙二醇酯)多孔基体以外，其余与实施例6相同。
实施例13
除了<双极性集流体的制备>过程中，将PI多孔薄膜替换为不锈钢多孔基体以外，其余与实施例6相同。
实施例14
除了<双极性集流体的制备>过程中，在A面制备Ni以外。其余与实施例6相同。
实施例15
除了<双极性集流体的制备>过程中，在A面制备Ti以外。其余与实施例6相同。
实施例16
除了<双极性集流体的制备>过程中，在B面制备Ni以外。其余与实施例6相同。
实施例17
除了<双极性集流体的制备>过程中，在B面制备Ti以外。其余与实施例6相同。
实施例18
除了<双极性集流体的制备>过程中，
<双极性集流体的制备>
1)在不锈钢基板表面利用静电喷涂方法制备一层PVDF(聚偏氟乙烯)颗粒涂层；厚 度为450μm：
2)180℃热处理使PVDF层达到软化温度；
3)将厚度为1400μm的PI(聚酰亚胺)多孔薄膜的A面，贴合到PVDF涂层表面，聚酰亚胺多孔薄膜的孔隙率为60％；
4)过热压辊180℃以保证PI多孔薄膜与PVDF涂层的有效一致结合；
5)冷却至室温后，用刮刀将PI多孔薄膜与PVDF涂层复合膜从不锈钢基底上取下；
6)在PI多孔薄膜与PVDF涂层复合膜的B面，通过PVD方法制备厚度为280μm的Al；
7)利用DMF(N,N-二甲基甲酰胺)将A面上的PVDF溶解并且清洗干净，使得A面的PI多孔薄膜基体完全露出；
8)在PI多孔薄膜的A面，通过PVD方法制备厚度为1120μm的Cu；
9)过热压辊200℃使A、B面两侧的金属Al、Cu与其紧密贴合，并将复合集流体的总厚度压薄至1000μm，其中，Al层厚度约200.00μm，Cu层厚度约800.00μm；
10)收卷。
其余与实施例1相同。
实施例19
除了<双极性集流体的制备>过程中，
<双极性集流体的制备>
1)在不锈钢基板表面利用静电喷涂方法制备一层PVDF(聚偏氟乙烯)颗粒涂层；厚度为4.5μm：
2)180℃热处理使PVDF层达到软化温度；
3)将厚度为14μm的PI(聚酰亚胺)多孔薄膜的A面，贴合到PVDF涂层表面，聚酰亚胺多孔薄膜的孔隙率为60％；
4)过热压辊180℃以保证PI多孔薄膜与PVDF涂层的有效一致结合；
5)冷却至室温后，用刮刀将PI多孔薄膜与PVDF涂层复合膜从不锈钢基底上取下；
6)在PI多孔薄膜与PVDF涂层复合膜的B面，通过PVD方法制备厚度为2.80μm的Al；
7)利用DMF(N,N-二甲基甲酰胺)将A面上的PVDF溶解并且清洗干净，使得A面的PI多孔薄膜基体完全露出；
8)在PI多孔薄膜的A面，通过PVD方法制备厚度为11.20μm的Cu；
9)过热压辊200℃使A、B面两侧的金属Al、Cu与其紧密贴合，并将复合集流体的总厚度压薄至10μm，其中，Al层厚度约2.00μm，Cu层厚度约8.00μm；
10)收卷。
其余与实施例1相同。
实施例20
除了<双极性集流体的制备>过程中，
<双极性集流体的制备>
1)在不锈钢基板表面利用静电喷涂方法制备一层PVDF(聚偏氟乙烯)颗粒涂层；厚度为0.9μm：
2)180℃热处理使PVDF层达到软化温度；
3)将厚度为0.28μm的PI(聚酰亚胺)多孔薄膜的A面，贴合到PVDF涂层表面，聚酰亚胺多孔薄膜的孔隙率为60％；
4)过热压辊180℃以保证PI多孔薄膜与PVDF涂层的有效一致结合；
5)冷却至室温后，用刮刀将PI多孔薄膜与PVDF涂层复合膜从不锈钢基底上取下；
6)在PI多孔薄膜与PVDF涂层复合膜的B面，通过PVD方法制备厚度为0.56μm的Al；
7)利用DMF(N,N-二甲基甲酰胺)将A面上的PVDF溶解并且清洗干净，使得A面的PI多孔薄膜基体完全露出；
8)在PI多孔薄膜的A面，通过PVD方法制备厚度为2.24μm的Cu；
9)过热压辊200℃使A、B面两侧的金属Al、Cu与其紧密贴合，并将复合集流体的总厚度压薄至2μm，其中，Al层厚度约0.40μm，Cu层厚度约1.60μm；
10)收卷。
其余与实施例1相同。
实施例21
在双极性极片中增加负极底涂层和正极底涂层，具体数据见表1，其余与实施例19相同。
<双极性极片中负极底涂层的制备>
将导电炭黑、丁苯橡胶按照质量比95：5进行混合，加入去离子水作为溶剂，调配成 为固含量为80％的浆料，搅拌均匀。将浆料均匀涂覆在复合双极性集流体A面上，110℃条件下烘干，得到负极底涂层，厚度为5μm。
<双极性极片中负极活性物质层的制备>
将负极活性材料石墨、导电炭黑、丁苯橡胶按照质量比96：1.5：2.5进行混合，加入去离子水作为溶剂，调配成为固含量为70％的浆料，搅拌均匀。将浆料均匀涂覆在负极底涂层上，110℃条件下烘干，得到负极极片，厚度为120μm。
<双极性极片中正极底涂层的制备>
将导电炭黑、丁苯橡胶按照质量比97：3进行混合，加入去离子水作为溶剂，调配成为固含量为85％的浆料，搅拌均匀。将浆料均匀涂覆在复合双极性集流体B面上，110℃条件下烘干，得到正极底涂层，厚度为3μm。
<双极性极片中正极活性物质层的制备>
将正极活性材料LiCoO 2、导电炭黑、PVDF按照质量比97.5：1.0：1.5进行混合，加入NMP作为溶剂，调配成为固含量为75％的浆料，搅拌均匀。将浆料均匀涂覆在正极底涂层上，90℃条件下烘干，得到正极极片，厚度为100μm。
实施例22
除了<双极性极片中负极底涂层的制备>过程中：将Ppy(聚吡咯)、丁苯橡胶按照质量比95：5进行混合，加入去离子水作为溶剂，调配成为固含量为80％的浆料，搅拌均匀。将浆料均匀涂覆在复合双极性集流体A面上，110℃条件下烘干，得到负极底涂层，负极底涂层的厚度为3μm。
<双极性极片中正极底涂层的制备>过程中：将Ppy(聚吡咯)、丁苯橡胶按照重量比97：3进行混合，加入去离子水作为溶剂，调配成为固含量为85％的浆料，搅拌均匀。将浆料均匀涂覆在复合双极性集流体B面上，110℃条件下烘干，得到正极底涂层，正极底涂层的厚度为3μm。其余与实施例21相同。
实施例23
<电极组件的制备>
将双面涂覆负极极片、隔膜、双面涂覆正极极片依次层叠设置组成叠片，然后将整个叠片进行卷绕，负极极片置于最外侧。其中，隔膜选用厚度15μm的聚乙烯(PE)膜。将双面涂覆负极极片、隔膜、双面涂覆正极极片依次层叠设置组成叠片，然后将整个叠片卷绕，正极极片置于最外侧。其中，隔膜选用厚度15μm的聚乙烯(PE)膜。
<双极性锂离子电池的制备>
<双极性电极组件的制备>
将冲坑成型的铝塑膜，置于组装夹具内，坑面朝上，将电极组件A置于坑内，然后将双极性集流体包含正极活性材料的一面朝下，放置于电极组件A上，使得活性材料涂覆区域相对应，施加外力压紧得到组装半成品。
将组装半成品置于另一组装夹具内，双极性集流体包含负极活性材料的一面朝上，将电极组件B放置于双极性集流体上，使得活性材料涂覆区域对应，施加外力压紧，然后将冲坑成型的铝塑膜坑面朝下覆盖于电极组件B上，采用热压的方式热封四周，得到组装电极组件。其余与实施例19相同。
对比例1
除了双极性集流体选择Cu/Al复合箔集流体外，其余与实施例1相同。
Cu/Al复合集流体厚度为20μm。
对比例2
除了双极性集流体选择不锈钢箔集流体外，其余与实施例1相同。
不锈钢箔集流体厚度为20μm。
对比例3
除了双极性集流体为零维结构导电材料与高分子基材复合得到的以外，其余与实施例1相同。
双极性集流体中，零维结构导电材料为点状炭黑颗粒，高分子基材为PET基材，点状炭黑颗粒均匀无取向地分散在三维分布的基体中，双极性集流体厚度约50μm。
对比例4
除了双极性集流体为一维结构导电材料与高分子基材复合得到的以外，其余与实施例1相同。
双极性集流体中，一维结构导电材料为MWCNT，高分子基材为PET基材，MWCNT均匀无取向地分散在三维分布的基体中，双极性集流体厚度约50μm。
对比例5
除了双极性集流体为二维结构导电材料与高分子基材复合得到的以外，其余与实施例1相同。
双极性集流体中，二维结构导电材料为石墨烯，高分子基材为PET基材，石墨烯均匀 无取向地分散在三维分布的基体中，双极性集流体厚度约50μm。
<性能测试>
使用下述方法对各实施例及各对比例制得的双极性集流体、双极性锂离子电池进行测试：
材料表面粗糙度的测试
这是一种接触式测量方法，是利用仪器的测针与被测表面相接触，并使测针沿其表面轻轻划过以测量表面粗糙度的一种测量法。将一个很尖的触针垂直安置在被测表面上作横向移动，由于工作表面粗糙不平，因而触针将随着被测表面轮廓形状作垂直起伏运动。将这种微小位移通过电路转换成电信号并加以放大和运算处理，即可得到工件表面粗糙度参数值；也可通过记录器描绘出表面轮廓图形，再进行数据处理，进而得出表面粗糙度参数值。
具体测试方法为：取样长度(10cm)内5个最大的轮廓峰高平均值与5个最大轮廓谷深平均值之差。该方法适宜测量的表面粗糙度Rz范围为0.02μm至160μm。
复合双极性集流体M、N层厚度方向比值测试
制备样品的截面样品，测量SEM(Scanning Electron Microscope，扫描电子显微镜)并做元素分析，找出M与N的界面，界面至M层外缘距离为L1，界面至N层外缘距离为L2，L1与L2的比值即为该数值。
双极性集流体层厚度记作H。
Z方向电子电阻率R测试
复合双极性集流体两面用固定面积夹板夹住，测量电阻值，随后除以厚度并乘以板面积即可得到。
膜片与双极性集流体粘结力测试
1)将极片从未经过充放电循环的电极组件，即新鲜的电极组件中取出，切成宽度为3cm，长度10-16cm的长条；
2)在钢板表面贴宽度2cm，长度9-15cm的专用强力双面胶带；
3)将截取的极片试样贴在双面胶上，测试面向下；将宽度与极片等宽，长度大于极片试样长度8-20cm的纸带插入极片下方，并且用皱纹胶固定；
4)将钢板未贴极片的一端用夹具固定，竖直放置钢板，将纸带向上翻折，用上夹具固定；
5)竖直向上以5cm/min速度拉纸带，将胶带和粘附的膜片涂膜区与集流体间拉开，测量拉开时得到的力，计算所测得的力与上极片宽度的比值，多次测量取平均值，即为粘结力。
与正极极片的粘结力为F +，与负极极片的粘结力为F -。
放电能量密度ED测试
将锂离子电池在常温下静置30分钟，以0.05C充电速率恒流充电至电压至8.8V(额定电压)，随后再以0.05C倍率将电化学装置放电至6.0V，重复上述充/放电步骤3个循环以完成待测的电化学装置的化成。完成电化学装置的化成后，以0.1C充电速率恒流充电至电压至8.8V，随后以0.1C放电倍率将电化学装置放电至6.0V，纪录其放电容量，随后计算其0.1C放电时的能量密度：
质量能量密度(Wh/kg)＝放电能量(Wh)/锂离子电池重量(kg)
50循环后的放电容量/首次放电容量Q50/Q0(％)
测试温度为25℃，以0.5C恒流充电到8.8V，恒压充电到0.025C，静置5分钟后以0.5C放电到6.0V，以此步得到的容量为初始容量，再以0.5C充电/0.5C放电循环测试50次后，计算锂离子电池的容量与初始容量的比值。
表1各实施例及对比例的测试参数以及相应的实验结果
Figure PCTCN2020099422-appb-000001
Figure PCTCN2020099422-appb-000002
如表1所示，相较于对比例1和对比例2，即相较于普通Cu/Al复合箔集流体和普通不锈钢箔集流体的锂离子电池，本发明实施例中的锂离子电池的能量密度、50次循环后的放电容量与首次放电容量的比值、膜片与双极性集流体的粘结力都增大。
相较于对比例3-5，本发明实施例给出的锂离子电池的能量密度基本不发生变化，本发明实施例1-2、6、9-23的50次循环后的放电容量与首次放电容量的比值增大，本发明实施例的膜片与双极性集流体粘结力都增大。
从实施例1-4可以看出，随着双极性集流体的表面粗糙度增大，双极性集流体与正负极极片的粘结力呈增大趋势；从实施例5-7可以看出，随着双极性集流体厚度方向比值增大，锂离子电池的质量能量密度呈减小趋势，50次充放电循环的放电容量与首次放电容量的比值先增大后减小，综合考虑，厚度方向的比值不宜过大或过小；从实施例17-20可以看出，随着双极性集流体的厚度增大，锂离子电池的质量能量密度减小，50次充放电循环的电容量与首次放电容量的比值先增大后减小，综合考虑，双极性集流体的厚度不宜过厚或过薄。
综上所述，本发明实施例的锂离子电池的性能优于对比例。
以上所述仅为本发明的较佳实施例，并不用以限制本发明，凡在本发明的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本发明保护的范围之内。

Claims (13)

  1. 一种双极性集流体，其包括多孔基体、第一金属M、第二金属N，所述多孔基体的一个表面存在所述第一金属M，另一个表面存在所述第二金属N，所述多孔基体的内部存在所述第一金属M或所述第二金属N中的至少一种；
    所述多孔基体的材料包括碳材料、高分子材料或第三金属中的至少一种；
    所述多孔基体的孔隙率为20％至90％。
  2. 根据权利要求1所述的双极性集流体，其中，所述碳材料包括单壁碳纳米管膜、多壁碳纳米管膜、碳毡、多孔碳膜、炭黑、乙炔黑、富勒烯、导电石墨或石墨烯中的至少一种。
  3. 根据权利要求1所述的双极性集流体，其中，所述高分子材料包括聚对苯二甲酸亚乙酯、聚对苯二甲酸丁二醇酯、聚萘二甲酸乙二醇酯、聚醚醚酮、聚酰亚胺、聚酰胺、聚乙二醇、聚酰胺酰亚胺、聚碳酸酯、环状聚烯烃、聚苯硫醚、聚乙酸乙烯酯、聚四氟乙烯，聚亚甲基萘、聚偏二氟乙烯，聚萘二甲酸亚乙酯、聚碳酸亚丙酯、聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)、有机硅、维尼纶、聚丙烯、聚乙烯、聚氯乙烯、聚苯乙烯、聚醚腈、聚氨酯、聚苯醚、聚酯、聚砜或其衍生物中的至少一种。
  4. 根据权利要求1所述的双极性集流体，其中，所述第三金属、第一金属M、第二金属N各自独立地包括Cu、Al、Ni、Ti、Ag、Au、Pt或不锈钢中的至少一种。
  5. 根据权利要求1所述的双极性集流体，其中，所述第一金属M在所述多孔基体表面形成的层的厚度为0.95μm至900μm；所述第二金属N在所述多孔基体表面形成的层的厚度为0.95μm至900μm。
  6. 根据权利要求1所述的双极性集流体，其中，所述双极性集流体的厚度为2μm至1000μm。
  7. 根据权利要求1所述的双极性集流体，其中，所述双极性集流体的表面粗糙度为0.05μm至10μm。
  8. 根据权利要求1所述的双极性集流体，其中，所述第一金属M在所述多孔基体表面形成的层与第二金属N在所述多孔基体表面形成的层的厚度比为0.05至20。
  9. 根据权利要求1所述的双极性集流体，其中，所述双极性集流体的Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -4Ω·cm。
  10. 根据权利要求1所述的双极性集流体，其中，所述双极性集流体满足以下特征中的至少一者：
    (a)所述双极性集流体的厚度为5μm至50μm；
    (b)所述双极性集流体的表面粗糙度为0.2μm至5μm；
    (c)所述第一金属M在所述多孔基体表面形成的层与第二金属N在所述多孔基体表面形成的层的厚度比为0.2至5；
    (d)所述双极性集流体Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -6Ω·cm；
    (e)所述多孔基体的孔隙率为40％至70％。
  11. 根据权利要求1所述的双极性集流体，其中，所述双极性集流体满足以下特征中的至少一者：
    (a)所述第一金属M在所述多孔基体表面形成的层的厚度为0.40μm至13.33μm；所述第二金属N在所述多孔基体表面形成的层的厚度为0.40μm至13.33μm；
    (b)所述双极性集流体的厚度为5μm至20μm；
    (c)所述双极性集流体的表面粗糙度为0.5μm至2μm；
    (d)所述双极性集流体Z方向电子电阻率为2.00×10 -10Ω·cm至2.00×10 -8Ω·cm。
  12. 一种电化学装置，包括至少两个电极组件以及权利要求1-11任一项所述的双极性集流体，所述双极性集流体位于两个电极组件之间。
  13. 一种电子装置，所述电子装置包括权利要求12所述的电化学装置。
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