WO2022000329A1 - 一种电化学装置及电子装置 - Google Patents

一种电化学装置及电子装置 Download PDF

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Publication number
WO2022000329A1
WO2022000329A1 PCT/CN2020/099510 CN2020099510W WO2022000329A1 WO 2022000329 A1 WO2022000329 A1 WO 2022000329A1 CN 2020099510 W CN2020099510 W CN 2020099510W WO 2022000329 A1 WO2022000329 A1 WO 2022000329A1
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Prior art keywords
current collector
bipolar current
electrode
active material
electrochemical device
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PCT/CN2020/099510
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English (en)
French (fr)
Inventor
严坤
丁宇
张益博
张楠
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宁德新能源科技有限公司
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Priority to CN202080053225.7A priority Critical patent/CN114175299A/zh
Priority to PCT/CN2020/099510 priority patent/WO2022000329A1/zh
Publication of WO2022000329A1 publication Critical patent/WO2022000329A1/zh
Priority to US17/709,943 priority patent/US20220223983A1/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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0413—Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes
    • H01M10/0418—Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes with bipolar electrodes
    • 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
    • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • H01M10/482—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte for several batteries or cells simultaneously or sequentially
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • 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
    • H01M4/669—Steels
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/102—Primary casings, jackets or wrappings of a single cell or a single battery characterised by their shape or physical structure
    • H01M50/105—Pouches or flexible bags
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings, jackets or wrappings of a single cell or a single battery
    • H01M50/183—Sealing members
    • H01M50/19—Sealing members characterised by the material
    • H01M50/193—Organic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/54—Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges
    • 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
    • H01M50/569—Constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals
    • 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

Definitions

  • the present invention relates to the field of electrochemistry, and in particular, to an electrochemical device and an electronic device including the electrochemical device.
  • the open circuit voltage of the battery is difficult to exceed 5V.
  • 5V electric vehicles
  • PT power tools
  • ESS energy storage systems
  • the demand also requires an increase in the open-circuit voltage of the cell.
  • the method of connecting multiple batteries in series is generally used to increase the output voltage, but there are many problems in the series connection of multiple batteries.
  • the concept of high output voltage battery which uses the internal series connection of the battery to realize the high voltage output of a single battery, reduces the total heat generation of the battery, and reduces the temperature rise during use.
  • the series battery in the prior art is to directly connect two batteries in series in the same packaging bag, which does not do ionic insulation for the two series batteries. If the battery voltage increases, the electrolyte is decomposed under high voltage conditions, which will cause The battery fails; in addition, an internal short circuit will occur between the two batteries due to the voltage difference between the pole pieces, which will also cause the battery to fail.
  • the solutions proposed so far are only applicable to solid-state electrolyte batteries.
  • the mainstream lithium battery is a liquid electrolyte, so the above scheme is difficult to promote.
  • the purpose of the present application is to provide an electrochemical device that achieves high voltage output while having high energy density.
  • a first aspect of the present application provides an electrochemical device, comprising a bipolar current collector, the bipolar current collector is hermetically connected to an outer package, and independent cavities are formed on both sides of the bipolar current collector. An electrode assembly and an electrolyte are encapsulated in each cavity. An electrode active material is provided on at least one surface of the bipolar current collector. The electrode assemblies in adjacent cavities are connected in series.
  • the cavity is a sealed cavity.
  • an electrode active material is provided on the first surface of the bipolar current collector.
  • the polarity of the electrode active material is opposite to the polarity of the outermost electrode piece of the adjacent electrode assembly.
  • a diaphragm is provided between the outermost electrode sheet and the bipolar current collector.
  • the second surface of the bipolar current collector is electrically insulated from adjacent electrode assemblies.
  • the bipolar current collector is provided with a tab, and the tab is connected in parallel with the tab of the same polarity in the electrode assembly adjacent to the first surface.
  • the bipolar current collector has a thickness of 6 ⁇ m to 100 ⁇ m, preferably 10 ⁇ m to 55 ⁇ m.
  • the bipolar current collector has a thickness of 10 ⁇ m to 40 ⁇ m, preferably 20 ⁇ m to 30 ⁇ m.
  • an electrode active material is provided on the first surface of the bipolar current collector, and the electrode active material has a polarity with the outermost electrode sheet of an adjacent electrode assembly.
  • the second surface of the bipolar current collector is electrically connected to the current collector of the outermost electrode pad of the adjacent electrode assembly, and the polarity of the electrode pad adjacent to the second surface is the same as the polarity of the first electrode pad.
  • the polarity of the electrode active material on one surface is opposite.
  • two surfaces of the bipolar current collector are respectively provided with electrode active materials of different polarities, and the outermost electrode sheet of the electrode assembly adjacent to each surface is Different from the polarity of the electrode active material on the surface, a separator is provided between the outermost electrode piece of the electrode assembly and the bipolar current collector.
  • the electrochemical device is provided with two tabs of opposite polarities, and an electrode assembly of the electrochemical device is connected in series between the two tabs.
  • each of the electrode assemblies is provided with two tabs of opposite polarities, wherein one tab is connected in series with tabs of opposite polarities of an adjacent electrode assembly.
  • the bipolar current collector is further provided with a tab, which is used to detect the operation state of the electrode assemblies on both sides of the bipolar current collector.
  • the bipolar current collector is further provided with a tab, and the tab is connected to a tab connecting the electrode assemblies on both sides of the bipolar current collector in series with each other .
  • a second aspect of the present application provides an electronic device, which includes the electrochemical device provided by the first aspect of the present application.
  • the bipolar current collector not only has the function of physical isolation, but also completely isolates the electrode assemblies on both sides of the bipolar current collector to form an independent sealed cavity, which ensures the normal operation of the electrochemical device and improves the performance of the electrochemical device.
  • the safety of the electrochemical device; and the electrode active material on the surface of the bipolar current collector also participates in the electrochemical reaction process in the electrochemical device, so that the electrochemical device achieves a high voltage output and has a high energy density.
  • the bipolar current collector is hermetically connected to the outer package, so a liquid electrolyte can be used, which can meet the market demand.
  • FIG. 1 is a schematic diagram of an electrochemical device in an embodiment of the application.
  • FIG. 2 is a partial schematic cross-sectional view of an internal structure of an electrochemical device in an embodiment of the present application
  • FIG. 3 is a partial schematic cross-sectional view of the internal structure of an electrochemical device in another embodiment of the present application.
  • FIG. 4 is a schematic diagram of an electrochemical device in another embodiment of the present application.
  • FIG. 5 is a partial schematic cross-sectional view of the internal structure of an electrochemical device in another embodiment of the present application.
  • FIG. 6 is a schematic structural diagram of a bipolar current collector in an embodiment of the present application.
  • the electrochemical device of the present application can be any electrochemical device known to those skilled in the art, such as lithium ion batteries, sodium ion batteries, magnesium ion batteries, supercapacitors, etc.
  • the following description takes lithium ion batteries as an example. It should be understood by those skilled in the art that the following descriptions are only examples and do not limit the protection scope of the present application.
  • the application provides an electrochemical device, which includes a bipolar current collector, the bipolar current collector is sealed with an outer package, and independent sealed cavities are formed on both sides of the bipolar current collector, each An electrode assembly and an electrolyte are encapsulated in the sealed cavity, an electrode active material is provided on at least one surface of the bipolar current collector, and the electrode assemblies in adjacent sealed cavities are connected in series.
  • FIG. 1 shows an embodiment of the present application, which includes a bipolar current collector 1 , the bipolar current collector 1 is sealed with an outer package 3 , and two sides of the bipolar current collector 1 are formed with respective Independent cavities, each cavity contains an electrode assembly 2 and an electrolyte, at least one surface of the bipolar current collector 1 contains electrode active materials, and adjacent electrode assemblies 2 are connected in series.
  • the cavity is a sealed cavity.
  • the bipolar current collector in this application refers to a current collector whose two sides can be coated with active materials of different polarities at the same time, and has the characteristics of a positive electrode current collector and a negative electrode current collector at the same time.
  • the bipolar current collector is hermetically connected to the outer package, and independent sealed cavities are formed on both sides of the bipolar current collector.
  • the electrode assemblies on both sides of the bipolar current collector and the electrolytic The liquid is completely separated, which can not only ensure the normal operation of the electrode assemblies on both sides, but also improve the safety of the electrochemical device with good sealing performance.
  • the bipolar current collector has the characteristics of electronic conduction and ion insulation, which can avoid the occurrence of internal short circuits, high-voltage decomposition of electrolytes, and internal short circuits in electrode assemblies.
  • At least one surface of the bipolar current collector is provided with an electrode active material, and the existence of the electrode active material enables the bipolar current collector to participate in the electrochemical reaction of the electrochemical device, which can effectively improve the energy density of the electrochemical device.
  • Connecting adjacent electrode assemblies in series can achieve high voltage output, which can meet the needs of the existing market.
  • an electrode active material is provided on the first surface of the bipolar current collector, and the electrode active material is opposite in polarity to the outermost electrode sheet of the adjacent electrode assembly, so A diaphragm is arranged between the outermost electrode piece and the bipolar current collector; the second surface of the bipolar current collector is electrically insulated from the adjacent electrode assemblies.
  • the first surface of the bipolar current collector and the outermost electrode piece of the adjacent electrode assembly constitute an electrochemical unit, which participates in the charging and discharging process of the electrochemical device and improves the energy of the electrochemical device density.
  • a tab is provided on the bipolar current collector, and the tab is connected in parallel with the tab with the same polarity in the electrode assembly adjacent to the first surface.
  • the tabs are connected in parallel with the electrode assemblies adjacent to the second surface of the bipolar current collector in series, thereby providing a high output voltage.
  • FIG. 2 shows an embodiment of the present application
  • the bipolar current collector 1 is provided with a positive electrode active material 7 on the a surface
  • the b surface has no electrode active material
  • the outermost electrode assembly 201 adjacent to the a surface is
  • the layer is provided with a negative electrode active material 8
  • the outermost layer of the electrode assembly 202 adjacent to the b surface is provided with a diaphragm 9
  • the bipolar current collector 1 is provided with a tab 4 (as shown in FIG.
  • the tab 4 of 1 is connected to the positive tab of the electrode assembly 201 on the side adjacent to the a surface of the bipolar current collector to form a parallel connection, and then connected to the negative tab of the electrode assembly 202 to form a series connection to realize the connection between the electrode assemblies 201 and 202. concatenate.
  • the positive electrode active material on the a surface of the bipolar current collector can also be a negative electrode active material.
  • the outermost layer of the electrode assembly 201 adjacent to the a surface includes the positive electrode active material
  • the tab of the bipolar current collector is connected to the negative tab of the electrode assembly 201 to form a parallel connection, and then connected to the positive tab of the electrode assembly 202 to form a series connection.
  • an electrode active material is provided on the first surface of the bipolar current collector, and the electrode active material is opposite in polarity to the outermost electrode sheet of the adjacent electrode assembly,
  • a diaphragm is arranged between the outermost electrode sheet and the bipolar current collector; the second surface of the bipolar current collector is connected to the current collector of the outermost electrode sheet of the adjacent electrode assembly
  • the polarity of the outermost electrode pads of the electrode assemblies adjacent to the second surface is opposite to the polarity of the electrode active material on the first surface.
  • the bipolar current collector may not lead out the tabs.
  • the electrode assemblies on both sides of the bipolar current collector are directly connected in series through the bipolar current collector, and the electrochemical The device can only lead out two polar tabs with opposite polarities, wherein all electrode assemblies are connected in series between the two polar tabs with opposite polarities through bipolar current collectors.
  • the bipolar current collector may also lead out a tab, and the tab is connected to the same polarity tab on the electrode assembly on the side where the electrode active material is arranged on the bipolar current collector, A parallel connection is formed, and then it is connected to the opposite polarity tabs on the electrode assembly on the other side to form a series connection.
  • the middle of the two electrode assemblies can be connected in series through the bipolar current collector inside and through the outside of the tabs.
  • the tabs of the bipolar current collector may not be connected to the tabs of the electrode assembly, and are only used to monitor the voltage of the electrochemical device.
  • FIG. 3 shows an embodiment of the present application
  • the a-side of the bipolar current collector contains negative active material 8
  • the b-side of the bipolar current collector 1 has no electrode active material
  • the bipolar current collector 1 has no electrode active material on the b side.
  • the outermost layer of the electrode assembly 201 adjacent to the a surface is provided with the positive electrode active material 7, and the outermost layer of the electrode assembly 202 adjacent to the b surface of the bipolar current collector 1 is the positive electrode current collector 10.
  • the b-side of the bipolar current collector 1 forms an electrical connection.
  • the electrode assembly 201 and the electrode assembly 202 can be directly connected in series through the bipolar current collector 1, and the positive tab of the electrode assembly 201 and the negative tab of the electrode assembly 202 can be drawn out as the charge and discharge tabs of the electrochemical device.
  • a bipolar current collector is provided with a tab, the tab is connected to the negative tab of the electrode assembly 201 to form a parallel connection, and then connected to the positive tab of the electrode assembly 202 to form a series connection, At this time, the two electrode assemblies are connected in series internally through the bipolar current collector and externally through the tabs.
  • the tabs on the bipolar current collector may not be connected to the tabs of the electrode assembly, and are only used to monitor the voltage of the electrochemical device.
  • the negative electrode active material on the a surface of the bipolar current collector can also be a positive electrode active material.
  • the outermost layer of the electrode assembly 201 adjacent to the a surface is provided with a negative electrode active material.
  • the outermost layer of the electrode assembly 202 adjacent to the b surface of the bipolar current collector 1 is the negative electrode current collector, and the electrode assembly 201 and the electrode assembly 202 can be connected in series directly through the bipolar current collector 1 .
  • two surfaces of the bipolar current collector are respectively provided with electrode active materials of different polarities, and the outermost electrode sheet of the electrode assembly adjacent to each surface is connected to the surface of the current collector.
  • the electrode active materials on the electrode assembly have different polarities, and a separator is provided between the outermost electrode sheet of the electrode assembly and the bipolar current collector.
  • the two surfaces of the bipolar current collector are respectively provided with electrode active materials with different polarities, and the two surfaces respectively form an electrochemical unit with the outermost electrode pole piece of the adjacent electrode assembly, which further improves the energy density of the battery.
  • the electrode assemblies on both sides of the bipolar current collector can directly realize internal series connection through the bipolar current collector, or can realize internal series connection and external series connection simultaneously through the bipolar current collector and two polar tabs with opposite polarities.
  • FIG. 5 shows an embodiment of the present application
  • the bipolar current collector 1 is provided with a positive electrode active material 7 on the a side
  • the bipolar current collector 1 is provided with a negative electrode active material 8 on the b side.
  • the outermost electrode piece of the electrode assembly 201 adjacent to the a surface of the polar current collector 1 contains the negative electrode active material 8, and the outermost electrode piece of the electrode assembly 202 adjacent to the b surface of the bipolar current collector 1
  • the positive electrode active material 7 is contained.
  • the electrode assembly 201 and the electrode assembly 202 can be directly connected in series through the bipolar current collector 1, and the negative electrode tab of the electrode assembly 201 and the positive electrode tab of the electrode assembly 202 are the output tabs of the electrochemical device.
  • the bipolar current collector is provided with a positive electrode active material on the a-side, a negative electrode active material on the b-side, and the outermost electrode electrode of the electrode assembly 201 adjacent to the a-side
  • the sheet contains the negative electrode active material
  • the outermost electrode sheet of the electrode assembly 202 adjacent to the b-side contains the positive electrode active material. All tabs of the electrode assemblies 201 and 202 are drawn out, the positive tabs of the electrode assembly 201 and the negative tabs of the electrode assembly 202 are connected in series. The ears are externally connected in series, and the negative electrode tab of the electrode assembly 201 and the positive electrode tab of the electrode assembly 202 are the output tabs of the electrochemical device, as shown in FIG. 4 .
  • two surfaces of the bipolar current collector are respectively provided with electrode active materials with different polarities, and a tab is provided on the bipolar current collector. It is used to monitor the voltage of the electrochemical device, or to insulate the tabs.
  • the tabs can also be connected to tabs connecting the electrode assemblies on both sides of the bipolar current collector in series.
  • the bipolar current collector is not particularly limited, as long as electrode active materials with different polarities can be provided on both surfaces thereof.
  • bipolar current collectors need to have anti-redox properties and be able to exist stably in the electrolyte, for example, the bipolar current collectors include metal bipolar current collectors or composite bipolar current collectors.
  • the metal bipolar current collector includes at least one of copper-aluminum composite current collectors, stainless steel (Ni, Ti, Ag, Au, Pt and other current collectors).
  • the composite bipolar current collector is not particularly limited, for example, a composite bipolar current collector includes a metal and a polymer, wherein the metal is disposed on the surface of the polymer, and the metals on the two surfaces can be the same or Differently, there is an electrical connection between the metals on the two surfaces.
  • the metal is not particularly limited, as long as the purpose of the present application can be achieved, for example, the metal includes two of Cu, Al, Ni, Ti, Ag, Au, Pt and the like.
  • the polymer is not particularly limited as long as it can achieve the purpose of the present application, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate Alcohol ester, polyetheretherketone, polyimide, polyamide, polyethylene glycol, polyamideimide, polycarbonate, cyclic polyolefin, polyphenylene sulfide, polyvinyl acetate, polytetrafluoroethylene , polymethylene naphthalene, polyvinylidene fluoride, polyethylene naphthalate, polypropylene carbonate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-trifluoroethylene) vinyl chloride), silicone resin, vinylon, polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyphenylene ether, polysulfone or at least
  • Another composite bipolar current collector includes a one-dimensional or two-dimensional conductive material and a polymer, and the conductive material is embedded in the polymer at a certain angle (eg, 0° to 30°) to achieve electrical conductivity in the thickness direction.
  • the conductive material includes at least one of carbon material or metal material.
  • the carbon material includes at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, conductive carbon fibers, conductive carbon black, fullerenes, conductive graphite or graphene.
  • the metal material includes at least one of Ni, Ti, Ag, Au, Pt or stainless steel and alloys thereof.
  • the polymers include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyether ether ketone, polyimide, polyamide, polyethylene glycol , polyamideimide, polycarbonate, cyclic polyolefin, polyphenylene sulfide, polyvinyl acetate, polytetrafluoroethylene, polymethylene naphthalene, polyvinylidene fluoride, polyethylene naphthalate , Polypropylene carbonate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-chlorotrifluoroethylene), silicone resin, vinylon, polypropylene, polyethylene, polyvinyl chloride , polystyrene, polyether nitrile, polyurethane, polyphenylene ether, polysulfone or at least one of the derivatives of the above substances.
  • the bipolar current collector has a thickness of 6 ⁇ m to 100 ⁇ m, preferably 10 ⁇ m to 55 ⁇ m. In some embodiments of the present application, the bipolar current collector has a thickness of 10 ⁇ m to 40 ⁇ m, preferably 20 ⁇ m to 30 ⁇ m.
  • the bipolar current collector not only has the characteristics of ion insulation, but also should have certain mechanical strength. Therefore, if the bipolar current collector is too thin, the mechanical strength is poor, and it is easy to cause damage and affect the performance and even the safety of the electrochemical device. Too thick will affect the conduction of electrons and reduce the energy density of the electrochemical device, so that the performance of the electrochemical device is limited.
  • the electron resistivity of the bipolar current collector in the Z direction is 1 ⁇ 10 ⁇ 11 to 30 ⁇ cm, preferably 1 ⁇ 10 ⁇ 5 to 5 ⁇ cm, and more preferably 0.01 to 0.10 ⁇ cm.
  • the thickness of the positive electrode active material is 30 to 120 ⁇ m; when the electrode active material on the surface of the bipolar current collector is a negative electrode active material, the negative electrode active material The thickness of the material is 30 to 120 ⁇ m.
  • the surface of the bipolar current collector contains electrode active materials, which can participate in the reaction process in the electrochemical device, which can not only improve the output voltage, but also improve the energy density of the electrochemical device. In this application, if the thickness of the electrode active material is too thin, the surface of the coating will be uneven due to the particle size of the product, and the energy that the coated substance can exert is low. If the thickness of the electrode active material is too thick, it will affect the electrical conductivity. The electrochemical reactivity of the core. Therefore, selecting the electrode active material with the above thickness is more conducive to achieving high voltage output and at the same time having a higher energy density.
  • the bipolar current collector 1 further includes a sealing area 12 , and the sealing area 12 is located at the peripheral edge of the bipolar current collector 1 .
  • the zone also contains sealing material including polypropylene, anhydride modified polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl alcohol copolymer , at least one of polyvinyl chloride, polystyrene, polyether nitrile, polyurethane, polyamide, polyester, amorphous ⁇ -olefin copolymer and derivatives thereof.
  • the selection of the above-mentioned sealing material can more effectively seal the connection with the outer package, thereby helping to improve the safety of the electrochemical device.
  • the sealing method between the bipolar current collector and the outer package there is no particular limitation on the sealing method between the bipolar current collector and the outer package, and any sealing method known in the art can be used.
  • a typical method is to set the surrounding edges of the bipolar current collector
  • the sealing material and the outer packaging are heat-pressed and sealed, and a sealing area is formed at the contact area between the sealing material and the outer packaging.
  • the polymer material in the sealing area is fused with the polymer material in the inner layer of the outer package.
  • the size of the sealing area is not particularly limited, as long as the purpose of the present application can be achieved.
  • the sealing thickness T (unit: mm) and the sealing width W (unit: mm) of the sealing area satisfy 0.01 ⁇ T/W ⁇ 0.05.
  • the seal thickness and seal width are not particularly limited, as long as the purpose of the present invention can be achieved, for example, the seal width is preferably 1 mm to 7 mm.
  • the seal thickness includes the thickness after the polymer material in the sealing material is fused with the polymer material in the inner layer of the outer package.
  • the sealing width refers to the width of the sealing area formed by the combination of the polymer material in the sealing material and the polymer material in the inner layer of the outer package after heat-press sealing.
  • the electrolyte includes one of a gel state, a solid state and a liquid state.
  • the electrolyte solution is not particularly limited as long as the purpose of the present application can be achieved.
  • the structure of the electrode assembly includes a wound structure or a laminated structure. The battery packs connected in series may have the same structure or different structures.
  • the structure of the electrode assembly is a winding structure, and the electrode assembly includes a monopole tab or a multipole tab.
  • the electrode assembly includes a monopole lug, and a positive electrode lug and a negative electrode lug are drawn from the positive pole piece and the negative pole piece respectively.
  • the electrode assembly includes multi-pole lugs, which can be drawn from each circle of positive pole pieces and negative pole pieces, respectively leading out one positive pole piece and one negative pole piece, or from two or more circles of positive pole pieces and negative pole pieces.
  • a positive electrode tab and a negative electrode tab are drawn out respectively, and finally an electrode assembly with a winding structure includes multiple groups of positive electrode tabs and negative electrode tabs, and then the lead wires of the tabs are transferred by welding.
  • the structure of the electrode assembly is a laminated structure, and the electrode assembly includes multi-pole tabs, which may be one positive tab and one negative pole drawn from each layer of positive pole piece and negative pole piece, respectively.
  • a laminated structure electrode assembly includes multiple sets of positive electrode tabs and negative electrode tabs, which are then transferred to the lead tabs through transfer welding.
  • the welding method is not particularly limited, as long as the purpose of the present application can be achieved.
  • laser welding ultrasonic welding or resistance welding, etc.
  • the series tabs are distributed in a stack or in a dislocation distribution in the thickness direction of the electrochemical device.
  • the distribution of the tabs in the present application there is no particular limitation on the distribution of the tabs in the present application, as long as the purpose of the present application can be achieved. In practical applications, the distribution of the tabs can be adjusted as required.
  • the electrode assembly mentioned in this application may be an electrode assembly including a positive electrode piece, a negative electrode piece and a separator, and the above-mentioned electrode assembly is used as an example for description. It should be understood by those skilled in the art that the following descriptions are only examples and do not limit the protection scope of the present application.
  • the positive electrode sheet is not particularly limited, as long as the purpose of the present application 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 copper foil, aluminum foil, aluminum alloy foil, composite current collector, and the like.
  • the positive electrode active material is not particularly limited, and can be any positive electrode active material in the prior art.
  • the positive electrode active material includes nickel-cobalt lithium manganate, nickel-cobalt lithium aluminate, lithium iron phosphate, lithium cobaltate, manganic acid At least one of lithium or lithium iron manganese phosphate.
  • the thicknesses of the positive electrode current collector and the positive electrode active material are not particularly limited as long as the purpose of the present application can be achieved.
  • the thickness of the cathode current collector is 8-12 ⁇ m
  • the thickness of the cathode active material is 30-120 ⁇ m.
  • the positive electrode sheet may further include a conductive layer, and the conductive layer is located between the positive electrode current collector and the positive electrode active material layer.
  • the composition of the conductive layer is not particularly limited, and may be a conductive layer commonly used in the art.
  • the conductive layer includes a conductive agent and an adhesive.
  • the negative pole piece is not particularly limited, as long as the purpose of the present application can be achieved.
  • the negative electrode sheet generally includes a negative electrode current collector and a negative electrode active material.
  • 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, composite current collector, and the like.
  • the negative electrode active material is not particularly limited, and any negative electrode active material known in the art may be used.
  • at least one of artificial graphite, natural graphite, mesocarbon microspheres, silicon, silicon carbon, silicon oxide, soft carbon, hard carbon, lithium titanate, or niobium titanate may be included.
  • the thicknesses of the negative electrode current collector and the negative electrode active material are not particularly limited as long as the purpose of the present application can be achieved.
  • the thickness of the negative electrode current collector is 6-10 ⁇ m
  • the thickness of the negative electrode active material is 30-120 ⁇ m.
  • the negative electrode sheet may further include a conductive layer, and the conductive layer is located between the negative electrode current collector and the negative electrode active material layer.
  • the composition of the conductive layer is not particularly limited, and may be a conductive layer commonly used in the art.
  • the conductive layer includes a conductive agent and an adhesive.
  • the above-mentioned conductive agent is not particularly limited, and any conductive agent known in the art can be used as long as the purpose of the present application can be achieved.
  • the conductive agent may include at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), carbon fiber or graphene, and the like.
  • the above-mentioned adhesive is not particularly limited, and any adhesive known in the art can be used as long as the purpose of the present application can be achieved.
  • the adhesive may include at least one of styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (CMC-Na), and the like. .
  • the separator is not particularly limited, as long as the purpose of the present application can be achieved.
  • the thickness of the separator may be 5-15 ⁇ m, and the separator may include polymers or inorganic substances formed from materials that are stable to the electrolyte of the present application.
  • the diaphragm may also be referred to as a separator.
  • 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 include at least one of polyethylene, polypropylene, polyethylene terephthalate and polyimide .
  • 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 tabs mentioned in this application refer to the metal conductors drawn from the positive pole piece or the negative pole piece, and are used for connecting other parts of the electrochemical device in series or in parallel.
  • the positive tab is drawn from the positive pole piece, and the negative pole tab is drawn from the negative pole piece.
  • the electrolyte solution mentioned in this application may contain 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 purpose of the present application can be achieved.
  • lithium salts may include LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiB(C 6 H 5 ) 4 , LiCH 3 SO 3 , LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiC(SO 2 ) At least one of CF 3 ) 3 or LiPO 2 F 2.
  • LiPF 6 can be selected as the lithium salt.
  • the non-aqueous solvent is not particularly limited as long as it can achieve the purpose of the present application.
  • the non-aqueous solvent may include at least one of carbonate compounds, carboxylate compounds, ether compounds, nitrile compounds, and other organic solvents.
  • the carbonate compound may include diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate Ester (MEC), Ethylene Carbonate (EC), Propylene Carbonate (PC), Butylene Carbonate (BC), Vinyl Ethylene Carbonate (VEC), Fluoroethylene Carbonate (FEC), Carbonic Acid 1 ,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate -Fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluorocarbonate- At least one of 2-methylethylene and trifluoromethylethylene carbonate.
  • the outer packaging in the present application can include an inner layer and an outer layer, and the inner layer is sealed with the bipolar current collector, so the material of the inner layer can include a polymer material, so as to achieve a good sealing effect; at the same time, the combination of the inner layer and the outer layer can Effectively protect the internal structure of electrochemical devices.
  • the material of the inner layer is not particularly limited, as long as the purpose of the application can be achieved, for example, the material of the inner layer includes polypropylene, polyester, p-hydroxybenzaldehyde, polyamide, polyphenylene ether, polyurethane at least one of etc.
  • the material of the outer layer is not particularly limited, as long as the purpose of the present application can be achieved.
  • the material of the outer layer includes at least one of aluminum foil, aluminum oxide layer, silicon nitride layer, and the like.
  • the thickness of the outer packaging is 60 to 200 ⁇ m, and the outer packaging of the above thickness can effectively protect the internal structure of the electrochemical device.
  • the sealing method includes one of hot pressing, glue sealing, and welding.
  • the hot pressing conditions are not particularly limited, as long as the purpose of the present application can be achieved.
  • the hot pressing temperature is 150-220°C
  • the hot pressing pressure is 0.1-0.6 MPa.
  • the present application also provides an electronic device comprising the electrochemical device provided by the present application.
  • the electronic device of the present application is not particularly limited, and it can be any electronic device known in the prior art.
  • display devices include, but are not limited to, notebook computers, pen-type computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, stereo headphones, video recorders, LCD televisions, portable Cleaners, portable CD players, mini discs, transceivers, electronic notepads, calculators, memory cards, portable recorders, radios, backup power supplies, motors, cars, motorcycles, power-assisted bicycles, bicycles, lighting equipment, toys, game consoles , clocks, power tools, flashlights, cameras, large household batteries and lithium-ion capacitors, etc.
  • the method for preparing the electrochemical device of the present application is not particularly limited, and any method known in the art can be used.
  • the present application can be prepared by the following preparation method:
  • the positive electrode active material and the solvent are prepared into a slurry, and stirred evenly.
  • the slurry is uniformly coated on the positive electrode sheet and dried to obtain a single-sided coated positive electrode sheet.
  • Electrodes assemblies stack the double-sided coated negative pole pieces, the separator, and the double-sided coated positive pole pieces in turn and fix the layers together for use.
  • Each electrode assembly includes a positive electrode tab and/or Or a negative electrode tab; repeating the above steps can obtain a plurality of electrode assemblies; the structure of the electrode assembly can be a winding structure or a laminated structure.
  • bipolar current collector coating positive electrode active material or negative electrode active material on one surface of bipolar current collector and drying, and drawing out a tab; or on two sides of bipolar current collector The positive electrode active material and the negative electrode active material are respectively coated on the surface and dried, and one tab or no tab is drawn out.
  • the thicknesses of the positive electrode active material and the negative electrode active material on the surface of the bipolar current collector are the same as the thicknesses on the above-mentioned positive electrode sheet and negative electrode sheet, respectively.
  • the outer packaging is installed in the assembly fixture, then the electrode assembly and the bipolar current collector are arranged at intervals, and the outer packaging is adjacent to the electrode assembly, and finally the assembled electrode assembly is obtained by sealing.
  • Liquid injection packaging inject electrolyte into each cavity of the assembled electrode assembly separately, and pull all the tabs of the electrode assembly out of the aluminum plastic film for subsequent processing.
  • the electrode assembly is connected in series: the positive electrode tab of one electrode assembly and the negative electrode tab of the other electrode assembly are welded and connected together to realize the series connection between the two electrode assemblies, and repeat the above steps to complete the assembly of the electrochemical device; or
  • Electrode assemblies are connected in series: the tabs of the bipolar current collector are connected in parallel with the tabs of the same polarity of the adjacent electrode assemblies, and then the positive tabs and the negative tabs of the two electrode assemblies are welded together. The series connection between the two electrode assemblies is realized, and the above steps are repeated to complete the assembly of the electrochemical device.
  • connection mode of the electrode assembly can be selected from the connection mode in (8.1) or the connection mode in (8.2) with reference to different embodiments in the specification.
  • the electrochemical device provided in this application may include two electrode assemblies, or may include three or more electrode assemblies.
  • preparation method of an electrochemical device containing two electrode assemblies or three or more electrode assemblies reference can be made to the above-mentioned preparation method of an electrochemical device. Electrochemical devices comprising three or more electrode assemblies are also within the scope of protection as defined in the claims of the present application.
  • the electrochemical device was allowed to stand at room temperature for 30 minutes, charged to a voltage of 4.4V (rated voltage) with a constant current at a charging rate of 0.05C, and then discharged to 3.0V at a rate of 0.05C. Repeat the above charging/ The discharge step was performed for 3 cycles to complete the formation of the electrochemical device to be tested. After completing the formation of the electrochemical device, the electrochemical device was charged at a constant current rate of 0.1C to a voltage of 4.4V, and then the electrochemical device was discharged to 3.0V at a discharge rate of 0.1C, and its discharge capacity was recorded, and then its 0.1C discharge rate was calculated.
  • Energy Density :
  • Lithium-ion battery self-discharge rate K Lithium-ion battery self-discharge rate K:
  • the test temperature is 25°C
  • a temperature probe is attached to the center of the surface of the cell to monitor the temperature of the main body of the cell, and foam is wrapped on the surface of the cell to weaken the heat exchange between the cell and the contact.
  • the test process is as follows: discharge with 0.2C constant current to 6V (series cells are 6V) or 3V (the single cell in the comparative example is 3V, the same below), then 05C cross-current charging to 8.4V or 4.2V, 02C charging to 8.9V Or 4.45V, let stand for 120min until the core temperature of the cell drops to room temperature 25°C. Use the same power ⁇ 15W to discharge, and monitor the temperature rise of the main body of the battery during the discharge process.
  • the electrochemical device to be tested was charged with constant current at a rate of 0.05C to a voltage of 4.45V (rated voltage of Comparative Example 1) or 8.90V (other comparative examples and all examples), followed by constant voltage charging to a current of 0.025C ( cut-off current), make the battery reach a fully charged state, and record the appearance of the electrochemical device before the test.
  • the electrochemical device was subjected to a piercing test in a 25-static °C environment. The diameter of the steel nail was 4mm, the piercing speed was 30mm/s, and the piercing position was located 15mm away from the edge of the positive electrode tab electrode assembly and 15mm away from the edge of the negative electrode tab electrode assembly. The test is carried out for 3.5 minutes or the surface temperature of the electrode assembly drops to 50 °C and the test is stopped. Take 10 cells as a group to observe the battery state during the test, and the battery does not burn or explode as the judgment standard.
  • the internal resistance meter was used for testing, and the excitation signal for the electrochemical device was 1KHz and 10mA.
  • the separator, the double-sided coated negative pole piece, the separator, and the double-sided coated positive pole piece are stacked in sequence to form a laminate, and then the four corners of the entire laminate structure are fixed for standby .
  • the electrode assembly A includes a positive electrode tab and a negative electrode tab
  • the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • Electrode assembly B Preparation of electrode assembly B: the double-sided coated negative pole piece, the separator, the double-sided coated positive pole piece, and the separator are stacked in sequence to form a laminate, and then the four corners of the entire laminate structure are fixed for future use.
  • the electrode assembly B includes a positive electrode tab and a negative electrode tab, and a polyethylene (PE) film with a thickness of 15 ⁇ m is selected as the separator.
  • PE polyethylene
  • bipolar current collectors CuAl composite current collectors with a thickness of 30 ⁇ m were used as bipolar current collectors.
  • the slurry of the negative electrode active material in step (1) was uniformly coated on one surface of the CuAl composite current collector, and dried at 110° C. to obtain a negative electrode active material layer with a thickness of 150 ⁇ m.
  • the slurry of the positive electrode active material in step (2) is uniformly coated on the other surface of the CuAl composite current collector, and dried at 90° C. to obtain a positive electrode active material layer with a thickness of 100 ⁇ m.
  • the bipolar current collector sealing area includes sealing material polypropylene (PP), and the thickness of the polypropylene sealing material is 20 ⁇ m and the width is 3 mm. Wherein, the sealing area is not coated with electrode active material.
  • Assembly of electrode assembly A place the punched aluminum-plastic film in the assembly jig with the pit face up, place the electrode assembly A in the pit with one side of the diaphragm facing up, and then place the bipolar current collector
  • the side provided with the positive electrode active material faces down and is placed on the electrode assembly A, so that the active material coating area corresponds to the positive electrode active material of the bipolar current collector and the active material of the negative electrode sheet is separated by a diaphragm, Apply external force to compress to obtain the assembled semi-finished product.
  • Assembly of electrode assembly B place the assembled semi-finished product in the assembly fixture, the side of the bipolar current collector with the negative electrode active material is facing up, the side of the diaphragm of the electrode assembly B is facing down, and placed on the bipolar current collector On the current collector, make the active material coating area correspond, apply external force to press, and then cover the electrode assembly B with the punched aluminum-plastic film pit face down, and heat the surrounding area by hot pressing to obtain the assembled electrode assembly.
  • the hot pressing temperature was 185° C.
  • the hot pressing pressure was 0.5 MPa
  • the width of the sealing area was 2 mm
  • the thickness of the sealing area was 0.03 mm.
  • Liquid injection packaging separately inject electrolyte into the two cavities of the assembled electrode assembly, and pull all the tabs of electrode assemblies A and B out of the aluminum plastic film for subsequent processing.
  • the electrode assembly is connected in series: the positive electrode tab of the electrode assembly A and the negative electrode tab of the electrode assembly B are welded and connected together by means of laser welding to realize the series connection between the electrode assembly A and B, and the battery is assembled.
  • the bipolar current collector is a composite bipolar current collector, that is, a film prepared by inserting a conductive carbon fiber into a PE matrix, and the rest are the same as those in Example 1.
  • the bipolar current collector is a stainless steel metal foil, and the rest are the same as in Example 1.
  • the bipolar current collector is a composite bipolar current collector, which is a film prepared by inserting a conductive carbon fiber into a PE matrix.
  • the thickness is 6 ⁇ m, and the rest is the same as that of Example 1.
  • the bipolar current collector is a composite bipolar current collector, which is a film prepared by inserting a conductive carbon fiber into a PE matrix.
  • the thickness is 100 ⁇ m, and the rest is the same as that of Example 1.
  • the bipolar current collector is a composite bipolar current collector, which is a film made by inserting conductive carbon fibers into a PE matrix, with a thickness of 55 ⁇ m, and the rest are the same as in Example 1.
  • Example 2 The rest is the same as Example 1, except that one tab is drawn out on the bipolar current collector. The tabs are used to detect the voltage of the electrochemical device.
  • the bipolar current collector is a composite bipolar current collector, which is a film prepared by inserting conductive carbon fibers into a PE matrix, and the rest are the same as those in Example 7.
  • the bipolar current collector is a stainless steel metal foil, and the rest are the same as in Example 7.
  • Electrode assembly B Preparation of electrode assembly B: the separator, the double-sided coated negative pole piece, the separator, the double-sided coated positive pole piece, and the separator are stacked in sequence to form a laminate, and then the four corners of the entire laminate structure are fixed. to spare.
  • the electrode assembly B includes a positive electrode tab and a negative electrode tab, and a polyethylene (PE) film with a thickness of 15 is selected as the separator.
  • PE polyethylene
  • Electrode assembly C the double-sided coated negative pole piece, the separator, the double-sided coated positive pole piece, and the separator are stacked in sequence to form a laminate, and then the four corners of the entire laminate structure are fixed for standby .
  • the electrode assembly C includes a positive electrode tab and a negative electrode tab, and a polyethylene (PE) film with a thickness of 15 is selected as the separator. .
  • PE polyethylene
  • bipolar current collector I and bipolar current collector II Preparation of bipolar current collector I and bipolar current collector II: The composite bipolar current collector was used as the bipolar current collector, and a thin film made of conductive carbon fiber was inserted into the PE matrix, and the thickness was 30 ⁇ m.
  • the slurry of the negative electrode active material in step (1) is uniformly coated on one surface of the composite bipolar current collector, and dried at 110° C. to obtain a negative electrode active material layer with a thickness of 150 ⁇ m.
  • the slurry of the positive electrode active material in step (2) is uniformly coated on the other surface of the composite bipolar current collector, and dried at 90° C. to obtain a positive electrode active material layer with a thickness of 100 ⁇ m.
  • the bipolar current collector sealing area includes sealing material polypropylene (PP), and the thickness of the polypropylene sealing material is 20 ⁇ m and the width is 3 mm. Wherein, the sealing area is not coated with electrode active material.
  • Assembly of electrode assembly A place the punched aluminum-plastic film in the assembly jig with the pit face up, place the electrode assembly A in the pit with one side of the diaphragm facing up, and then place the bipolar current collector One side of the positive electrode active material is placed on the electrode assembly A, so that the active material coating area is corresponding, and an external force is applied to press to obtain an assembled semi-finished product.
  • Assembling of electrode assembly C place the assembled semi-finished product in the assembly jig, make the side of the electrode assembly B close to the diaphragm of the negative electrode plate facing up, and place the side of the bipolar current collector II positive electrode active material down, place On the electrode assembly B, and then place the electrode assembly C with the diaphragm side down, and place it on the bipolar current collector II, so that the active material coating area corresponds, apply an external force to press, and then place the punched aluminum plastic film.
  • On the electrode assembly C heat-sealing the surrounding area by means of hot pressing to obtain an assembled electrode assembly.
  • the hot pressing temperature was 185° C.
  • the hot pressing pressure was 0.5 MPa
  • the width of the sealing area was 2 mm
  • the thickness of the sealing area was 0.03 mm. .
  • Liquid injection packaging separately inject electrolyte into the three cavities of the assembled electrode assembly, and pull all the tabs of the electrode assembly A, B, and C out of the aluminum plastic film for subsequent processing.
  • Electrode assemblies are connected in series: the positive electrode tab of electrode assembly A and the negative electrode tab of electrode assembly B are welded and connected together by laser welding to realize the series connection between electrode assemblies A and B, and connect the electrode assembly B The positive electrode tab and the negative electrode tab of the electrode assembly C are welded and connected together by laser welding to realize the series connection between the electrode assemblies B and C, and the battery assembly is completed.
  • Electrode assembly B Preparation of electrode assembly B: the separator, the double-sided coated negative pole piece, the separator, and the double-sided coated positive pole piece are stacked in sequence to form a laminate, and then the four corners of the entire laminate structure are fixed for standby .
  • the electrode assembly B includes a positive electrode tab and a negative electrode tab, and a polyethylene (PE) film with a thickness of 15 ⁇ m is selected as the separator.
  • PE polyethylene
  • bipolar current collector The composite bipolar current collector is used as the bipolar current collector, and the film is made by inserting conductive carbon fibers into the PE matrix, and the thickness is 30 ⁇ m.
  • the slurry of the positive electrode active material in step (2) is uniformly coated on one surface of the composite bipolar current collector, and dried at 90° C. to obtain a positive electrode active material layer with a thickness of 100 ⁇ m.
  • a tab is drawn from the bipolar current collector for backup.
  • the outer contour sealing area of the bipolar current collector includes the sealing material polypropylene (PP), the thickness of polypropylene is 20 ⁇ m, the coating width is 3 mm, and the electrode active material is not coated in the outer contour sealing area.
  • Assembly of electrode assembly A place the punched aluminum-plastic film in the assembly jig with the pit face up, place the electrode assembly A in the pit with one side of the diaphragm facing up, and then place the bipolar current collector The side provided with the positive active material is placed on the electrode assembly A with the positive active material facing down, so that the active material coating area is corresponding, and an assembled semi-finished product is obtained by applying external force to press.
  • Assembly of electrode assembly B place the assembled semi-finished product in the assembly jig, the side of the bipolar current collector without the electrode active material is facing up, and place the side of the electrode assembly B diaphragm down, and place it on the bipolar current collector.
  • On the fluid align with each edge of the semi-finished product, apply external force to press, and then cover the electrode assembly B with the punched aluminum-plastic film pit face down, and heat seal the surrounding by hot pressing to obtain the assembled electrode assembly.
  • the hot pressing temperature was 185° C.
  • the hot pressing pressure was 0.5 MPa
  • the width of the sealing area was 2 mm
  • the thickness of the sealing area was 0.03 mm.
  • Liquid injection packaging inject electrolyte into the two cavities of the assembled electrode assembly separately, and pull all the tabs of the electrode assemblies A and B and the tabs of the bipolar current collector out of the aluminum plastic film to prepare subsequent processing.
  • Electrode assemblies are connected in series: the positive tabs of electrode assembly A and the tabs of bipolar current collectors are welded together by laser welding, and then the negative tabs of electrode assembly B are connected to them by laser welding. Solder the connection to realize the series connection between the electrode assemblies A and B, and the battery assembly is completed.
  • the separator, the double-sided coated negative pole piece, the separator, and the double-sided coated positive pole piece are stacked in sequence to form a laminate, and then the four corners of the entire laminate structure are fixed for standby .
  • the electrode assembly A includes a positive electrode tab
  • the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • Electrode assembly B the single-sided coated negative pole piece, the separator, and the double-sided coated positive pole piece are stacked in sequence to form a laminate, and the uncoated side of the negative pole piece is placed outward, and then the entire laminate is placed The four corners of the structure are fixed for future use.
  • the electrode assembly B includes a negative electrode tab, and the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • PE polyethylene
  • bipolar current collector The composite bipolar current collector is used as the bipolar current collector, and the film is made by inserting conductive carbon fibers into the PE matrix, and the thickness is 30 ⁇ m.
  • the slurry of the positive electrode active material in step (2) is uniformly coated on one surface of the composite bipolar current collector, and dried at 90° C. to obtain a positive electrode active material layer with a thickness of 100 ⁇ m.
  • the outer contour sealing area of the bipolar current collector includes sealing material polypropylene (PP), the thickness of the sealing material polypropylene is 20 ⁇ m, the width is 3 mm, and the electrode active material is not coated in the outer contour sealing area.
  • Assembly of electrode assembly A place the punched aluminum-plastic film in the assembly jig with the pit face up, place the electrode assembly A in the pit with one side of the diaphragm facing up, and then place the bipolar current collector The side containing the positive active material is placed on the electrode assembly A with the side containing the positive active material facing down, so that the active material coating area is corresponding, and an assembled semi-finished product is obtained by applying an external force to press.
  • Assembly of electrode assembly B place the assembled semi-finished product in the assembly jig, with the side of the bipolar current collector without electrode active material facing up, and place the uncoated side of the negative electrode plate of electrode assembly B on the On the bipolar current collector, align it with each edge of the semi-finished product, apply external force to press, and then cover the electrode assembly B with the punched aluminum-plastic film pit face down, and heat the surrounding area by hot pressing to obtain the assembly.
  • the hot pressing temperature was 185° C.
  • the hot pressing pressure was 0.5 MPa
  • the width of the sealing area was 2 mm
  • the thickness of the sealing area was 0.03 mm.
  • Liquid injection packaging separately inject electrolyte into the two cavities of the assembled electrode assembly, and pull the positive electrode tab of electrode assembly A and the negative electrode tab of electrode assembly B out of the aluminum plastic film for subsequent processing.
  • Electrode assemblies are connected in series: the negative electrode tab of electrode assembly B is in contact with the uncoated surface of the bipolar current collector and forms an electrical connection to realize the series connection between electrode assemblies A and B, and the positive electrode tab of electrode assembly A and the electrode assembly are connected in series.
  • the negative tab of B is the output tab, and the battery is assembled.
  • bipolar current collector A composite bipolar current collector was used as the bipolar current collector, that is, a film made of PE matrix inserted into conductive carbon fibers, with a thickness of 30 ⁇ m.
  • the slurry of the positive electrode active material in step (2) is uniformly coated on one surface of the composite bipolar current collector, and dried at 90° C. to obtain a positive electrode active material layer with a thickness of 100 ⁇ m.
  • a tab is drawn from the bipolar current collector for backup.
  • the outer contour sealing area of the bipolar current collector includes sealing material polypropylene (PP), the thickness of the sealing material polypropylene is 20 ⁇ m, the width is 3 mm, and the electrode active material is not coated in the outer contour sealing area.
  • PP sealing material polypropylene
  • Assembly of electrode assembly A place the punched aluminum-plastic film in the assembly jig with the pit face up, place the electrode assembly A in the pit with one side of the diaphragm facing up, and then place the bipolar current collector The side containing the positive active material is placed on the electrode assembly A with the side containing the positive active material facing down, so that the active material coating area is corresponding, and an assembled semi-finished product is obtained by applying external force to press.
  • Assembly of electrode assembly B place the assembled semi-finished product in the assembly jig, with the side of the bipolar current collector without electrode active material facing up, and place the uncoated side of the negative electrode plate of electrode assembly B on the On the bipolar current collector, align it with each edge of the semi-finished product, apply external force to press, and then cover the electrode assembly B with the punched aluminum-plastic film pit face down, and heat the surrounding area by hot pressing to obtain the assembly.
  • electrode assembly the hot pressing temperature was 185° C.
  • the hot pressing pressure was 0.5 Mpa
  • the width of the sealing area was 2 mm
  • the thickness of the sealing area was 0.03 mm.
  • Liquid injection packaging separately inject electrolyte into the two cavities of the assembled electrode assembly, and pull all the tabs of electrode assemblies A and B out of the aluminum plastic film for subsequent processing.
  • Electrode assemblies are connected in series: the negative electrode tab of electrode assembly A and the positive electrode tab of electrode assembly B are welded and connected together by laser welding to realize the series connection between electrode assemblies A and B, and bipolar current collectors The tabs are used to monitor the voltage of the electrochemical device, and the battery is assembled.
  • the thickness of the bipolar current collector is 10 ⁇ m, and the rest is the same as that of Example 1.
  • the thickness of the bipolar current collector is 40 ⁇ m, and the rest is the same as that of Example 1.
  • the thickness of the bipolar current collector was 25 ⁇ m, and the rest was the same as that of Example 1.
  • each electrode assembly includes a positive electrode tab and a negative electrode tab
  • the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • bipolar current collector A copper-aluminum composite current collector with a thickness of 30 ⁇ m was used as the bipolar current collector.
  • the slurry of the negative electrode active material in step (1) was uniformly coated on one surface of the copper-aluminum composite current collector, and dried at 110° C. to obtain a negative electrode active material layer with a thickness of 150 ⁇ m.
  • the slurry of the positive electrode active material in step (2) is uniformly coated on the other surface of the copper-aluminum composite current collector, and dried at 90° C. to obtain a positive electrode active material layer with a thickness of 100 ⁇ m.
  • the bipolar current collector sealing area includes sealing material polypropylene (PP), and the thickness of the sealing material polypropylene is 20 ⁇ m and the width is 3 mm. Wherein, the sealing area is not coated with electrode active material.
  • Assembly of electrode assembly A place the punched aluminum-plastic film in the assembly jig with the pit face up, place the electrode assembly A in the pit, and then place the bipolar current collector on the side of the positive electrode active material face down, place it on the electrode assembly A, so that the active material coating area corresponds, and apply an external force to press to obtain an assembled semi-finished product.
  • Assembly of the electrode assembly B place the assembled semi-finished product in the assembly fixture, the side of the bipolar current collector containing the negative electrode active material is facing up, place the electrode assembly B on the bipolar current collector, and the electrode assembly B
  • the diaphragm close to the positive electrode plate is adjacent to the bipolar current collector, so that the active material coating area corresponds to the corresponding area, apply external force to press, and then cover the electrode assembly B with the punched aluminum-plastic film pit face down.
  • the surrounding area is heat-sealed by pressing to obtain an assembled electrode assembly.
  • the hot pressing temperature is 185° C.
  • the hot pressing pressure is 0.5 MPa
  • the width of the sealing area is 2 mm
  • the thickness of the sealing area is 0.03 mm.
  • Liquid injection packaging separately inject electrolyte into the two cavities of the assembled electrode assembly, and pull all the tabs of electrode assemblies A and B out of the aluminum plastic film for subsequent processing.
  • the bipolar current collector is replaced with a separator.
  • the separator adopts a composite PP structure, including two surface layers and an intermediate layer.
  • the surface layer has a melting point of 140 °C, and the middle is an ion insulating layer with a melting point of 165 °C.
  • the thickness of the separator is 50 ⁇ m. The rest are the same as in Example 1.
  • each electrode assembly contains a positive tab and a negative tab.
  • the separator is a polyethylene (PE) film with a thickness of 15 ⁇ m.
  • Liquid injection packaging package the electrode assemblies A and B with aluminum foil respectively, then seal the packaging around the package, inject electrolyte into the sealed cavities where the electrode assemblies A and B are located, and chemically form them into (0.02C constant temperature) Charge to 3.3V with current, then charge to 3.6V with 0.1C constant current), and then lead all the tabs of electrode assemblies A and B out of the aluminum plastic film.
  • the ending structure of electrode assembly A and the ending structure of electrode assembly B refer to the structures where electrode assembly A and electrode assembly B are adjacent to bipolar current collectors, respectively.
  • bipolar current collectors can improve the energy density by about 2% compared to insulating separators. Therefore, using bipolar current collectors as separators between series-connected electrode assemblies can not only improve the output voltage, reduce the charging temperature rise, but also improve the current density of the battery, which has very good industrial practicability.
  • the metal bipolar current collector is used, the battery charging temperature rise is small, which should be due to the stronger ability of the metal bipolar current collector to conduct heat to the outer package.

Abstract

一种电化学装置，包含双极性集流体，所述双极性集流体与外包装密封连接，在所述双极性集流体两侧形成各自独立的腔体，每个腔体中包含电极组件和电解液，所述双极性集流体的至少一个表面上包含电极活性材料，相邻的所述电极组件串联连接。本申请的电化学装置不仅可以提高电化学装置的安全性；而且双极性集流体表面的电极活性材料也参与电化学装置内的反应过程，使得电化学装置实现了高电压输出，同时具有较高的能量密度。

Description

一种电化学装置及电子装置 技术领域
本发明涉及电化学领域，特别是涉及一种电化学装置及包括所述电化学装置的电子装置。
背景技术
在现有锂离子电池体系中，由于正极材料和负极材料的电压差有限，电解液抗氧化还原能力有限等，电池的开路电压很难超过5V。但在电池实际使用中，需要用到超过5V电压的场景很多，如电动交通工具(EV)、电动工具(PT)、储能系统(ESS)等，即使在手机市场中，为了满足快充等需求，也需要电芯开路电压的提升。当前，一般采用多电池串联的方法来提高输出电压，但多电池串联存在诸多问题，如：电池个体间容量差异导致整体能量密度(Energy density)较低；串联用导线和接触电阻引入额外的电子电阻，导致发热浪费能量；电压越高需要单个电池数量越多，提高了电池管理的难度等。为了解决上述问题，高输出电压电池的概念被提出，其利用电池内部串联的方式实现单个电池的高电压输出，减小电池总产热，降低了使用过程中的升温幅度。
现有技术中的串联电池，是直接在同个包装袋内串联两个电池，其未对两串联电池做离子绝缘，如果电池电压升高，电解液在高电压条件下被分解，则会导致电池失效；另外，两电池间会因极片电压差发生内短路，也会导致电池失效。基于上述原因，目前提出的方案均只适用于固态电解质电池。然而主流锂电池为液态电解质，因此上述方案难以推广。
发明内容
本申请的目的是提供一种电化学装置，实现了高电压输出，同时具有较高的能量密度。
本申请第一方面提供了一种电化学装置，包含双极性集流体，所述双极性集流体与外包装密封连接，在所述双极性集流体两侧形成各自独立的腔体。每个腔体中封装有电极组件和电解液。所述双极性集流体的至少一个表面上设有电极活性材料。相邻腔体中的所述电极组件串联连接。
在本申请第一方面的一些实施方式中，所述腔体是密封腔体。
在本申请第一方面的一些实施方式中，所述双极性集流体的第一表面上设有电极活性材料。所述电极活性材料的极性与相邻的电极组件的最外层电极极片极性相反。所述最外层电极极片与所述双极性集流体之间设有隔膜。所述双极性集流体的第二表面与相邻的电 极组件电绝缘。
在本申请第一方面的一些实施方式中，所述双极性集流体上设置极耳，所述极耳与所述第一表面相邻的电极组件中相同极性的极耳并联连接。
在本申请的一些实施方式中，所述双极性集流体的厚度为6μm至100μm，优选为10μm至55μm。
在本申请一些实施方式中，所述双极性集流体的厚度为10μm至40μm，优选为20μm至30μm。
在本申请第一方面的一些实施方式中，所述双极性集流体的第一表面上设有电极活性材料，所述电极活性材料与相邻的电极组件的最外层电极极片极性相反，所述双极性集流体的第二表面与相邻的电极组件的最外层电极极片的集流体电连接，所述第二表面相邻的电极极片的极性与所述第一表面上的电极活性材料的极性相反。
在本申请第一方面的一些实施方式中，所述双极性集流体的两个表面分别设有不同极性的电极活性材料，与每个表面相邻的电极组件的最外层电极极片与该表面上的电极活性材料极性不同，所述电极组件的最外层电极极片与所述双极性集流体之间设有隔膜。
在本申请第一方面的一些实施方式中，所述电化学装置设置有极性相反的两个极耳，所述电化学装置的电极组件在所述两个极耳之间串联连接。
在本申请第一方面的一些实施方式中，所述电极组件各自设置有极性相反的两个极耳，其中一个极耳与相邻电极组件的极性相反的极耳串联连接。
在本申请第一方面的一些实施方式中，所述双极性集流体上还设置有一个极耳，用于检测其两侧的电极组件的运行状态。
在本申请第一方面的一些实施方式中，所述双极性集流体上还设置有极耳，所述极耳与将所述双极性集流体两侧的电极组件相互串联的极耳连接。
本申请第二方面提供了一种电子装置，其包含本申请第一方所提供的电化学装置。
本申请提供的电化学装置，双极性集流体不仅具有物理隔离作用，将双极性集流体两侧的电极组件完全隔离形成独立的密封腔体，保障了电化学装置的正常工作以及提高了电化学装置的安全性；而且双极性集流体表面的电极活性材料也参与电化学装置内的电化学反应过程，使得电化学装置实现了高电压输出，同时具有较高的能量密度。同时，双极性集流体与外包装密封连接，因此可以采用液态电解质，从而能够满足市场的需求。
附图说明
为了更清楚地说明本发明实施例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，并非是全部实施例。
图1为本申请一种实施方式中的电化学装置示意图；
图2为本申请一种实施方式中的电化学装置内部结构剖面局部示意图；
图3为本申请另一种实施方式中的电化学装置内部结构剖面局部示意图；
图4为本申请另一种实施方式中的电化学装置示意图；
图5为本申请另一种实施方式中的电化学装置内部结构剖面局部示意图；
图6为本申请一种实施方式中的双极性集流体结构示意图。
附图标记：
1、双极性集流体；2、电极组件；201、电极组件；202、电极组件；3、外包装；4、双极性集流体极耳；5、正极极耳；6、负极极耳；7、正极活性材料；8、负极活性材料；9、隔膜；10、正极集流体；11、负极集流体；12、密封区域。
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，以下参照附图并举实施例，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。
本申请的电化学装置可以是使用本领域技术人员所熟知的任何电化学装置，例如锂离子电池、钠离子电池、镁离子电池、超级电容器等，以下以锂离子电池为例进行说明。本领域技术人员应当理解，以下说明仅为举例说明，并不限定本申请的保护范围。
本申请提供一种电化学装置，其包含双极性集流体，所述双极性集流体与外包装密封连接，在所述双极性集流体两侧形成各自独立的密封腔体，每个密封腔体中封装有电极组件和电解液，所述双极性集流体的至少一个表面上设有电极活性材料，相邻的密封腔体中的电极组件串联连接。
图1示出了本申请的一种实施方式，包含一个双极性集流体1，所述双极性集流体1与外包装3密封连接，在所述双极性集流体1两侧形成各自独立的腔体，每个腔体中包含一个电极组件2和电解液，所述双极性集流体1的至少一个表面上包含电极活性材料，相邻的所述电极组件2串联连接。
所述腔体为密封腔体。
本申请中的双极性集流体是指两面可以同时涂覆不同极性活性物质的集流体，其同时具有正极集流体和负极集流体的特性。
在本申请的一些实施方式中，所述双极性集流体与外包装密封连接，在双极性集流体的两侧形成各自独立的密封腔体，双极性集流体两侧电极组件和电解液被完全分隔，不仅可以保障两侧电极组件的正常工作，而且良好的密封性也有利于提高了电化学装置的安全性。此外，双极性集流体具有电子导通且离子绝缘的特性，可以避免发生内短路、电解液高压分解以及电极组件内短路。双极性集流体的至少一个表面上设有电极活性材料，所述电极活性材料的存在使得双极性集流体可以参与电化学装置的电化学反应，可以有效提高电化学装置的能量密度。相邻的电极组件串联连接则可以实现高电压输出，从而可以满足现有市场的需求。
在本申请的一些实施方式中，所述双极性集流体的第一表面上设有电极活性材料，所述电极活性材料与相邻的电极组件的最外层电极极片极性相反，所述最外层电极极片与所述双极性集流体之间设有隔膜；所述双极性集流体的第二表面与相邻的电极组件电绝缘。在该实施方式中，所述双极性集流体的第一表面与相邻电极组件的最外层电极极片构成电化学单元，参与电化学装置的充放电过程，提高了电化学装置的能量密度。
在本申请的一些实施方式中，所述双极性集流体上设置极耳，所述极耳与所述第一表面相邻的电极组件中极性相同的极耳并联连接。在该实施方式中，所述极耳并联后与所述双极性集流体第二表面相邻的电极组件串联连接，从而提供高输出电压。
图2示出了本申请的一个实施方式，所述双极性集流体1的a面上设置有正极活性材料7，b面没有电极活性材料，与a面相邻的电极组件201的最外层设置有负极活性材料8，与b面相邻的电极组件202的最外层设置有隔膜9，双极性集流体1上设置极耳4(如图1所示)，双极性集流体1的极耳4与双极性集流体a面相邻一侧电极组件201的正极极耳连接，形成并联，再与电极组件202的负极极耳连接，形成串联，实现电极组件201和202的串联。本领域技术人员可以理解，所述双极性集流体的a面上的正极活性材料也可以为负极活性材料，此时，与a面相邻的电极组件201的最外层包含正极活性材料，双极性集流体的极耳与电极组件201的负极极耳连接，形成并联，再与电极组件202的正极极耳连接，形成串联。
在本申请的一些实施方式中，所述双极性集流体的第一表面上设置有电极活性材料， 所述电极活性材料与相邻的电极组件的最外层电极极片的极性相反，所述最外层电极极片与所述双极性集流体之间设有隔膜；所述双极性集流体的第二表面与相邻的电极组件的最外层电极极片的集电体电连接，所述第二表面相邻的电极组件的最外层电极极片的极性与所述第一表面上的电极活性材料的极性相反。
在本申请的一些实施方式中，所述双极性集流体可以不引出极耳，此时，双极性集流体两侧的电极组件直接通过双极性集流体实现内部串联，所述电化学装置可以只引出两个极性相反的极耳，其中所有的电极组件在两个极性相反的极耳之间通过双极性集流体串联连接。
在本申请的一些实施方式中，所述双极性集流体也可以引出一个极耳，该极耳与双极性集流体设置有电极活性材料一侧的电极组件上相同极性极耳连接，形成并联，然后与另一侧的电极组件上相反极性的极耳连接，形成串联，此时，两个电极组件中间可以通过双极性集流体内部串联并通过极耳外部串联。另外，双极性集流体的极耳也可以不与电极组件的极耳相连，仅用于监控电化学装置的电压。
图3示出本申请的一个实施方式，所述双极性集流的a面上包含负极活性材料8，双极性集流体1的b面没有电极活性材料，与双极性集流体1的a面相邻的电极组件201的最外层设置有正极活性材料7，与双极性集流体1的b面相邻的电极组件202的最外层为正极集流体10，正极集流体10与双极性集流体1的b面形成电连接。电极组件201和电极组件202可以直接通过双极性集流体1实现串联，引出电极组件201的正极极耳和电极组件202的负极极耳，作为电化学装置的充放电极耳。在本申请的一些实施方式中，双极性集流体上设置一个极耳，该极耳与电极组件201的负极极耳连接，形成并联，然后与电极组件202的正极极耳连接，形成串联，此时，两个电极组件中间既通过双极性集流体内部串联并通过极耳外部串联。另外，双极性集流体上的极耳也可以不与电极组件的极耳相连，仅用于监控电化学装置的电压。
本领域技术人员可以理解，所述双极性集流体的a面上的负极活性材料也可以为正极活性材料，此时，与a面相邻的电极组件201的最外层设置有负极活性材料，与双极性集流体1的b面相邻的电极组件202的最外层为负极集流体，电极组件201和电极组件202可以直接通过双极性集流体1实现串联。
在本申请的一些实施方式中，所述双极性集流体的两个表面分别设有不同极性的电极活性材料，与每个表面相邻的电极组件的最外层电极极片与该表面上的电极活性材料极性 不同，所述电极组件的最外层电极极片与双极性集流体之间设有隔膜。所述双极性集流体的两个表面分别设有极性不同的电极活性材料，两个表面分别与相邻的电极组件的最外层电极极片形成电化学单元，进一步提高电池的能量密度。
双极性集流体两侧的电极组件可以直接通过双极性集流体实现内部串联，也可以通过双极性集流体和两个极性相反的极耳同时实现内部串联和外部串联。
图5示出了本申请的一个实施方式，所述双极性集流体1的a面上设有正极活性材料7，双极性集流体1的b面上设有负极活性材料8，与双极性集流体1的a面相邻的电极组件201的最外层电极极片包含负极活性材料8，与双极性集流体1的b面相邻的电极组件202的最外层电极极片包含正极活性材料7。电极组件201和电极组件202可以直接通过双极性集流体1实现内部串联，引出电极组件201的负极极耳和电极组件202的正极极耳为电化学装置的输出极耳。
在本申请的一些实施方式中，所述双极性集流体的a面上设有正极活性材料，b面上设有负极活性材料，与a面相邻的电极组件201的最外层电极极片包含负极活性材料，与b面相邻的电极组件202的最外层电极极片包含正极活性材料。引出电极组件201和202的所有极耳，电极组件201的正极极耳和电极组件202的负极极耳串联连接，引出电极组件201和202不仅通过双极性集流体实现了内部串联，而且通过极耳实现了外部串联，电极组件201的负极极耳与电极组件202的正极极耳为电化学装置的输出极耳，如图4所示。
在本申请的一些实施方式中，所述双极性集流体的两个表面分别设有极性不同的电极活性材料，所述双极性集流体上设置一个极耳，所述极耳可以用于监控电化学装置的电压，或者将所述极耳绝缘包覆。该极耳也可以与将双极性集流体两侧的电极组件串联的极耳相连接。
在本申请的一些实施方式中，对双极性集流体没有特别限制，只要其两个表面上可以设置极性不同的电极活性物质即可。通常，双极性集流体需要具有抗氧化还原性能，能够在电解液中稳定存在，例如所述双极性集流体包括金属双极性集流体或复合双极性集流体。所述金属双极性集流体包括铜铝复合集流体、不锈钢(，Ni、Ti、Ag、Au、Pt等集流体中的至少一种。
所述复合双极性集流体没有特别限制，例如，一种复合双极性集流体包括金属和聚合物，其中，金属设置于聚合物的表面上，且两个表面的上的金属可以相同或不同，两个表面上的金属之间电连接。在本申请中，所述金属没有特别限制，只要能实现本申请的目的 即可，例如，金属包括Cu、Al、Ni、Ti、Ag、Au、Pt等中的两种。在本申请中，所述聚合物没有特别限制，只要能实现本申请的目的即可，例如，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)、有机硅树脂、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、聚砜或上述物质衍生物中的至少一种。
另外一种复合双极性集流体包括一维或二维导电材料和聚合物，导电材料以一定角度(例如0°至30°)嵌入聚合物，实现厚度方向的导电性能。其中所述导电材料包括碳材料或金属材料中的至少一种。所述碳材料包括单壁碳纳米管、多壁碳纳米管、导电碳纤维、导电炭黑、富勒烯、导电石墨或石墨烯中的至少一种。所述金属材料包括Ni、Ti、Ag、Au、Pt或不锈钢及其合金中的至少一种。所述聚合物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)、有机硅树脂、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、聚砜或上述物质衍生物中的至少一种。
在本申请的一些实施方式中，所述双极性集流体的厚度为6μm至100μm，优选为10μm至55μm。在本申请一些实施方式中，所述双极性集流体的厚度为10μm至40μm，优选为20μm至30μm。所述双极性集流体不仅具有离子绝缘的特性，同时也应具有一定的机械强度。因此，所述双极性集流体太薄则机械强度较差，容易造成破损影响电化学装置的性能甚至安全性。太厚则会影响电子的传导，并降低电化学装置的能量密度，使得电化学装置的性能发挥受到限制。所述双极性集流体在Z方向的电子电阻率为1×10 -11至30Ω·cm，优选为1×10 -5至5Ω·cm，更优选为0.01至0.10Ω·cm。
当所述双极性集流体表面的电极活性物质为正极活性材料时，正极活性材料的厚度为30至120μm；当所述双极性集流体表面的电极活性物质为负极活性材料时，负极活性材料的厚度为30至120μm。所述双极性集流体的表面上包含电极活性材料，可以参与电化学装置内的反应过程，不仅可以提高输出电压，同时也可以提高电化学装置的能量密度。在本申请中，电极活性材料的厚度太薄，则会受产品颗粒度影响涂层表面不平整，且所涂物 质所能发挥的能量较低，电极活性材料的厚度太厚，则会影响电芯的电化学反应活性。因此，选择上述厚度的电极活性材料更有利于实现高电压输出，同时具有较高的能量密度。
在本申请的一些实施方式中，如图6所示，所述双极性集流体1还包括密封区域12，所述密封区域12位于所述双极性集流体1的四周边缘，所述密封区域还包含密封材料，所述密封材料包括聚丙烯、酸酐改性聚丙烯、聚乙烯、乙烯-醋酸乙烯共聚物、乙烯-丙烯酸乙酯共聚物、乙烯-丙烯酸共聚物、乙烯-乙烯醇共聚物、聚氯乙烯、聚苯乙烯、聚醚腈、聚氨酯、聚酰胺、聚酯、非晶态α-烯烃共聚物及其衍生物中的至少一种。选用上述密封材料可以更有效地与外包装进行密封连接，从而有利于提高电化学装置的安全性。
在本申请中，对于双极性集流体与外包装之间的密封方法没有特别限制，可以采用本领域公知的任何密封方法，例如，一种典型的方法是将双极性集流体四周边缘设置密封材料与外包装进行热压封印，在密封材料与外包装的接触区域形成密封区域。在热压封印过程中，密封区域内的高分子材料与外包装内层的高分子材料融合。在本申请中，所述密封区域的尺寸没有特别限制，只要能实现本申请的目的即可。例如，所述密封区域的封印厚度T(单位：mm)与封印宽度W(单位：mm)满足0.01≤T/W≤0.05。T/W的比值在上述范围内，可以保证电池的密封良好，提高电池的使用寿命。当T/W过小时，可能封印厚度不足，密封效果不好，导致电池的环境稳定性降低，例如，环境中的水汽容易渗透到电池内部，导致电池内水分含量增大，电解质分解，降低电池的使用寿命；T/W的比值过大，可能封印宽度W太小，同样存在密封效果不好，导致电池的环境稳定性降低，例如，环境中的水汽容易渗透到电池内部，导致电池内水分含量增大，电解质分解等问题，降低电池的使用寿命。在本申请中，封印厚度和封印宽度没有特别限定，只要能够实现本发明目的即可，例如封印宽度优选为1mm至7mm。
在本申请的封印过程中，外包装中的高分子材料与密封材料中的高分子材料经过热压封印在一起。因此，封印厚度包括密封材料中高分子材料与外包装内层高分子材料融合之后的厚度。封印宽度是指热压封印后密封材料中的高分子材料与外包装内层高分子材料结合在一起形成的密封区域的宽度。
在本申请的一些实施方式中，所述电解液包括凝胶态、固态和液态中的一种。在本申请中，所述电解液没有特别限定，只要能实现本申请的目的即可。在本申请的一些实施方式中，所述电极组件的结构包括卷绕结构或叠片结构。串联连接的电池组件可以具有相同的结构或不同的结构。
在本申请的一些实施方式中，所述电极组件的结构为卷绕结构，电极组件包含单极耳或多极耳。所述电极组件包含单极耳，是从正极极片和负极极片上分别引出一个正极极耳和一个负极极耳。所述电极组件包含多极耳，可以是从每一圈正极极片和负极极片上分别引出一个正极极耳和一个负极极耳，也可以是从两圈或多圈正极极片和负极极片上分别引出一个正极极耳和一个负极极耳，最终一个卷绕结构的电极组件包含多组正极极耳和负极极耳，然后经转接焊转极耳引线。
在本申请的一些实施方式中，所述电极组件的结构为叠片结构，电极组件包含多极耳，可以是从每一层正极极片和负极极片上分别引出一个正极极耳和一个负极极耳，最终一个叠片结构的电极组件包含多组正极极耳和负极极耳，然后经转接焊转极耳引线。
在本申请中，所述焊接的方式没有特别限定，只要能实现本申请的目的即可。例如，激光焊、超声焊或电阻焊等。
在本申请的一些实施方式中，所述串联极耳在所述电化学装置厚度方向上堆叠分布或错位分布。本申请对极耳的分布没有特别限制，只要能实现本申请的目的即可。在实际应用中，极耳的分布可以根据需求进行调整。
本申请中所说的电极组件可以是包含正极极片、负极极片和隔膜的电极组件，并以上述电极组件为例进行说明。本领域技术人员应当理解，以下说明仅为举例说明，并不限定本申请的保护范围。
在本申请的一些实施方式中，正极极片没有特别限制，只要能够实现本申请目的即可。例如，所述正极极片通常包含正极集流体和正极活性材料。在本申请中，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，例如铜箔、铝箔、铝合金箔以及复合集电体等。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，例如，所述正极活性物质包括镍钴锰酸锂、镍钴铝酸锂、磷酸铁锂、钴酸锂、锰酸锂或磷酸锰铁锂中的至少一种。在本申请中，正极集流体和正极活性材料的厚度没有特别限制，只要能够实现本申请目的即可。例如，正极集流体的厚度为8-12μm，正极活性材料的厚度为30-120μm。
在本申请的一些优选实施方式中，所述正极极片还可以包含导电层，所述导电层位于正极集流体和正极活性材料层之间。所述导电层的组成没有特别限制，可以是本领域常用的导电层。所述导电层包括导电剂和粘接剂。
在本申请的一些实施方式中，负极极片没有特别限制，只要能够实现本申请目的即可。 例如，所述负极极片通常包含负极集流体和负极活性材料。在本申请中，所述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电体等。所述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、硅、硅碳、硅氧化合物、软碳、硬碳、钛酸锂或钛酸铌中的至少一种。在本申请中，负极集流体和负极活性材料的厚度没有特别限制，只要能够实现本申请目的即可。例如，负极集流体的厚度为6-10μm，负极活性材料的厚度为30-120μm。
在本申请的一些优选实施方式中，所述负极极片还可以包含导电层，所述导电层位于负极集流体和负极活性材料层之间。所述导电层的组成没有特别限制，可以是本领域常用的导电层。所述导电层包括导电剂和粘接剂。
上述所述导电剂没有特别限制，可以使用本领域公知的任何导电剂，只要能实现本申请目的即可。例如，导电剂可以包括导电炭黑(Super P)、碳纳米管(CNTs)、碳纤维或石墨烯等中的至少一种。上述所述粘接剂没有特别限制，可以使用本领域公知的任何粘接剂，只要能实现本申请目的即可。例如，粘接剂可以包括丁苯橡胶(SBR)、聚乙烯醇(PVA)、聚四氟乙烯(PTFE)或羧甲基纤维素钠(CMC-Na)等中的至少一种。。
在本申请的一些实施方式中，隔膜没有特别限制，只要能够实现本申请目的即可。例如，隔膜的厚度可以为5-15μm，隔膜可以包括对本申请的电解液稳定的材料形成的聚合物或无机物等。在本申请中，隔膜也可以称为隔离膜。
例如，隔膜可以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，基材层的材料可以包括聚乙烯、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。
本申请中所说的极耳是指从正极极片或者负极极片上引出来的金属导体，用于串联连接或并联连接电化学装置的其它部分。正极极耳是从正极极片上引出，负极极耳是从负极极片上引出。
在本申请所说的电解液可以包含锂盐和非水溶剂。在本申请中，所述锂盐没有特别限制，可以使用本领域公知的任何锂盐，只要能实现本申请的目的即可。例如，锂盐可以包括LiPF 6、LiBF 4、LiAsF 6、LiClO 4、LiB(C 6H 5) 4、LiCH 3SO 3、LiCF 3SO 3、LiN(SO 2CF 3) 2、LiC(SO 2CF 3) 3或LiPO 2F 2中的至少一种。例如，锂盐可选用LiPF 6。在本申请中，所述非水溶剂没有特别限定，只要能实现本申请的目的即可。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、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、碳酸三氟甲基亚乙酯中的至少一种。
本申请对外包装没有特别限制，只要能实现本申请的目的即可。例如，外包装可以包含内层和外层，内层与双极性集流体密封连接，因此内层的材料可以包括高分子材料，从而实现良好的密封效果；同时内层和外层的结合能够有效得保护电化学装置的内部结构。在本申请中，所述内层材料没有特别限制，只要能实现本申请的目的即可，例如，内层的材料包括聚丙烯、聚酯、对羟基苯甲醛、聚酰胺、聚苯醚、聚氨酯等中的至少一种。在本申请中，所述外层材料没有特别限制，只要能实现本申请的目的即可，例如，外层的材料包括铝箔、氧化铝层、氮化硅层等中的至少一种。
在本申请对外包装的厚度没有特殊限制，只要能实现本申请的目的即可。例如，外包装的厚度为60至200μm，上述厚度的外包装可以有效保护电化学装置的内部结构。
本申请对双极性集流体与外包装的密封连接方式没有特别限制，只要能实现本申请的目的即可。例如，密封方式包括热压、胶水胶封、焊接中的一种。在本申请中，所述热压 条件没有特别限定，只要能实现本申请的目的即可，例如针对聚丙烯内层材料，热压温度为150-220℃，热压压力为0.1-0.6MPa。
本申请还提供一种电子装置，其包含本申请提供的电化学装置。本申请的电子装置没有特别限定，其可以是现有技术中已知的任何电子装置。例如，显示装置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、家庭用大型蓄电池和锂离子电容器等。
制备本申请的电化学装置的方法没有特别限制，可以采用本领域公知的任何方法，例如，在一实施方式中，本申请可以采用如下制备方法制备：
(1)负极极片的制备：将负极活性材料和溶剂调配成浆料，并搅拌均匀。将浆料均匀涂覆在负极极片上并烘干，得到单面涂覆的负极极片。在负极极片的另一个表面上重复以上步骤，得到双面涂覆的负极极片。然后，将负极极片裁切待用。
(2)正极极片的制备：将正极活性材料和溶剂调配成浆料，并搅拌均匀。将浆料均匀涂覆在正极片上并烘干，得到单面涂覆的正极极片。在正极极片的另一个表面上重复以上步骤，得到双面涂覆的正极极片。然后，将正极极片裁切待用。
(3)电解液的制备：将锂盐和非水溶剂混合并搅拌均匀，得到含有锂盐的电解液。
(4)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叠好并将各层固定在一起以备用，每个电极组件包含一个正极极耳和/或一个负极极耳；重复上述步骤则可得到多个电极组件；电极组件的结构可以是卷绕结构或叠片结构。
(5)双极性集流体的制备：在双极性集流体的一个表面上涂覆正极活性材料或负极活性材料并烘干，并引出一个极耳；或者在双极性集流体的两个表面上分别涂覆正极活性材料和负极活性材料并烘干，引出一个极耳或不引出极耳。其中，双极性集流体表面上的正极活性材料和负极活性材料的厚度与分别与上述正极极片和负极极片上的厚度相同。
(6)电极组件的组装：将外包装置于组装夹具内，然后将电极组件与双极性集流体间隔设置，且外包装与电极组件相邻，最后进行密封得到组装电极组件。
(7)注液封装：分别给组装电极组件的每个腔体单独注入电解液，并将电极组件的所有极耳引出铝塑膜外，以备后续加工。
(8.1)电极组件串联连接：将一个电极组件的正极极耳和另一个电极组件的负极极耳焊接连接在一起，实现两个电极组件之间的串联，重复上述步骤完成电化学装置的组装；或
(8.2)电极组件串联连接：将双极性集流体的极耳与相邻电极组件相同极性的极耳并联，然后再将两个电极组件的正极极耳和负极极耳焊接连接在一起，实现两个电极组件之间的串联，重复上述步骤完成电化学装置的组装。
上述制备过程中，电极组件的连接方式参照说明书中不同的实施方式可以选择(8.1)中的连接方式或(8.2)中的连接方式。
本申请提供的电化学装置中可以包含两个电极组件，也可以包含三个及以上电极组件。含有两个电极组件或三个及以上电极组件的电化学装置的制备方法均可参照上述电化学装置的制备方法。包含三个或多个电极组件的电化学装置同样在本申请权利要求所定义的保护范围内。
本申请中所用的术语一般为本领域技术人员常用的术语，如果与常用术语不一致，以本申请中的术语为准。在本申请中，如果没有特别说明，“％”、“份”均以重量为基准。
测试方法：
电池能量密度
将电化学装置在常温下静置30分钟，以0.05C充电速率恒流充电至电压至4.4V(额定电压)，随后之后再以0.05C倍率将电化学装置放电至3.0V，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4.4V，随后以0.1C放电倍率将电化学装置放电至3.0V，纪录其放电容量，随后计算其0.1C放电时的能量密度：
能量密度(Wh/L)＝放电容量(Wh)/电化学装置体积尺寸(L)
锂离子电池自放电速率K：
将锂离子电池以0.5C的电流放电至3.0V，静置5min，接着将锂离子电池以0.5C的电流恒定电流充电至3.85V，然后以3.85V的恒定电压充电至电流为0.05C，在25℃±5℃的环境中静置两天，测试并记录此时的电压OCV1。接着，将锂离子电池继续在25℃±5℃的环境静置两天，测试并记录此时的电压OCV2，通过如下公式获得K值：K(mV/h)＝(OCV2-OCV1)/48h-OCV1。
放电升温：
测试温度为25℃，在电芯表面中央粘结一温度探头，监控电芯主体温度，并在电芯表面包裹泡棉，削弱电芯与接触物之间的热交换。测试过程如下：以0.2C恒流放电到6V(串联电芯为6V)或3V(对比例中单个电芯3V，以下相同)，后05C横流充至8.4V或4.2V，02C充电至8.9V或4.45V，静置120min至电芯中心温度降低至常温25℃。使用相同功率～15W放电，监控电芯主体放电过程温升。
穿钉测试：
将待测的电化学装置以0.05C的倍率恒流充电至电压为4.45V(对比例1额定电压)或8.90V(其他对比例及所有实施例)，随后恒压充电至电流为0.025C(截止电流)，使电池达到满充状态，记录测试前电化学装置外观。在25止电℃环境中对电化学装置进行穿钉测试，钢钉直径4mm，穿刺速度30mm/s，穿钉位置分别位于距离正极极耳电极组件边缘15mm处和距离负极极耳电极组件边缘15mm处，测试进行3.5min或电极组件表面温度降到50℃以后停止测试，以10个电芯为一组，观察测试过程中电池状态，以电池不燃烧，不爆炸为判定标准。
交流阻抗测试：
采用内阻仪进行测试，对电化学装置的激励信号为1KHz、10mA。
实施例1：
(1)负极极片的制备：将负极活性材料人造石墨、导电炭黑(Super P)、丁苯橡胶(SBR)按照重量比96:1.5:2.5进行混合，加入去离子水作为溶剂，调配成固含量为70wt％的浆料，并搅拌均匀。将浆料均匀涂覆在厚度为10μm的负极集流体铜箔的一个表面上，110℃条件下烘干，得到涂层厚度为150μm的单面涂覆有负极活性材料层的负极极片。在该负极极片的另一个表面上重复以上步骤，得到双面涂覆有负极活性材料层的负极极片。然后，将负极极片裁切成41mm×61mm的规格待用。
(2)正极极片的制备：将正极活性材料钴酸锂(LiCoO 2)、导电炭黑(Super P)、聚偏二氟乙烯(PVDF)按照重量比97.5:1.0:1.5进行混合，加入N-甲基吡咯烷酮(NMP)作为溶剂，调配成固含量为75wt％的浆料，并搅拌均匀。将浆料均匀涂覆在厚度为12μm的正极集流体铝箔的一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm的正极极片。在正极集流体铝箔的另一个表面上，重复以上步骤，得到双面涂覆有正极活性材 料层的正极极片。然后，将正极极片裁切成38mm×58mm的规格待用。
(3)电解液的制备：在干燥氩气气氛中，首先将有机溶剂碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)和碳酸二乙酯(DEC)以质量比EC:EMC:DEC＝30:50:20混合，然后向有机溶剂中加入锂盐六氟磷酸锂(LiPF 6)溶解并混合均匀，得到锂盐的浓度为1.15mol/L的电解液。
(4)电极组件A的制备：将隔膜、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，然后将整个叠片结构的四个角固定好以备用。其中，电极组件A包含一个正极极耳和一个负极极耳，隔膜选用厚度15μm的聚乙烯(PE)膜。
(5)电极组件B的制备：将双面涂覆负极极片、隔膜、双面涂覆正极极片、隔膜依次层叠设置组成叠片，然后将整个叠片结构的四个角固定好以备用。其中，电极组件B包含一个正极极耳和一个负极极耳，隔膜选用厚度15μm的聚乙烯(PE)膜。
(6)双极性集流体的制备：采用厚度为30μm的CuAl复合集流体作为双极性集流体。将步骤(1)中负极活性材料的浆料均匀涂覆在CuAl复合集流体的一个表面上，110℃条件下烘干，得到负极活性材料层厚度为150μm。再将步骤(2)中正极活性材料的浆料均匀涂覆在CuAl复合集流体的另一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm。其中，双极性集流体密封区域包含密封材料聚丙烯(PP)，聚丙烯密封材料的厚度为20μm，宽度为3mm。其中，密封区域不涂覆电极活性材料。
(7)电极组件A的组装：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，且隔膜一侧朝上，然后将双极性集流体设置有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，双极性集流体的正极活性材料与负极极片的活性材料之间由隔膜隔开，施加外力压紧得到组装半成品。
(8)电极组件B的组装：将组装半成品置于组装夹具内，双极性集流体设置有负极活性材料的一面朝上，将电极组件B的隔膜一侧朝下，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。其中，热压温度为185℃，热压压力为0.5MPa，密封区域的宽度为2mm，密封区域的厚度为0.03mm。
(9)注液封装：分别给组装电极组件的两个腔体单独注入电解液，并将电极组件A和B的所有极耳引出铝塑膜外，以备后续加工。
(10)电极组件串联连接：将电极组件A的正极极耳和电极组件B的负极极耳通过激 光焊的方式焊接连接在一起，实现电极组件A和B之间的串联，电池组装完成。
实施例2
双极性集流体为复合双极性集流体，即PE基体插入导电碳纤维所制得的薄膜，其余与实施例1相同。
实施例3
双极性集流体为不锈钢金属箔，其余与实施例1相同。
实施例4
双极性集流体为复合双极性集流体，为PE基体插入导电碳纤维所制得的薄膜，厚度为6μm，其余与实施例1相同。
实施例5
双极性集流体为复合双极性集流体，为PE基体插入导电碳纤维所制得的薄膜，厚度为100μm，其余与实施例1相同。
实施例6
双极性集流体为复合双极性集流体，为PE基体插入导电碳纤维所制薄膜，厚度为55μm，其余与实施例1相同。
实施例7
除了在双极性集流体上引出一个极耳以外，其余与实施例1相同。该极耳用于检测电化学装置的电压。
实施例8
双极性集流体为复合双极性集流体，为PE基体插入导电碳纤维所制得的薄膜，其余与实施例7相同。
实施例9
双极性集流体为不锈钢金属箔，其余与实施例7相同。
实施例10
制备步骤(1)至(4)与实施例1相同。
(5)电极组件B的制备：将隔膜、双面涂覆负极极片、隔膜、双面涂覆正极极片、隔膜依次层叠设置组成叠片，然后将整个叠片结构的四个角固定好以备用。其中，电极组件B包含一个正极极耳和一个负极极耳，隔膜选用厚度15选用的聚乙烯(PE)膜。
(6)电极组件C的制备：将双面涂覆负极极片、隔膜、双面涂覆正极极片、隔膜依 次层叠设置组成叠片，然后将整个叠片结构的四个角固定好以备用。其中，电极组件C包含一个正极极耳和一个负极极耳，隔膜选用厚度15选用的聚乙烯(PE)膜。。
(7)双极性集流体I和双极性集流体II的制备：采用复合双极性集流体为双极性集流体，为PE基体插入导电碳纤维所制薄膜，厚度为30μm。将步骤(1)中负极活性材料的浆料均匀涂覆在复合双极性集流体的一个表面上，110℃条件下烘干，得到负极活性材料层厚度为150μm。再将步骤(2)中正极活性材料的浆料均匀涂覆在复合双极性集流体的另一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm。其中，双极性集流体密封区域包含密封材料聚丙烯(PP)，聚丙烯密封材料的厚度为20μm，宽度为3mm。其中，密封区域不涂覆电极活性材料。
(8)电极组件A的组装：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，且隔膜一侧朝上，然后将双极性集流体I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。
(9)电极组件B的组装：将组装半成品置于组装夹具内，双极性集流体I负极活性材料的一面朝上，将电极组件B靠近正极极片的隔膜一侧朝下，放置于双极性集流体I上，使得活性材料涂覆区域对应，施加外力压紧得到组装半成品2。
(10)电极组件C的组装：将组装半成品置于组装夹具内，使电极组件B靠近负极极片的隔膜一侧朝上，将双极性集流体II正极活性材料的一面朝下，放置于电极组件B上，然后将电极组件C隔膜一侧朝下，放置于双极性集流体II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放在电极组件C上，采用热压的方式热封四周，得到组装电极组件。其中，热压温度为185℃，热压压力为0.5MPa，密封区域的宽度为2mm，密封区域的厚度为0.03mm。。
(11)注液封装：分别给组装电极组件的三个腔体单独注入电解液，并将电极组件A、B、C的所有极耳引出铝塑膜外，以备后续加工。
(12)电极组件串联连接：将电极组件A的正极极耳和电极组件B的负极极耳通过激光焊的方式焊接连接在一起，实现电极组件A和B之间的串联，将电极组件B的正极极耳和电极组件C的负极极耳通过激光焊的方式焊接连接在一起，实现电极组件B和C之间的串联，电池组装完成。
实施例11
制备步骤(1)至(4)与实施例1相同。
(5)电极组件B的制备：将隔膜、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，然后将整个叠片结构的四个角固定好以备用。其中，电极组件B包含一个正极极耳和一个负极极耳，隔膜选用厚度15μm的聚乙烯(PE)膜。
(6)双极性集流体的制备：采用复合双极性集流体作为双极性集流体的，为PE基体插入导电碳纤维所制薄膜，厚度为30μm。将步骤(2)中正极活性材料的浆料均匀涂覆在复合双极性集流体的一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm。同时从双极性集流体上引出一个极耳以备用。其中，双极性集流体外轮廓密封区域包含密封材料聚丙烯(PP)，聚丙烯的厚度为20μm，涂覆宽度为3mm，且在外轮廓密封区域不涂覆电极活性材料。
(7)电极组件A的组装：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，且隔膜一侧朝上，然后将双极性集流体设置有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。
(8)电极组件B的组装：将组装半成品置于组装夹具内，双极性集流体不设电极活性材料的一面朝上，将电极组件B隔膜一侧朝下，放置于双极性集流体上，使得与半成品各边沿对齐，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。其中，热压温度为185℃，热压压力为0.5MPa，密封区域的宽度为2mm，密封区域的厚度为0.03mm。
(9)注液封装：分别给组装电极组件的两个腔体单独注入电解液，并将电极组件A和B的所有极耳以及双极性集流体的极耳引出铝塑膜外，以备后续加工。
(10)电极组件串联连接：将电极组件A的正极极耳和双极性集流体的极耳通过激光焊的方式焊接连接在一起，再将电极组件B的负极极耳通过激光焊的方式与其焊接连接，实现电极组件A和B之间的串联，电池组装完成。
实施例12
制备步骤(1)至(3)与实施例1相同。
(4)电极组件A的制备：将隔膜、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，然后将整个叠片结构的四个角固定好以备用。其中，电极组件A包含一个正极极耳，隔膜选用厚度15μm的聚乙烯(PE)膜。
(5)电极组件B的制备：将单面涂覆负极极片、隔膜、双面涂覆正极极片依次层叠设置组成叠片，且负极极片未涂覆面朝外放置，然后将整个叠片结构的四个角固定好以备 用。其中，电极组件B包含一个负极极耳，隔膜选用厚度15μm的聚乙烯(PE)膜。
(6)双极性集流体的制备：采用复合双极性集流体作为双极性集流体的，为PE基体插入导电碳纤维所制薄膜，厚度为30μm。将步骤(2)中正极活性材料的浆料均匀涂覆在复合双极性集流体的一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm。其中，双极性集流体外轮廓密封区域包含密封材料聚丙烯(PP)，密封材料聚丙烯的厚度为20μm，宽度为3mm，且在外轮廓密封区域不涂覆电极活性材料。
(7)电极组件A的组装：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，且隔膜一侧朝上，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。
(8)电极组件B的组装：将组装半成品置于组装夹具内，双极性集流体不含电极活性材料的一面朝上，将电极组件B负极极片的未涂覆面朝下，放置于双极性集流体上，使得与半成品各边沿对齐，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。其中，热压温度为185℃，热压压力为0.5MPa，密封区域的宽度为2mm，密封区域的厚度为0.03mm。
(9)注液封装：分别给组装电极组件的两个腔体单独注入电解液，并将电极组件A正极极耳和电极组件B的负极极耳引出铝塑膜外，以备后续加工。
(10)电极组件串联连接：电极组件B的负极极耳与双极性集流体未涂覆面接触并形成电连接，实现电极组件A和B之间的串联，电极组件A正极极耳和电极组件B的负极极耳为输出极耳，电池组装完成。
实施例13
制备步骤(1)至(5)与实施例1相同。
(6)双极性集流体的制备：采用复合双极性集流体作为双极性集流体，即PE基体插入导电碳纤维所制薄膜，厚度为30μm。将步骤(2)中正极活性材料的浆料均匀涂覆在复合双极性集流体的一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm。同时从双极性集流体上引出一个极耳以备用。其中，双极性集流体外轮廓密封区域包含密封材料聚丙烯(PP)，密封材料聚丙烯的厚度为20μm，宽度为3mm，且在外轮廓密封区域不涂覆电极活性材料。
(7)电极组件A的组装：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，且隔膜一侧朝上，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。
(8)电极组件B的组装：将组装半成品置于组装夹具内，双极性集流体不含电极活性材料的一面朝上，将电极组件B负极极片的未涂覆面朝下，放置于双极性集流体上，使得与半成品各边沿对齐，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。其中，热压温度为185℃，热压压力为0.5Mpa，密封区域的宽度为2mm，密封区域的厚度为0.03mm。
(9)注液封装：分别给组装电极组件的两个腔体单独注入电解液，并将电极组件A和B的所有极耳引出铝塑膜外，以备后续加工。
(10)电极组件串联连接：将电极组件A的负极极耳和电极组件B的正极极耳通过激光焊的方式焊接连接在一起，实现电极组件A和B之间的串联，双极性集流体的极耳用于监控电化学装置的电压，电池组装完成。
实施例14
双极性集流体厚度为10μm，其余与实施例1相同。
实施例15
双极性集流体厚度为40μm，其余与实施例1相同。
实施例16
双极性集流体厚度为25μm，其余与实施例1相同。
实施例17
(1)负极极片的制备：将负极极片裁切41mm×550mm的规格待用，其余与实施例1相同。
(2)正极极片的制备：将正极极片裁切成35mm×547mm的规格待用，其余与实施例1相同。
(3)电解液的制备：在干燥氩气气氛中，首先将有机溶剂碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)和碳酸二乙酯(DEC)以质量比EC:EMC:DEC＝30:50:20混合，然后向有机溶剂中加入锂盐六氟磷酸锂(LiPF 6)溶解并混合均匀，得到锂盐的浓度为1.15mol/L的电解液。
(4)电极组件A和电极组件B的制备：将隔膜、双面涂覆负极极片、隔膜、双面涂覆正极极片叠好，然后自一端开始卷绕，最终卷成卷芯负极极片置于最外侧。其中，每个电极组件包含一个正极极耳和一个负极极耳，隔膜选用厚度15μm的聚乙烯(PE)膜。
(5)双极性集流体的制备：采用厚度为30μm的铜铝复合集流体作为双极性集流体。将步骤(1)中负极活性材料的浆料均匀涂覆在铜铝复合集流体的一个表面上，110℃条件下烘干，得到负极活性材料层厚度为150μm。再将步骤(2)中正极活性材料的浆料均匀涂覆在铜铝复合集流体的另一个表面上，90℃条件下烘干，得到正极活性材料层厚度为100μm。其中，双极性集流体密封区域包含密封材料聚丙烯(PP)，密封材料聚丙烯的厚度为20μm，宽度为3mm。其中，密封区域不涂覆电极活性材料。
(6)电极组件A的组装：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。
(7)电极组件B的组装：将组装半成品置于组装夹具内，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，且电极组件B靠近正极极片的隔膜与双极性集流体相邻，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。其中，热压温度为185℃，热压压力为0.5MPa，封印区域的宽度为2mm，封印区域的厚度为0.03mm。
(8)注液封装：分别给组装电极组件的两个腔体单独注入电解液，并将电极组件A和B的所有极耳引出铝塑膜外，以备后续加工。
(9)电极组件串联连接：将电极组件A的正极极耳和电极组件B的负极极耳通过激光焊的方式焊接连接在一起，实现电极组件A和B之间的串联，电池组装完成。
对比例1
将双极性集流体替换为隔板，隔板采用复合PP结构，包括两层表层和一层中间层，表层为熔点140℃，中间为离子绝缘层，熔点为165℃，隔板的厚度为50μm。其余与实施例1相同。
对比例2
制备步骤(1)至(3)与实施例1相同。
(4)电极组件A和电极组件B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，然后将整个叠片结构的四个角固定好以备用，每个电极组件包含一个正极极耳和一个负极极耳。其中，隔膜选用厚度15μm的聚乙烯(PE)膜。
(5)注液封装：将电极组件A和B分别用铝箔包装，再将包装四周密封，分别给电 极组件A和B所在的密封腔体单独注入电解液，并对其进行化成(0.02C恒流充电到3.3V，再以0.1C恒流充电到3.6V)，再将电极组件A和B的所有极耳引出铝塑膜外。
(6)串联连接：将电极组件A与电极组件B于厚度方向堆叠，并将电极组件A的正极极耳和电极组件B的负极极耳通过激光焊的方式焊接连接在一起，实现串联导通。并将辆电极组件主体通过外壳包装在一起，电池组装完成。
各实施例和对比例的数据和测试结果见表1。
表1
Figure PCTCN2020099510-appb-000001
Figure PCTCN2020099510-appb-000002
注：电极组件A收尾结构和电极组件B收尾结构，分别指电极组件A和电极组件B与双极性集流体相邻的结构。
从以上实施例可以看出，使用双极性集流体相比绝缘隔板可提升能量密度约2％。因此，使用双极性集流体作为串联电极组件之间的隔板，不仅实现了提高输出电压、降低充电温升，还提高了电池的电流密度，具有非常好的工业实用性。使用金属双极性集流体时，电池充电温升较小，应该是金属双极性集流体可以将热量传导至外包装的能力更强所致。
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 (17)

  1. 一种电化学装置，其包含双极性集流体，所述双极性集流体与外包装密封连接，在所述双极性集流体两侧形成各自独立的腔体，每个腔体中封装有电极组件和电解液，所述双极性集流体的至少一个表面上设有电极活性材料，相邻腔体中的所述电极组件串联连接。
  2. 根据权利要求1所述的电化学装置，其中，所述双极性集流体的第一表面上设有电极活性材料，所述电极活性材料的极性与相邻的电极组件的最外层电极极片的极性相反，所述最外层电极极片与所述双极性集流体之间设有隔膜；所述双极性集流体的第二表面与相邻的电极组件电绝缘。
  3. 根据权利要求2所述的电化学装置，其中，所述双极性集流体上设置极耳，所述极耳与所述第一表面相邻的电极组件中相同极性的极耳并联连接。
  4. 根据权利要求1所述的电化学装置，其中，所述双极性集流体的第一表面上设有电极活性材料，所述电极活性材料的极性与相邻的电极组件的最外层电极极片的极性相反，所述最外层电极极片与所述双极性集流体之间设有隔膜；所述双极性集流体的第二表面与相邻的电极组件的最外层电极极片的集流体电连接，所述第二表面相邻的电极组件的最外层电极极片的极性与所述第一表面上的电极活性材料的极性相反。
  5. 根据权利要求1所述的电化学装置，其中，所述双极性集流体的两个表面分别设有不同极性的电极活性材料，与每个表面相邻的电极组件的最外层电极极片与该表面上的电极活性材料极性不同，所述电极组件的最外层电极极片与双极性集流体之间设有隔膜。
  6. 根据权利要求5所述的电化学装置，其中，所述电化学装置设置有极性相反的两个极耳，所述电化学装置的电极组件在所述两个极耳之间串联连接。
  7. 根据权利要求5所述的电化学装置，其中，所述电极组件各自设置有极性相反的两个极耳，其中一个极耳与相邻电极组件的极性相反的极耳串联连接。
  8. 根据权利要求5-7的任一项所述的电化学装置，其中，所述双极性集流体上设置有极耳，用于监测其两侧的电极组件的运行状态。
  9. 根据权利要求7所述的电化学装置，其中，所述双极性集流体还设置有极耳，所述极耳与将所述双极性集流体两侧的电极组件相互串联的极耳连接。
  10. 根据权利要求1所述的电化学装置，其中，所述双极性集流体选自金属双极性集流体或复合双极性集流体。
  11. 根据权利要求10所述的电化学装置，其中，所述金属双极性集流体包括不锈钢、Ni、Ti、Ag、Au、Pt双极性集流体中的任一种，所述复合双极性集流体包括铜铝复合集流体及高分子-金属复合集流体中的任一种。
  12. 根据权利要求1所述的电化学装置，其中，所述双极性集流体的厚度为6至100μm。
  13. 根据权利要求1所述的电化学装置，其中，所述电极活性材料包括正极活性材料或负极活性材料，所述正极活性材料包括镍钴锰酸锂、镍钴铝酸锂、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，所述负极活性材料包括人造石墨、天然石墨、中间相碳微球、软碳、硬碳、硅、硅碳、钛酸锂中的至少一种。
  14. 根据权利要求1所述的电化学装置，其中，所述双极性集流体还包括密封区域，所述密封区域位于所述双极性集流体的四周边缘，所述密封区域包含密封材料，所述密封材料包括聚丙烯、酸酐改性聚丙烯、聚乙烯、乙烯-醋酸乙烯共聚物、乙烯-丙烯酸乙酯共聚物、乙烯-丙烯酸共聚物、乙烯-乙烯醇共聚物、聚氯乙烯、聚苯乙烯、聚醚腈、聚氨酯、聚酰胺、聚酯、非晶态α-烯烃共聚物及其衍生物中的至少一种。
  15. 根据权利要求1所述的电化学装置，其中，所述电解液包括凝胶态、固态和液态中的一种。
  16. 根据权利要求1所述的电化学装置，其中，所述腔体为密封腔体。
  17. 一种电子装置，包含如权利要求1至16中任意一项所述电化学装置。
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