WO2021189454A1 - 一种电极组件及包含其的电化学装置和电子装置 - Google Patents

一种电极组件及包含其的电化学装置和电子装置 Download PDF

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Publication number
WO2021189454A1
WO2021189454A1 PCT/CN2020/081798 CN2020081798W WO2021189454A1 WO 2021189454 A1 WO2021189454 A1 WO 2021189454A1 CN 2020081798 W CN2020081798 W CN 2020081798W WO 2021189454 A1 WO2021189454 A1 WO 2021189454A1
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Prior art keywords
isolation layer
tab
porosity
electrode assembly
corner area
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PCT/CN2020/081798
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English (en)
French (fr)
Inventor
黄亮
魏红梅
张益博
胡乔舒
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宁德新能源科技有限公司
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Priority to PCT/CN2020/081798 priority Critical patent/WO2021189454A1/zh
Priority to CN202080095941.1A priority patent/CN115104222B/zh
Publication of WO2021189454A1 publication Critical patent/WO2021189454A1/zh

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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
    • H01M10/05—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
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/534—Electrode connections inside a battery casing characterised by the material of the leads or tabs
    • 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
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of 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
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • 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 application relates to an electrochemical device and an electronic device including the electrochemical device. More specifically, the present application relates to an electrode assembly and an electrochemical device and an electronic device including the same.
  • the diaphragm plays a role in ensuring the conduction of lithium ions and isolating electronic conduction, but there are some problems.
  • the diaphragm material will shrink severely (>5%) at high temperatures (>110°C), causing local positive and negative plates to directly contact and cause short circuits, resulting in safety hazards;
  • the impact of the electrolyte may cause edges when falling.
  • the diaphragm is turned inward (that is, the width of the diaphragm beyond the negative electrode in a normal lithium-ion battery is 0.75mm to 1.5mm.
  • the diaphragm When the diaphragm is impacted by a drop, the diaphragm cannot withstand the impact, causing the diaphragm to curl), causing local direct contact between the positive and negative plates to cause a short circuit.
  • the part of the separator in contact with the positive electrode may be oxidized and decomposed to produce water and carbon dioxide, which deteriorates the interface of the lithium-ion battery, which is not conducive to the long-term stable cycle of the lithium-ion battery; Due to the limitation of the manufacturing process, the traditional diaphragm has a small pore size and cannot achieve high liquid retention.
  • the current is unevenly distributed in the diaphragm area.
  • the area with high current density and stress concentration is due to insufficient electrolyte supply, poor kinetics, lithium ion migration is hindered, and lithium is easily precipitated.
  • Increasing the electrolyte retention in the lithium-prone area can improve lithium precipitation.
  • the traditional diaphragm has a uniform texture and does not have the ability to adjust the electrolyte retention of the diaphragm according to the characteristics of different regions of the lithium-ion battery.
  • the present application provides an electrode assembly to improve the electrolyte holding capacity of the electrochemical device separator.
  • An electrode assembly comprising an electrode pole piece and an isolation layer, the electrode pole piece has tabs, the isolation layer includes a nanofiber porous matrix; the isolation layer has a porosity ⁇ 2 in the tab region greater than that in the non-polar region.
  • the porosity of the non-corner area of the ear is ⁇ 1.
  • the aperture d2 of the isolation layer in the tab region is larger than the aperture d1 in the non- tab region and the corner region.
  • the pore size d3 of the isolation layer in the corner area is greater than its pore size d1 in the non-tab and non-corner area; and/or, the porosity ⁇ 3 of the isolation layer in the corner area is greater than Its porosity in the non-tab and non-corner area is ⁇ 1.
  • the difference d2-d1 between the aperture d2 of the isolation layer in the tab region and the aperture d1 in the non- tab and non-corner region is 50nm to 3000nm; and/or, the isolation
  • the difference ⁇ 2- ⁇ 1 between the porosity ⁇ 2 of the layer in the tab area and the porosity ⁇ 1 in the non-tab and non-corner area is 10% to 50%.
  • the difference d3-d1 between the aperture d3 of the isolation layer in the corner area and the aperture d1 of the non-tab and non-corner area is 50 nm to 3000 nm; and/or, the isolation layer
  • the difference ⁇ 3- ⁇ 1 between the porosity ⁇ 3 in the corner area and the porosity ⁇ 1 in the non-tab and non-corner area is 10% to 50%.
  • the porosity of the isolation layer changes continuously or discontinuously between different regions; the pore size of the isolation layer continuously changes between different regions or It does not change continuously.
  • nanofiber porous matrix comprises high melting point polymer nanofibers and/or low melting point polymer nanofibers.
  • the isolation layer further includes a particle filler
  • the particle filler includes at least one of high melting point polymer particles, low melting point polymer particles, or inorganic particles.
  • the nanofiber matrix and/or particle filler further contains a crosslinking agent and an initiator.
  • the crosslinking agent includes polyisocyanate, hexamethoxymethyl melamine, N-methylol acrylamide, carbodiimide, trimethylolpropane, aziridine, Dicumyl peroxide, butyl acrylate, N,N'-methylenebisacrylamide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, bisphenol A ring At least one of oxy resin, acrylate derivative, nitrile group-containing polymer, styrene, vinyl fluoride, acrylonitrile, acrylic amine, vinyl acetate, alkyl vinyl ether, alkylene oxide or oxetane derivative One;
  • the initiator includes benzoyl oxide, tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, azobisisobutyronitrile, azobisisoheptonitrile, dimethyl azo
  • the electrode assembly has at least one of the following characteristics:
  • the high melting point polymer includes polyvinylidene fluoride, polyimide, polyamide, polyacrylonitrile, polyethylene glycol, polyethylene oxide, polyethylene oxide, polyphenylene ether, polypropylene carbonate Ester, polymethyl methacrylate, polyethylene terephthalate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride-co-chlorotrifluoroethylene) or derivatives of the above At least one of them, preferably poly(vinylidene fluoride-hexafluoropropylene), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyphenylene ether, polypropylene carbonate, polyethylene oxide At least one of alkanes or derivatives of the above substances.
  • the low melting point polymer includes polystyrene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene, polylactic acid, polyvinyl chloride, polyethylene butadiene At least one of aldehyde or polyacrylate.
  • the inorganic particles include HfO 2 , SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, BaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , SiO 2 , Bo Stone, magnesium hydroxide, aluminum hydroxide, lithium phosphate, lithium titanium phosphate, lithium aluminum titanium phosphate, lithium lanthanum titanate, lithium germanium thiophosphate, lithium nitride, SiS 2 glass, P 2 S 5 At least one of glass, Li 2 O, LiF, LiOH, Li 2 CO 3 , LiAlO 2 , Li 2 O-Al 2 O 3 -SiO 2 -P 2 O 5 -TiO 2 -GeO 2 ceramics or garnet ceramics .
  • the particle size of the particle filler is 0.001 ⁇ m to 10 ⁇ m.
  • the volume of the particulate filler accounts for 0% to 95% of the total volume of the solid material of the isolation layer.
  • the isolation layer further has at least one of the following characteristics:
  • the porosity of the isolation layer is 30% to 95%
  • the pore size of the isolation layer is 20 nm to 30 ⁇ m;
  • the thickness of the isolation layer is 1 ⁇ m to 20 ⁇ m
  • the diameter of the nanofibers is 0.1 nm to 5 ⁇ m.
  • the present application also provides an electrochemical device, which includes the above-mentioned electrode assembly.
  • the present application also provides an electronic device, which includes the above-mentioned electrochemical device.
  • the uneven distribution of the pore size or porosity of the isolation layer is adjusted to meet the different liquid retention requirements of different regions of the pole piece.
  • different areas of the pole piece have different dynamic properties, which can slow down the analysis of lithium problems, improve the safety of electrochemical devices, and provide better performance electrochemical devices and electronics Device.
  • FIG. 1 is a schematic diagram of the structure of an electrode assembly according to an embodiment of the application
  • FIG. 2 is a schematic diagram of the structure of an electrode assembly according to an embodiment of the application.
  • FIG. 3 is a schematic diagram of the structure of an electrode assembly according to an embodiment of the application.
  • Fig. 4 shows a schematic structural diagram of an electrode assembly according to an embodiment of the present application
  • FIG. 5 shows a schematic structural diagram of an electrode assembly according to another embodiment of the present application.
  • Fig. 6 shows a schematic structural diagram of an electrode assembly according to an embodiment of the present application
  • FIG. 7 shows a schematic structural diagram of an electrode assembly according to an embodiment of the present application.
  • Fig. 8 shows a schematic structural diagram of an electrode assembly of the present application
  • FIG. 9 is a schematic diagram of an embodiment of preparing an isolation layer according to this application.
  • the electrode assembly of the present application may be any electrode assembly used in an electrochemical device.
  • the electrochemical device may include a lithium ion battery, a super capacitor, etc.
  • the following takes the electrode assembly of a lithium ion battery as an example for description. Those skilled in the art should understand that the following description is only an example and does not limit the protection scope of the present application.
  • One aspect of the present application provides an electrode assembly, which includes an electrode pole piece and an isolation layer, the electrode pole piece has tabs, the isolation layer includes a nanofiber porous matrix, and the porosity of the isolation layer in the tab region ⁇ 2 is greater than its porosity ⁇ 1 in the non-tab and non-corner area.
  • the pore size d3 of the isolation layer in the corner area is larger than its pore size d1 in the non-tab and non-corner area; and/or, the porosity ⁇ 3 of the isolation layer in the corner area It is greater than its porosity ⁇ 1 in the non-tab and non-corner area.
  • the difference d2-d1 between the aperture d2 of the isolation layer in the tab region and the aperture d1 in the non-tab and non-corner region is 50 nm to 3000 nm; and/or, the isolation layer
  • the difference ⁇ 2- ⁇ 1 between the porosity ⁇ 2 in the tab area and the porosity ⁇ 1 in the non-tab and non-corner area is 10% to 50%.
  • the difference d3-d1 between the aperture d3 in the corner area of the isolation layer and the aperture d1 in the non-tab and non-corner area is 50nm to 3000nm; and/or, the isolation layer is in the
  • the difference ⁇ 3- ⁇ 1 between the porosity ⁇ 3 in the corner area and the porosity ⁇ 1 in the non-tab and non-corner area is 10% to 50%.
  • the tab area refers to the area of the entire electrode assembly close to the tab by 5% to 60% of the volume.
  • the corner area refers to the area at the corner of the entire electrode assembly.
  • the non-tab non-corner area refers to the area excluding the tab area and the corner area in the entire electrode assembly.
  • the current is unevenly distributed in the diaphragm area.
  • the closer to the tab the greater the current density, the greater the hard expansion of graphite during the charging process, and the greater the demand for electrolyte.
  • the porosity of the diaphragm is uniformly distributed, so the liquid holding capacity of the diaphragm is also uniform.
  • This application does not use a traditional diaphragm, but instead prepares a fibrous isolation layer on the electrode surface to replace the traditional diaphragm.
  • the tab area has a larger pore size and/or porosity, thereby increasing the amount of liquid retention in the area and increasing the supply of electrolyte to meet the requirements of the tab area. District’s demand for electrolyte. Therefore, different areas of the electrochemical device can have different kinetic properties, the lithium problem can be resolved slowly, and the safety of the electrochemical device can be improved.
  • the stress is concentrated in the corner area of the wound electrochemical device, and the electrolyte retention is lower than that in the non-corner area.
  • the electrolyte supply is insufficient, the kinetics is poor, the lithium ion migration is hindered, and the lithium is easily separated.
  • Analyze lithium This application uses the fiber isolation layer on the electrode surface to replace the traditional diaphragm.
  • the corner area has a larger pore size and/or porosity than the non-tab non-corner area, which can make the corner area have more
  • the high liquid holding capacity realizes that different areas of the electrochemical device have different dynamic properties, so that the electrolyte in the corner area is sufficient, thereby improving the safety performance of the electrochemical device.
  • the porosity of the isolation layer changes continuously or discontinuously between different regions; the pore size of the isolation layer changes continuously or does not change between different regions. Continuously changing.
  • the porosity and pore size of the isolation layer can change in the same way or differently between different regions; the discontinuous change can be a step change.
  • nanofiber porous matrix comprises high melting point polymer nanofibers and/or low melting point polymer nanofibers.
  • the isolation layer further includes a particle filler
  • the particle filler includes at least one of high melting point polymer particles, low melting point polymer particles, or inorganic particles.
  • the electrode assembly has at least one of the following characteristics:
  • the polymer forming the high melting point polymer nanofibers or high melting point polymer particles includes polyvinylidene fluoride, polyimide, polyamide, polyacrylonitrile, polyethylene glycol, polyethylene oxide, poly Ethylene oxide, polyphenylene ether, polypropylene carbonate, polymethyl methacrylate, polyethylene terephthalate, poly(vinylidene fluoride-hexafluoropropylene), poly(vinylidene fluoride- Co-chlorotrifluoroethylene) or at least one of the above derivatives, preferably poly(vinylidene fluoride-hexafluoropropylene), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyphenylene At least one of ether, polypropylene carbonate, polyethylene oxide or derivatives of the above substances;
  • the polymers forming the low-melting polymer nanofibers or low-melting polymer particles include polystyrene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-benzene At least one of ethylene, polylactic acid, polyvinyl chloride, polyvinyl butyral or polyacrylate;
  • the inorganic particles include HfO 2 , SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, BaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , SiO 2 , Bo Stone, magnesium hydroxide, aluminum hydroxide, lithium phosphate, lithium titanium phosphate, lithium aluminum titanium phosphate, lithium lanthanum titanate, lithium germanium thiophosphate, lithium nitride, SiS 2 glass, P 2 S 5 At least one of glass, Li 2 O, LiF, LiOH, Li 2 CO 3 , LiAlO 2 , Li 2 O-Al 2 O 3 -SiO 2 -P 2 O 5 -TiO 2 -GeO 2 ceramics or garnet ceramics ;
  • the particle size of the particle filler is 0.001 ⁇ m to 10 ⁇ m;
  • the volume of the particulate filler accounts for 0% to 95% of the total volume of the solid material of the isolation layer.
  • the melting point of the polymer forming the high melting point polymer nanofibers or high melting point polymer particles is generally greater than 170°C.
  • the melting point of the polymer forming the low-melting polymer particles or low-melting polymer nanofibers is generally 70°C to 120°C.
  • the low melting point particles melt at a lower temperature and seal the pores of the isolation layer, thereby stopping the charging and discharging process, which can improve the safety of the battery.
  • the volume of the particle filler accounts for 0% to 95%, preferably 30% to 70% of the total volume of the solid matter of the isolation layer. Wherein, the total volume of the solid matter of the isolation layer does not include the volume of the pores in the isolation layer.
  • inorganic particles account for 0% to 95%, preferably 10% to 70%, of the volume of the solid matter of the isolation layer.
  • the total volume of the solid matter of the isolation layer does not include the volume of the pores in the isolation layer.
  • the particle size of the inorganic particles is 0.001 ⁇ m to 10 ⁇ m.
  • the isolation layer further has at least one of the following characteristics:
  • the porosity of the isolation layer is 20% to 95%, preferably 30% to 80%;
  • the pore size of the isolation layer is 20 nm to 30 ⁇ m, preferably 50 nm to 10 ⁇ m;
  • the thickness of the isolation layer is 1 ⁇ m to 20 ⁇ m, preferably 5 ⁇ m to 10 ⁇ m;
  • the diameter of the nanofibers is 0.1 nm to 5 ⁇ m, preferably 0.5 nm to 1 ⁇ m.
  • the porosity of the isolation layer By setting the porosity of the isolation layer within the above range, the ion conductivity can be ensured. If the porosity is too small, it will cause blockage of the ion transmission path and hinder the normal circulation of the electrochemical device. If the porosity is too large, the structure will be unstable, and the mechanical strength will be too poor, and it will not be able to resist the puncture of the particles on the surface of the pole piece. It is easy to cause a local short circuit of the positive and negative electrodes, resulting in electrical performance degradation and serious self-discharge problems.
  • the isolation layer By making the pore size range of the isolation layer within the above range, it is possible to ensure that the isolation layer has appropriate mechanical strength. If the pore size is too small, the ion transmission path will be insufficient, which will hinder the normal circulation of the electrochemical device. If the pore size is too large, the mechanical strength at the position of the hole will be too poor, and it will not be able to resist the puncture of the particles on the surface of the pole piece. It is easy to cause partial short circuit of the positive and negative electrodes, resulting in electrical performance degradation and serious self-discharge problems.
  • the thickness of the isolation layer is ensured to be equal to or less than that of the existing separator, which is beneficial to increase the energy density of the electrochemical device.
  • the isolation layer can have proper porosity, improve the liquid retention capacity of the isolation layer, and at the same time ensure that the isolation layer has proper strength, together with the particle filler distributed in the isolation layer Improve the strength of the isolation layer to prevent the isolation layer from being pierced by the positive and negative active material particles.
  • a crosslinking agent and an initiator may be added to the nanofiber matrix and/or particle filler.
  • the crosslinking agent and initiator are not particularly limited.
  • the crosslinking agent may include polyisocyanate, hexamethylene Oxymethyl melamine, N-methylolacrylamide, carbodiimide, trimethylolpropane, aziridine, dicumyl peroxide, butyl acrylate, N,N'-methylenebispropylene Amide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, bisphenol A epoxy resin, acrylate derivatives, nitrile group-containing polymers, styrene, vinyl fluoride, propylene At least one of nitrile, acrylic amine, vinyl acetate, alkyl vinyl ether, alkylene oxide or oxetane derivative; the initiator may include benzoyl oxide, tert-butyl benzoyl peroxide Ester,
  • the isolation layer may be formed on the surface of the electrode active material layer.
  • the electrode active material layer may be a positive electrode active material layer and/or a negative electrode active material layer.
  • the isolation layer may be formed on the surface of the current collector.
  • the current collector may be a positive electrode current collector and/or a negative electrode current collector.
  • the isolation layer is directly formed on the surface of the current collector.
  • the isolation layer may be formed on the surface of the tab.
  • the tab can be a positive tab and/or a negative tab.
  • the isolation layer may be formed on one surface of the positive pole piece and one surface of the negative pole piece, and then follow the manner of negative pole piece + isolation layer, positive pole piece + isolation layer. The lamination is performed to form an electrode assembly.
  • the isolation layer may be formed on both surfaces of the positive pole piece, and then laminated in the manner of the negative pole piece, the isolation layer + the positive pole piece + the isolation layer, to form an electrode A component in which there is no separator on the surface of the negative pole piece.
  • the isolation layer may be formed on both surfaces of the negative pole piece, and then laminated in the manner of isolation layer + negative pole piece + isolation layer, and positive pole piece to form an electrode assembly , Where there is no isolation layer on the positive pole piece.
  • the electrode assembly formed in the above embodiment may continue to be stacked in the above order, or it may be directly wound to form a multilayer lithium ion battery.
  • the positive electrode tab usually includes a positive electrode current collector and a positive electrode active material.
  • the positive electrode current collector is not particularly limited, and may be any positive electrode current collector known in the art, such as aluminum foil, aluminum alloy foil, or composite current collector.
  • the positive electrode active material is not particularly limited, and can be any positive electrode active material in the prior art.
  • the active material includes NCM811, NCM622, NCM523, NCM111, NCA, lithium iron phosphate, lithium cobalt oxide, lithium manganate, and ferromanganese phosphate. At least one of lithium or lithium titanate.
  • the positive pole piece may further include a conductive layer located between the positive electrode current collector and the positive electrode active material.
  • 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 usually includes a negative current collector and a negative 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, copper alloy foil or composite current collector.
  • the negative active material is not particularly limited, and any negative active material known in the art can be used. For example, it may include at least one of graphite, silicon, or silicon carbon.
  • the negative pole piece may further include a conductive layer located between the negative current collector and the negative active material.
  • 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 conductive agent used in the above-mentioned positive pole piece and negative pole piece is not particularly limited, and any conductive agent known in the art can be used as long as the purpose of the application can be achieved.
  • the conductive agent may include at least one of conductive carbon black (Super P), carbon nanotubes (CNTs), carbon fiber, graphene, and the like.
  • the conductive agent can be conductive carbon black (Super P).
  • the aforementioned adhesive is not particularly limited, and any adhesive known in the art can be used as long as it can achieve the purpose of the present application.
  • the adhesive may include at least one of styrene-butadiene rubber (SBR), polyvinyl alcohol (PVA), polytetrafluoroethylene (PTFE), sodium carboxymethyl cellulose (Na-CMC), and the like.
  • SBR styrene-butadiene rubber
  • PVA polyvinyl alcohol
  • PTFE polytetrafluoroethylene
  • Na-CMC sodium carboxymethyl cellulose
  • the adhesive can be styrene butadiene rubber (SBR).
  • the present application also provides an electrochemical device, which includes the electrode assembly of the present application.
  • the electrochemical device is a lithium ion battery.
  • the present application has no particular limitation on the electrolyte of the lithium ion battery, and any electrolyte known in the art can be used, and the electrolyte can be any of a gel state, a solid state, and a liquid state.
  • the liquid electrolyte includes a lithium salt and a 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 application can be achieved.
  • the lithium salt 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 and the like.
  • LiPF 6 can be used 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, or other organic solvents.
  • the carbonate compound may include diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethylene propyl carbonate (EPC), methyl ethyl carbonate Ester (MEC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinyl ethylene carbonate (VEC), fluoroethylene carbonate (FEC), carbonic acid 1 ,2-Difluoroethylene, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1 -Fluoro-2-methylethylene, 1-fluoro-1-methylethylene carbonate, 1,2-difluoro-1-methylethylene carbonate, 1,1,2-trifluorocarbonate- At least one of 2-methylethylene, trifluoromethylethylene carbonate, and the like.
  • DEC diethyl carbonate
  • DMC dimethyl carbonate
  • the present application does not make additional restrictions on the method for preparing the above-mentioned electrode assembly, and any method known in the art may be used for preparation.
  • the nanofiber porous matrix can be prepared by processes such as electrospinning, air spinning, centrifugal spinning, electroblowing, melt blowing, flash evaporation, coating, etc.
  • the particle filler can be prepared by It is prepared by electrodeposition method, printing method, coating method, rotating method, dipping method and other processes.
  • the order of depositing the nanofiber porous matrix and the particle filler is not particularly limited, as long as the isolation layer of the present application can be formed.
  • the nanofiber porous matrix and the particulate filler can be deposited simultaneously or alternately.
  • the nanofiber porous matrix can be implemented with any spinning equipment known in the art, and is not particularly limited, as long as the purpose of the application can be achieved, and any spinning equipment known in the art can be used, such as electrospinning equipment. It is the Elite series of Yongkang Leye; the air spinning equipment can be the air jet spinning machine of Nanjing Genus New Material; the centrifugal spinning equipment can be the centrifugal spinning machine of Sichuan Zhiyan Technology.
  • the electrodeposition method can be implemented with any equipment known in the art, and is not particularly limited, as long as the purpose of the application can be achieved. For example, the electrostatic spraying equipment of Samez, France can be used.
  • FIG. 1 shows a schematic diagram of the structure of an electrode assembly according to an embodiment of the present application.
  • an isolation layer is provided on one surface of the electrode pole piece.
  • the separator layer 3 is coated on the positive electrode active material layer 2 and sandwiched between the positive electrode active material layer 2 and the negative electrode active material layer 4.
  • the positive electrode active material layer is coated on the positive electrode current collector 1.
  • the material layer is coated on the negative electrode current collector 5;
  • FIG. 2 shows a schematic diagram of the structure of an electrode assembly according to an embodiment of the present application, in which isolation layers are provided on both surfaces of the positive pole piece.
  • Two separator layers 3 are respectively coated on the two positive electrode active material layers 2, and one separator layer is sandwiched between the positive electrode active material layer 2 and the negative electrode active material layer 4, and the positive electrode active material layer is coated on the positive electrode collector.
  • the negative active material layer is coated on both surfaces of the negative current collector 5;
  • FIG. 3 shows a schematic diagram of the structure of an electrode assembly according to an embodiment of the present application, in which isolation layers are provided on both surfaces of the negative pole piece.
  • Two separation layers 3 are respectively coated on the two negative electrode active material layers 4, one of which is sandwiched between the positive electrode active material layer 2 and the negative electrode active material layer 4, and the positive electrode active material layer is coated on the positive electrode collector.
  • the negative active material layer is coated on both surfaces of the negative current collector 5;
  • FIG. 4 shows a schematic structural diagram of an electrode assembly according to an embodiment of the present application, in which the tab 6 and the porous nanofiber matrix 7 are shown, and the porosity of the porous nanofiber matrix in the tab region 8 is greater than that of the non- tabs.
  • Figure 5 shows a schematic structural diagram of an electrode assembly according to another embodiment of the present application, in which the tab 6 and the porous nanofiber matrix 7 are shown.
  • the pore size of the porous nanofiber matrix in the tab region 8 is larger than that of the non- tab
  • Figure 6 shows a schematic structural diagram of an electrode assembly according to another embodiment of the present application, in which two tabs 6 and a porous nanofiber matrix 7 are shown.
  • the pore size of the porous nanofiber matrix in the tab region 8 is larger than that of non The pore size of the porous nanofiber matrix in the tab area;
  • FIG. 7 shows a schematic structural diagram of an electrode assembly according to another embodiment of the present application, in which the tab 6, the isolation layer 3, and the positive electrode active material layer 2 are shown.
  • the porosity of the nanofiber porous matrix in the tab region is greater than The porosity of the porous nanofiber matrix in the non-tip region;
  • FIG. 8 shows a schematic structural diagram of an electrode assembly according to another embodiment of the present application, in which the tab 6, the tab region 8, and the corner region 9 are shown.
  • FIG. 9 is a schematic diagram of an embodiment of preparing an isolation layer according to this application, in which the electrospinning device 10 and the electrodeposition device 11 respectively deposit fibers and polymer particles on the surface of the electrode; the electrospinning device 10 and the electrodeposition The devices 11 are all connected to the voltage stabilizer 12.
  • the present application also provides an electronic device, which includes the electrochemical device of the present application.
  • the electronic devices described in this application include electronic devices generally in the field, such as notebook computers, mobile phones, electric motorcycles, electric cars, electric toys, and the like.
  • Average particle size of polymer particles The average particle size of polymer particles is represented by volume-based D50, that is, the volume content of polymer particles with a particle size below D50 accounts for 50% of all particles.
  • Average particle size of inorganic particles is represented by volume-based D50, that is, the volume content of inorganic particles with a particle size below D50 accounts for 50% of all particles.
  • the lithium-ion battery is charged at a rate of 1C first, then fully charged to the cut-off voltage, and discharged to the cut-off voltage at a rate of 0.7C. After this test process is cycled for 15 times, the lithium-ion battery is fully charged with a current of 1C to end the charge Process.
  • the negative electrode active material graphite (Graphite), conductive carbon black (Super P), and styrene butadiene rubber (SBR) are mixed in a weight ratio of 96:1.5:2.5, and deionized water (H 2 O) is added as a solvent to prepare a solid content For the slurry of 0.7, and stir evenly.
  • the slurry was uniformly coated on one surface of a negative electrode current collector copper foil with a thickness of 8 ⁇ m, and dried at 110° C. to obtain a negative electrode sheet with a coating thickness of 130 ⁇ m on a single side coated with a negative electrode active material.
  • Repeat the above steps on the other surface of the negative pole piece to obtain a negative pole piece coated with negative active material on both sides. Then, cut the pole piece into (41mm ⁇ 61mm) specifications for later use.
  • the positive active material lithium cobalt oxide (LiCoO 2 ), conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 97.5:1.0:1.5, and N-methylpyrrolidone (NMP) was added as a solvent , Formulated into a slurry with a solid content of 0.75, and stirred evenly.
  • the slurry was uniformly coated on one surface of a positive electrode current collector aluminum foil with a thickness of 10 ⁇ m and dried at 90° C. to obtain a positive electrode piece with a coating thickness of 110 ⁇ m. Repeat the above steps on the other surface of the aluminum foil of the positive electrode current collector to obtain a positive electrode piece that has been coated on both sides. After coating, cut the pole piece into (38mm ⁇ 58mm) specifications for later use.
  • the lithium salt lithium hexafluorophosphate (LiPF 6 ) is added to the organic solvent to dissolve and mix uniformly to obtain an electrolyte with a lithium salt concentration of 1.15M.
  • the following examples illustrate the preparation of the isolation layer of the nanofiber porous matrix according to the present application. These embodiments are described by taking the positive pole piece as an example, and an integrated isolation layer is deposited on both surfaces of the positive pole piece. It should be understood that the integrated isolation layer may also be deposited on both surfaces of the negative pole piece, or an integrated isolation layer may be deposited on one surface of the positive pole piece and one surface of the negative pole piece. The method can also achieve the purpose of this application. Those skilled in the art should understand that these implementations are also within the protection scope of the present application.
  • nanofibers were prepared by electrospinning, wherein the diameter of the nanofibers was 100 nm, the spinning amount was 5.0 g/m 2 , and the electrode
  • the average pore diameter of the isolation layer in the ear area and the corner area is 600nm, and the porosity is 50%; the average pore diameter of the isolation layer in the non-tip and non-corner area is 500nm, and the spinning volume is 5.1g/m 2 ; the porosity is 50%,
  • the thickness of the isolation layer is 10 ⁇ m.
  • the single-sided coating of the positive pole piece has been completed. After that, repeat the above steps on the other surface of the positive pole piece, and vacuum dry at 40°C to remove dispersants such as DMF, and then raise the temperature to 80°C for heat treatment for 6 hours to complete the cross-linking process, and then double-sided Positive pole piece coated with separator.
  • Example 1 Except that the average pore diameter of the isolation layer in the tab area and the corner area is 1000 nm, and the spinning amount is 4.7 g/m 2 , the rest is the same as in Example 1.
  • Example 1 Except that the average pore diameter of the isolation layer in the tab area and the corner area is 3000 nm, and the spinning amount is 3.5 g/m 2 , the rest is the same as in Example 1.
  • a nanofiber porous matrix with a thickness of 10 ⁇ m was prepared by an electrospinning method. Among them, the diameter of the nanofibers used is 100 ⁇ m;
  • the average pore size of the isolation layer in the tab area and the corner area is 500nm, and the spinning volume is 5.1g/m 2 , the average pore size of the isolation layer in the non-tab area and the corner area is 500nm, and the spinning volume is 5.1g/m 2 ;
  • the average porosity of the isolation layer in the tab area and the corner area is 60%, and the average porosity of the isolation layer in the non-tab area and the corner area is 50%.
  • Example 4 Except that the average porosity of the isolation layer in the tab area and the corner area is 70%, and the spinning amount is 4.9 g/m 2 , the rest is the same as in Example 4.
  • a nanofiber porous matrix with a thickness of 10 ⁇ m was prepared by an electrospinning method. Among them, the diameter of the nanofibers used is 100 ⁇ m;
  • the average pore size of the isolation layer in the tab area and the corner area is 600nm, the spinning volume is 4.7g/m 2 , the average pore size of the isolation layer in the non-tab and corner area is 500nm, and the spinning volume is 5.3g/m 2 ;
  • the average porosity of the isolation layer in the tab area and the corner area is 70%, and the average porosity of the isolation layer in the non-tab area and the corner area is 30%.
  • the average porosity of the isolation layer except for the tab area and the corner area is 70%, the spinning volume is 4.7g/m 2 , the porosity of the non-tab and non-corner area is 40%, and the spinning volume is 5.2g/m Except for 2 , the rest is the same as in Example 7.
  • the average porosity of the isolation layer except for the tab area and the corner area is 70%, the spinning volume is 4.7g/m 2 , the porosity of the non-tab and non-corner area is 40%, and the spinning volume is 5.2g/m Except for 2 , the rest is the same as in Example 7.
  • the average pore diameter of the isolation layer except for the tab area and the corner area is 1000 nm, the average porosity is 70%, the spinning volume is 4.3 g/m 2 , the porosity of the non-tip and corner areas is 50%, and the spinning volume is Except for 5.1 g/m 2 , the rest is the same as in Example 7.
  • the average pore diameter of the isolation layer except the tab area and the corner area is 800nm, the average porosity is 65%, and the spinning volume is 4.5g/m 2.
  • the average porosity of the isolation layer in the non-tab and corner area is 50%.
  • the yarn weight is the same as in Example 7 except that the yarn weight is 5.1 g/m 2.
  • the average pore diameter of the isolation layer except the tab area and the corner area is 600nm, the average porosity is 60%, and the spinning volume is 4.7g/m 2.
  • the average porosity of the isolation layer in the non-tab and corner area is 50%.
  • the yarn weight is the same as in Example 7 except that the yarn weight is 5.1 g/m 2.
  • a layer of nanofiber porous matrix with a thickness of 10 ⁇ m was prepared by an electrospinning method. Among them, the diameter of the nanofibers used is 100 ⁇ m;
  • the average pore size of the isolation layer in the tab area is 900nm, the average porosity is 63%, the spinning volume is 4.5g/m 2 , the average pore size of the isolation layer in the corner area is 700nm, the average porosity is 73%, and the spinning volume It is 4.4 g/m 2 , the average pore diameter of the isolation layer in the non-tab and non-corner area is 500 nm, the average porosity is 50%, and the spinning amount is 5.1 g/m 2 .
  • the average pore diameter in the tab-except area is 850nm, the average porosity is 67%, the spinning volume is 4.5g/m 2 , the average pore diameter of the isolation layer in the corner area is 750nm, the average porosity is 68%, and the spinning volume is 4.5g/ Except for m 2 , the rest is the same as in Example 13.
  • the average pore diameter in the tab-except area is 760nm, the average porosity is 70%, the spinning volume is 4.2g/m 2 , the average pore diameter of the isolation layer in the corner area is 800nm, the average porosity is 66%, and the spinning volume is 4.3g/ Except for m 2 , the rest is the same as in Example 13.
  • a porous nanofiber matrix with a thickness of 20 ⁇ m was prepared by an electrospinning method. While spinning, the polyethylene particles are sprayed simultaneously by the electrospray method, and the polyethylene particles are distributed in the porous fiber matrix in a filling manner.
  • the diameter of the nanofibers used is 100 ⁇ m, the average pore diameter of the isolation layer in the tab area and the corner area is 600 nm, and the spinning volume is 9.9 g/m 2 ; the porosity is 70%; The average pore diameter of the isolation layer is 500nm, the average porosity is 50%, and the spinning volume is 9.7g/m 2 ; the average particle size of polyethylene (PE) particles is 500nm, and the polyethylene (PE) particles account for the total solid matter of the entire isolation layer. 60% of the volume, the total volume of the solid matter of the isolation layer does not include the volume of the pores in the isolation layer.
  • the single-sided coating of the positive pole piece has been completed. After that, repeat the above steps on the other surface of the positive pole piece, and vacuum dry at 40°C to remove dispersants such as DMF, and then raise the temperature to 80°C for heat treatment for 6 hours to complete the cross-linking process, and then double-sided Positive pole piece coated with separator.
  • a nanofiber porous matrix with a thickness of 10 ⁇ m was prepared by an electrospinning method.
  • the diameter of the nanofibers used is 100 ⁇ m
  • the average pore diameter of the isolation layer in the tab area is 850nm
  • the spinning volume is 4.5g/m 2
  • the porosity is 67%
  • the average pore size of the isolation layer in the corner area is 750nm
  • the spinning amount is 4.5g/m 2
  • the porosity is 68%.
  • the average pore diameter of the isolation layer in the non-tab and non-corner area is 500nm, the average porosity is 50%, and the spinning volume is 4.3g/m 2 ;
  • the inorganic boehmite particles While spinning, the inorganic boehmite particles are dispersed in DMF/acetone (7:3) solvent, and stirred until the slurry viscosity is stable, and a suspension B with a mass fraction of 40% is obtained as a raw material, using electricity
  • the spraying method sprays the inorganic particles simultaneously, and the boehmite is distributed in the porous fiber matrix in a filling manner.
  • the average particle size of boehmite particles is 500 nm
  • boehmite occupies 10% of the total volume of the solid matter of the entire isolation layer
  • the total volume of the solid matter of the isolation layer does not include the volume of the pores in the isolation layer.
  • the single-sided coating of the positive pole piece has been completed. After that, repeat the above steps on the other surface of the positive pole piece, and vacuum dry at 40°C to remove dispersants such as DMF, and then raise the temperature to 80°C for heat treatment for 6 hours to complete the cross-linking process, and then double-sided Positive pole piece coated with separator.
  • the spinning amount in the non-tab and non-corner area is 3.8g/m 2
  • the average particle size of boehmite particles is 200nm
  • the spinning amount in the non-tip and non-corner area is 3.8g/m 2
  • the average particle size of boehmite particles is 1000nm
  • a porous nanofiber matrix with a thickness of 10 ⁇ m was prepared by the electrospinning method and the electrospinning method.
  • the diameter of the nanofibers used is 100nm
  • the average pore size of the isolation layer in the tab area is 850nm
  • the porosity is 67%
  • the spinning volume is 4.5g/m 2
  • the average pore size of the isolation layer in the corner area is 750nm
  • the porosity is 68%
  • the spinning volume is 4.5g/m 2 .
  • the average pore diameter of the isolation layer in the non-tab and non-corner region is 500 nm, the spinning amount is 5.1 g/m 2 , the porosity is 50%, and the thickness of the isolation layer is 10 ⁇ m.
  • the single-sided coating of the positive pole piece has been completed. After that, repeat the above steps on the other surface of the positive pole piece, and vacuum dry at 40°C to remove dispersants such as DMF, and then raise the temperature to 80°C for heat treatment for 6 hours to complete the cross-linking process, and then double-sided Positive pole piece coated with separator.
  • the average pore diameter of the isolation layer in the non-tab and non-corner region is 500 nm
  • the spinning amount is 9.8 g/m 2
  • the porosity is 50%
  • the thickness of the isolation layer is 20 ⁇ m, the rest is the same as in Example 22.
  • the positive pole piece prepared in each embodiment and the negative pole piece prepared in Preparation Example 1 were relatively stacked and wound into an electrode assembly. After the end of the winding structure, the tabs, and the cathode head area are glued, they are placed in an aluminum plastic film, sealed on the top side, injected with the electrolyte of Preparation Example 3, and packaged to finally obtain a lithium ion battery.
  • PE Polyethylene
  • the separator placed between the negative pole piece in Preparation Example 1 and the positive pole piece in Preparation Example 2 as a separator, and the negative pole piece, positive pole piece and separator Relatively stacked and wound into an electrode assembly.
  • the tabs, and the cathode head area are glued, they are placed in an aluminum plastic film, sealed on the top side, injected with the electrolyte of Preparation Example 3, and packaged to finally obtain a lithium ion battery.
  • a PVDF non-woven fabric separator with a thickness of 10 ⁇ m was prepared by using solution A as a raw material by a method of mixing electrospinning and air spinning. The rate is 80%.
  • the single-sided coating of the positive pole piece has been completed. After that, repeat the above steps on the other surface of the positive pole piece, and vacuum dry at 40°C to remove dispersants such as DMF, and then raise the temperature to 80°C for heat treatment for 6 hours to complete the cross-linking process, and then double-sided Positive pole piece coated with separator.
  • the negative pole piece in Preparation Example 1 and the positive pole piece with a separator prepared above are relatively stacked and wound into an electrode assembly. After the end of the winding structure, the tabs, and the cathode head area are glued, they are placed in an aluminum plastic film, sealed on the top side, injected with the electrolyte of Preparation Example 3, and packaged to finally obtain a lithium ion battery.
  • Example 22 Except that the spinning amount in the non-tab and non-corner area is 1.1 g/m 2 , and the thickness of the isolation layer is 1 ⁇ m, the rest is the same as in Example 22.
  • the negative pole piece in Preparation Example 1 and the positive pole piece prepared in Comparative Example 3 were relatively stacked and wound into an electrode assembly. After the end of the winding structure, the tabs, and the cathode head area are glued, they are placed in an aluminum plastic film, sealed on the top side, injected with the electrolyte of Preparation Example 3, and packaged to finally obtain a lithium ion battery.
  • the electrode assembly provided by the present application regulates the uneven distribution of the pore size or porosity of the isolation layer, so that the tab area and/or the corner area
  • the porosity and/or pore size is larger, and the liquid holding capacity is larger, so as to meet the different liquid holding capacity requirements of different regions of the pole piece.

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Abstract

一种电极组件，其包括电极极片和隔离层（3），所述电极极片具有极耳（6），所述隔离层（3）包含纳米纤维多孔基体（7），所述隔离层（3）在极耳区（8）的孔隙率α2大于其在非极耳非拐角区的孔隙率α1；所述隔离层（3）在拐角区（9）的孔径d3大于其在非极耳非拐角区的孔径d1。通过调控隔离层（3）孔隙率的不均匀分布，满足极片不同区域不同的保液量需求。通过提升极耳区（8）的保液量，实现极片不同区域具有不同的动力学性能，进而缓解析锂问题，提升锂离子电池安全性。

Description

一种电极组件及包含其的电化学装置和电子装置 技术领域
本申请涉及一种电化学装置和包含所述电化学装置的电子装置，更具体地，本申请涉及一种电极组件及包含其的电化学装置和电子装置。
背景技术
传统锂离子电池具有体积(～700Wh/L)和质量(～300Wh/kg)能量密度高、循环寿命长(～500圈)、标称电压高(>3.7V)、自放电率低(<1.2mV/hr)、体积小、重量轻等许多优点，在消费电子领域具有广泛的应用。随着近年来电动汽车和可移动电子设备的高速发展，人们对电池的能量密度(>700Wh/L)、安全性、循环性能(>500圈)等相关需求越来越高，期待着综合性能全面提升的新型锂离子电池的出现。其中，无隔膜锂离子电池是其中备受瞩目的一种新型电池。
在现有锂离子电池体系中，隔膜起到了保证锂离子传导并隔绝电子传导的作用，但是存在一些问题。首先，隔膜材料在高温下(＞110℃)会发生严重收缩(>5％)，导致局部正负极片直接接触引发短路，产生安全隐患；其次，在跌落时由于电解液的冲击可能引发边缘处隔膜内翻(即正常锂离子电池中隔膜超出负极区域为宽度0.75mm至1.5mm，当受到跌落冲击后，隔膜无法承受冲击，使得隔膜蜷曲)，导致局部正负极片直接接触引发短路，产生安全隐患；此外，在正极处于满充状态下时，隔膜与正极接触的部分可能会被氧化分解生成水和二氧化碳，恶化锂离子电池界面，不利于锂离子电池的长期稳定循环；再者，传统隔膜由于制作工艺限制，孔径较小，无法实现高保液。
锂离子电池中电流在膜片区分布不均匀，距离极耳越近电流密度越大，充电过程中石墨硬膨胀越大，对电解液需求量越大；此外，卷绕锂离子电池中拐角区域应力集中，电解液保有量较非拐角区域低。电池中，电流密度大和应力集中的区域由于电解液量补充不足，动力学差，锂离子迁移受阻，容易析锂，提升易析锂区域的电解液保有量可以改善析锂。传统隔膜质地均匀，不具备根据锂离子电池的不同区域特性调整隔膜电解液保有量的能力。
发明内容
基于现有技术的缺陷，本申请提供一种电极组件，以改善电化学装置隔膜的电解液保有量能力。
一种电极组件，其包括电极极片和隔离层，所述电极极片具有极耳，所述隔离层包含 纳米纤维多孔基体；所述隔离层在极耳区的孔隙率α2大于其在非极耳非拐角区的孔隙率α1。
在本申请的一些实施方式中，其中，所述隔离层在极耳区的孔径d2大于其在非极耳非拐角区的孔径d1。
在本申请的一些实施方式中，其中，所述隔离层在拐角区的孔径d3大于其在非极耳非拐角区的孔径d1；和/或，所述隔离层在拐角区的孔隙率α3大于其在非极耳非拐角区的孔隙率α1。
在本申请的一些实施方式中，其中，所述隔离层在极耳区的孔径d2与其在非极耳非拐角区的孔径d1之差d2-d1为50nm至3000nm；和/或，所述隔离层在极耳区的孔隙率α2与其在非极耳非拐角区的孔隙率α1之差α2-α1为10％至50％。
在本申请的一些实施方式中，其中，所述隔离层在拐角区的孔径d3与其在非极耳非拐角区的孔径d1之差d3-d1为50nm至3000nm；和/或，所述隔离层在拐角区的孔隙率α3与其在非极耳非拐角区的孔隙率α1之差α3-α1为10％至50％。
在本申请的一些实施方式中，其中，所述隔离层的孔隙率在不同区域之间是连续变化的或者是不连续变化的；所述隔离层的孔径在不同区域之间是连续变化的或者是不连续变化的。
在本申请的一些实施方式中，其中所述纳米纤维多孔基体包含高熔点聚合物纳米纤维和/或低熔点聚合物纳米纤维。
在本申请的一些实施方式中，其中，所述隔离层还包含颗粒填充物，所述颗粒填充物包括高熔点聚合物颗粒、低熔点聚合物颗粒或无机颗粒中的至少一种。
在本申请的一些实施方式中，其中所述纳米纤维基体和/或颗粒填充物中还包含交联剂和引发剂。
在本申请的一些实施方式中，其中，所述交联剂包括多异氰酸酯、六甲氧基甲基三聚氰胺、N-羟甲基丙烯酰胺、碳二亚胺、三羟甲基丙烷、氮丙啶、过氧化二异丙苯、丙烯酸丁酯、N,N'-亚甲基双丙烯酰胺、2,5-二甲基-2,5-双(过氧化叔丁基)己烷、双酚A环氧树脂、丙烯酸酯衍生物、含腈基聚合物、苯乙烯、氟乙烯、丙烯腈、丙烯酸胺、醋酸乙烯酯、烷基乙烯基醚、环氧烷烃或氧杂环丁烷衍生物中的至少一种；所述引发剂包括氧化苯甲酰、过氧化苯甲酰叔丁酯、过氧化甲乙酮、偶氮二异丁腈、偶氮二异庚腈、偶氮二异丁酸二甲酯、偶氮二异丁基脒盐酸盐、三氟化硼、五氟化磷、四氯化钛、四氯化锡或二氯化锌中的至少一种。
在本申请的一些实施方式中，电极组件具有以下特征中的至少一者：
(a)所述高熔点聚合物包括聚偏二氟乙烯、聚酰亚胺、聚酰胺、聚丙烯腈、聚乙二醇、聚氧化乙烯、聚氧化乙烷、聚苯醚、聚碳酸亚丙酯、聚甲基丙烯酸甲酯、聚对苯二甲酸乙二醇酯，聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)或上述物质的衍生物中的至少一种，优选聚(偏二氟乙烯-六氟丙烯)、聚偏二氟乙烯、聚丙烯腈、聚甲基丙烯酸甲酯、聚苯醚、聚碳酸亚丙酯、聚氧化乙烷或上述物质的衍生物中的至少一种。
(b)所述低熔点聚合物包括聚苯乙烯、聚乙烯、乙烯-丙烯共聚物、乙烯-醋酸乙烯共聚物、丙烯腈-丁二烯-苯乙烯、聚乳酸、聚氯乙烯、聚乙烯丁醛或聚丙烯酸酯中的至少一种。
(c)所述无机颗粒包括HfO 2、SrTiO 3、SnO 2、CeO 2、MgO、NiO、CaO、BaO、ZnO、ZrO 2、Y 2O 3、Al 2O 3、TiO 2、SiO 2、勃姆石、氢氧化镁、氢氧化铝、磷酸锂、锂钛磷酸盐、锂铝钛磷酸盐、锂镧钛酸盐、锂锗硫代磷酸盐、锂氮化物、SiS 2玻璃、P 2S 5玻璃、Li 2O、LiF、LiOH、Li 2CO 3、LiAlO 2、Li 2O-Al 2O 3-SiO 2-P 2O 5-TiO 2-GeO 2陶瓷或石榴石陶瓷中的至少一种。
(d)所述颗粒填充物的粒径大小为0.001μm至10μm。
(e)所述颗粒填充物的体积占隔离层固体物质总体积的0％至95％。
在本申请的一些实施方式中，其中，所述隔离层还具有以下特征中的至少一者：
(a)所述隔离层的孔隙率为30％至95％；
(b)所述隔离层的孔径为20nm至30μm；
(c)所述隔离层的厚度为1μm至20μm
(d)所述纳米纤维的直径为0.1nm至5μm。
本申请同时提供一种电化学装置，其包含上述的电极组件。
本申请同时提供一种电子装置，其包含上述的电化学装置。
本申请通过调控隔离层孔径或孔隙率的不均匀分布，满足极片不同区域不同的保液量需求。通过提升极耳区和拐角区的保液量，实现极片不同区域具有不同的动力学性能，进而缓解析锂问题，提升电化学装置的安全性，进而提供性能更优良的电化学装置和电子装置。
附图说明
为了更清楚地说明本申请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申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本申请的一种实施方式的电极组件的结构示意图；
图2为本申请的一种实施方式的电极组件的结构示意图；
图3为本申请的一种实施方式的电极组件的结构示意图；
图4示出了本申请的一种实施方式的电极组件的结构示意图；
图5示出了本申请的另一种实施方式的电极组件的结构示意图；
图6示出了本申请的一种实施方式的电极组件的结构示意图；
图7示出了本申请的一种实施方式的电极组件的结构示意图；
图8示出了本申请的一种电极组件的结构示意图；
图9为本申请的一种制备隔离层的实施方式的示意图。
附图标记：
1：正极集流体；
2：正极活性材料层；
3：隔离层；
4：负极活性材料层；
5：负极集流体；
6：极耳；
7：纳米纤维多孔基体；
8：极耳区
9：拐角区
10：电纺丝装置；
11：电沉积装置：
12：稳压器。
具体实施方式
为使本申请的目的、技术方案、及优点更加清楚明白，以下参照附图和实施例，对本申请进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域技术人员在没有作出创造性劳动前提下所获得的 所有其他实施例，都属于本申请保护的范围。
本申请的电极组件可以是用于电化学装置的任意电极组件，电化学装置可以包括锂离子电池、超级电容器等，以下以锂离子电池的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。
本申请的一个方面提供一种电极组件，其包括电极极片和隔离层，所述电极极片具有极耳，所述隔离层包含纳米纤维多孔基体，所述隔离层在极耳区的孔隙率α2大于其在非极耳非拐角区的孔隙率α1。
在本申请的另一个实施方式中，其中，所述隔离层在极耳区的孔径d2大于其在非极耳非拐角区的孔径d1。
在本申请的另一个实施方式中，其中，所述隔离层在拐角区的孔径d3大于其在非极耳非拐角区的孔径d1；和/或，所述隔离层在拐角区的孔隙率α3大于其在非极耳非拐角区的孔隙率α1。
在本申请的另一个实施方式中，所述隔离层在极耳区的孔径d2与其在非极耳非拐角区的孔径d1之差d2-d1为50nm至3000nm；和/或，所述隔离层在极耳区的孔隙率α2与其在非极耳非拐角区的孔隙率α1之差α2-α1为10％至50％。
在本申请的另一个实施方式中，所述隔离层在拐角区的孔径d3与其在非极耳非拐角区的孔径d1之差d3-d1为50nm至3000nm；和/或，所述隔离层在拐角区的孔隙率α3与其在非极耳非拐角区的孔隙率α1之差α3-α1为10％至50％。
在本申请中，所述极耳区是指整个电极组件靠近极耳5％至60％体积的区域。所述拐角区是指整个电极组件中拐角处的区域。所述非极耳非拐角区是指整个电极组件中除了极耳区和拐角区以外的区域。
电化学装置中电流在膜片区分布不均匀，距离极耳越近，电流密度越大，充电过程中石墨硬膨胀越大，对电解液需求量越大。现有技术中，隔膜的孔隙率分布均匀，因此隔膜的保液量也是均匀的。在电解液需求量大的极耳区，难以保证电解液的需求量。本申请不使用传统的隔膜，而是在电极表面制备纤维隔离层代替传统隔膜。在制备纤维隔离层过程中，通过调控制备工艺参数，使极耳区具有更大的孔径和/或孔隙率，从而提高该区域内的保液量，提高电解液的供给量，从而满足极耳区对电解液的需求。因此，可以实现电化学装置的不同区域具有不同的动力学性能，缓解析锂问题，提升电化学装置的安全性。
卷绕电化学装置拐角区应力集中，电解液保有量较非拐角区低。在电池充放电过程中， 由于拐角区电解液保有量低，导致电解液量供应不足，动力学差，锂离子迁移受阻，容易析锂，提升拐角区的电解液保有量，可以减少拐角区的析锂。本申请使用电极表面的纤维隔离层代替传统隔膜，通过调控纤维隔离层的制备工艺参数，使得拐角区比非极耳非拐角区具有更大的孔径和/或孔隙率，可以使拐角区具有更高的保液量，实现电化学装置的不同区域具有不同的动力学性能，使拐角区的电解液充足，从而提升电化学装置的安全性能。
在本申请的一些实施方式中，其中，所述隔离层孔隙率在不同区域之间是连续变化的或者是不连续变化的；所述隔离层孔径在不同区域之间是连续变化的或者是不连续变化的。
在本申请中，隔离层的孔隙率和孔径在不同区域之间的变化方式可以相同或不同；所述的不连续变化可以为阶梯式变化。
在本申请的一些实施方式中，其中所述纳米纤维多孔基体包含高熔点聚合物纳米纤维和/或低熔点聚合物纳米纤维。
在本申请的一些实施方式中，所述隔离层还包含颗粒填充物，所述颗粒填充物包括高熔点聚合物颗粒、低熔点聚合物颗粒或无机颗粒中的至少一种。
在本申请的一些实施方式中，电极组件具有以下特征中的至少一者：
(a)形成所述高熔点聚合物纳米纤维或高熔点聚合物颗粒的聚合物包括聚偏二氟乙烯、聚酰亚胺、聚酰胺、聚丙烯腈、聚乙二醇、聚氧化乙烯、聚氧化乙烷、聚苯醚、聚碳酸亚丙酯、聚甲基丙烯酸甲酯、聚对苯二甲酸乙二醇酯，聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)或上述物质衍生物中的至少一种，优选聚(偏二氟乙烯-六氟丙烯)、聚偏二氟乙烯、聚丙烯腈、聚甲基丙烯酸甲酯、聚苯醚、聚碳酸亚丙酯、聚氧化乙烷或上述物质的衍生物中的至少一种；
(b)形成所述低熔点聚合物纳米纤维或低熔点聚合物颗粒的聚合物包括聚苯乙烯、聚乙烯、乙烯-丙烯共聚物、乙烯-醋酸乙烯共聚物、丙烯腈-丁二烯-苯乙烯、聚乳酸、聚氯乙烯、聚乙烯丁醛或聚丙烯酸酯中的至少一种；
(c)所述无机颗粒包括HfO 2、SrTiO 3、SnO 2、CeO 2、MgO、NiO、CaO、BaO、ZnO、ZrO 2、Y 2O 3、Al 2O 3、TiO 2、SiO 2、勃姆石、氢氧化镁、氢氧化铝、磷酸锂、锂钛磷酸盐、锂铝钛磷酸盐、锂镧钛酸盐、锂锗硫代磷酸盐、锂氮化物、SiS 2玻璃、P 2S 5玻璃、Li 2O、LiF、LiOH、Li 2CO 3、LiAlO 2、Li 2O-Al 2O 3-SiO 2-P 2O 5-TiO 2-GeO 2陶瓷或石榴石陶瓷中的至少一种；
(d)颗粒填充物的粒径大小为0.001μm至10μm；
(e)所述颗粒填充物的体积占隔离层固体物质总体积的0％至95％。
在本申请中，形成高熔点聚合物纳米纤维或高熔点聚合物颗粒的聚合物熔点通常大于170℃。
在本申请中，形成所述低熔点聚合物颗粒或低熔点聚合物纳米纤维的聚合物的熔点通常为70℃至120℃。在电池的热失控过程中，例如，短路或过充时，低熔点颗粒在较低温度下熔融，封闭隔离层的孔隙，从而停止充放电过程，可以提高电池安全性。
在本申请的隔离层中，颗粒填充物的体积占隔离层固体物质总体积的0％至95％，优选30％至70％。其中，所述隔离层固体物质总体积不包含隔离层中的孔隙的体积。
在本申请的隔离层中，无机颗粒占隔离层固体物质的体积的0％至95％，优选10％至70％。所述隔离层固体物质总体积不包含隔离层中的孔隙的体积。在本申请的隔离层中引入无机颗粒，可以提高隔离层的机械强度，防止隔离层被正负极活性材料颗粒刺穿，提高电池的安全性。
在本申请的一些实施方式中，其中无机颗粒的粒径大小为0.001μm至10μm。
在本申请的一些实施方式中，其中，所述隔离层还具有以下特征中的至少一者：
(a)所述隔离层的孔隙率为20％至95％，优选30％至80％；
(b)所述隔离层的孔径为20nm至30μm，优选50nm至10μm；
(c)所述隔离层的厚度为1μm至20μm，优选5μm至10μm；
(d)所述纳米纤维的直径为0.1nm至5μm，优选0.5nm至1μm。
通过使隔离层的孔隙率范围在上述范围内，可以保证离子传导性能。孔隙率过小，会导致离子传输通路堵塞，阻碍电化学装置正常循环。孔隙率过大，会导致结构不稳定，且机械强度太差，无法抵抗极片表面颗粒的穿刺，容易引发局部正负极短路，造成电性能衰减和严重的自放电问题。
通过使隔离层的孔径范围在上述范围内，可以保证隔离层具有合适的机械强度。孔径过小，会导致离子传输通路不足，阻碍电化学装置正常循环。孔径过大，会导致在孔的位置机械强度太差，无法抵抗极片表面颗粒的穿刺，容易引发局部正负极短路，造成电性能衰减和严重的自放电问题。
通过使隔离层厚度小于或等于20μm、大于或等于1μm，保证等于或小于现有隔膜的厚度，从而有利于提高电化学装置能量密度。
通过使所述纳米纤维直径在上述范围内，可以使隔离层具有合适的孔隙率，提高隔离 层的保液能力，同时保证隔离层具有合适的强度，与分布在隔离层中的颗粒填充物一起提高隔离层的强度，防止隔离层被正负极活性材料颗粒刺穿。
任选地，所述纳米纤维基体和/或颗粒填充物中还可以加入交联剂和引发剂，所述交联剂和引发剂没有特别限制，例如所述交联剂可以包括多异氰酸酯、六甲氧基甲基三聚氰胺、N-羟甲基丙烯酰胺、碳二亚胺、三羟甲基丙烷、氮丙啶、过氧化二异丙苯、丙烯酸丁酯、N,N'-亚甲基双丙烯酰胺、2,5-二甲基-2,5-双(过氧化叔丁基)己烷、双酚A环氧树脂、丙烯酸酯衍生物、含腈基聚合物、苯乙烯、氟乙烯、丙烯腈、丙烯酸胺、醋酸乙烯酯、烷基乙烯基醚、环氧烷烃或氧杂环丁烷衍生物中的至少一种；所述引发剂可以包括氧化苯甲酰、过氧化苯甲酰叔丁酯、过氧化甲乙酮、偶氮二异丁腈、偶氮二异庚腈、偶氮二异丁酸二甲酯、偶氮二异丁基脒盐酸盐、三氟化硼、五氟化磷、四氯化钛、四氯化锡或二氯化锌中的至少一种。
所述隔离层可以形成在电极活性材料层表面。电极活性材料层可以是正极活性材料层和/或负极活性材料层。
所述隔离层可以形成在集流体表面。集流体可以是正极集流体和/或负极集流体。例如在空白极片区内，隔离层直接形成在集流体表面。
所述隔离层可以形成在所述极耳表面。极耳可以是正极极耳和/或负极极耳。
在本申请的一种实施方式中，所述隔离层可以形成在正极极片的一个表面上和负极极片的一个表面上，然后按照负极极片+隔离层、正极极片+隔离层的方式进行叠层，形成电极组件。
在本申请的另一种实施方式中，所述隔离层可以形成在正极极片的两个表面上，然后按照负极极片、隔离层+正极极片+隔离层的方式进行叠层，形成电极组件，其中负极极片表面上没有隔离层。
在本申请的另一种实施方式中，所述隔离层可以形成在负极极片的两个表面上，然后按照隔离层+负极极片+隔离层、正极极片的方式进行层叠，形成电极组件，其中正极极片上没有隔离层。在上述实施方式中形成的电极组件，可以继续按照上述顺序层叠，也可以直接卷绕，形成多层的锂离子电池。
本申请对于层叠方式没有限制，本领域技术人员可以根据实际情况进行选择。
本申请对正极极片没有特别限制，只要能够实现本发明目的即可。例如，所述正极极片通常包含正极集电体和正极活性材料。其中，所述正极集流体没有特别限制，可以为本 领域公知的任何正极集流体，例如铝箔、铝合金箔或复合集流体等。所述正极活性材料没有特别限制，可以为现有技术的任何正极活性材料，所述活性物质包括NCM811、NCM622、NCM523、NCM111、NCA、磷酸铁锂、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂中的至少一种。
任选地，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。例如，所述导电层包括导电剂和粘接剂。
本申请对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。其中，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、铜合金箔或复合集流体等。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，可以包括石墨、硅、或硅碳等中的至少一种。
任选地，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。例如，所述导电层包括导电剂和粘接剂。
上述正极极片和负极极片所用的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。例如，导电剂可选用导电炭黑(Super P)。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(Na-CMC)等中的至少一种。例如，粘接剂可选用丁苯橡胶(SBR)。
本申请还提供一种电化学装置，其包含本申请的电极组件。例如，所述电化学装置为锂离子电池。
本申请对锂离子电池的电解液没有特别限制，可以使用本领域公知的任何电解液，所述电解液可以是凝胶态、固态和液态中的任一种。例如，液态电解液包括锂盐和非水溶剂。
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等中的至少一种。例如，锂盐可选用LiPF 6。
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、腈化合物或其它有机溶剂等中的至少一种。
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-甲基亚乙酯或碳酸三氟甲基亚乙酯等中的至少一种。
本申请对于制备上述电极组件的方法不做额外限定，可以采用本领域已知的任意方法进行制备。例如，所述纳米纤维多孔基体可以通过电纺丝、气纺丝、离心纺丝、电吹法、熔喷法、闪蒸法、涂布法等工艺制备而成；所述颗粒填充物可以通过电沉积法、印刷法、涂布法、旋转法、浸渍法等工艺制备而成。
沉积纳米纤维多孔基体和颗粒填充物的顺序没有特别限制，只要能够形成本申请的隔离层即可。例如，所述纳米纤维多孔基体和颗粒填充物可以同时沉积或者交替沉积。
所述纳米纤维多孔基体可以用本领域已知的任何纺丝设备实施，没有特别限制，只要能实现本申请目的即可，可以使用本领域已知的任何纺丝设备，例如电纺丝设备可以为永康乐业Elite系列等；气纺丝设备可以为南京捷纳思新材料的气喷纺丝机等；离心纺丝设备可以为四川致研科技的离心纺丝机等。所述电沉积法可以用本领域已知的任何设备实施，没有特别限制，只要能实现本申请的目的即可。例如可以使用法国萨麦斯的静电喷涂设备。
图1示出了本申请的一种实施方式的电极组件结构示意图。其中，在电极极片的一个表面上设置了隔离层。隔离层3涂覆在正极活性材料层2上，且夹设在正极活性材料层2和负极活性材料层4之间，所述正极活性材料层涂覆在正极集流体1上，所述负极活性材料层涂覆在负极集流体5上；
图2示出了本申请的一种实施方式的电极组件结构示意图，其中，在正极极片的两个表面均设置了隔离层。两个隔离层3分别涂覆于两个正极活性材料层2上，其中一个隔离层夹设于正极活性材料层2和负极活性材料层4之间，所述正极活性材料层涂覆在正极集流体1的两个表面上，所述负极活性材料层涂覆在负极集流体5的两个表面上；
图3示出了本申请的一种实施方式的电极组件结构示意图，其中，在负极极片的两个表面均设置了隔离层。两个隔离层3分别涂覆于两个负极活性材料层4上，其中一个隔离层夹设于正极活性材料层2和负极活性材料层4之间，所述正极活性材料层涂覆在正极集 流体1的两个表面上，所述负极活性材料层涂覆在负极集流体5的两个表面上；
图4示出了本申请的一种实施方式的电极组件的结构示意图，其中，示出了极耳6和纳米纤维多孔基体7，极耳区8的纳米纤维多孔基体的孔隙率大于非极耳区的纳米纤维多孔基体的孔隙率；
图5示出了本申请的另一种实施方式的电极组件的结构示意图，其中，示出了极耳6和纳米纤维多孔基体7，极耳区8的纳米纤维多孔基体的孔径大于非极耳区的纳米纤维多孔基体的孔径；
图6示出了本申请的另一种实施方式的电极组件的结构示意图，其中，示出了两个极耳6和纳米纤维多孔基体7，极耳区8的纳米纤维多孔基体的孔径大于非极耳区的纳米纤维多孔基体的孔径；
图7示出了本申请另一种实施方式的电极组件的结构示意图，其中，示出了极耳6、隔离层3、正极活性材料层2，极耳区的纳米纤维多孔基体的孔隙率大于非极耳区的纳米纤维多孔基体的孔隙率；
图8示出了本申请另一种实施方式的电极组件的结构示意图，其中，示出了极耳6，极耳区8，以及拐角区9。
图9为本申请的一种制备隔离层的实施方式的示意图，其中，电纺丝装置10和电沉积装置11分别将纤维和聚合物颗粒沉积在电极表面上；电纺丝装置10和电沉积装置11均连接在稳压器12上。
本申请还提供一种电子装置，其包含本申请的电化学装置。
本申请所述的电子装置包括本领域一般的电子装置，例如笔记本电脑、手机、电动摩托车、电动汽车、电动玩具等。
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。
具体地，在本申请中，以下术语的含义如下：
聚合物颗粒的平均粒径：聚合物颗粒的平均粒径用体积基准的D50表示，即粒径在D50以下的聚合物颗粒体积含量占全部颗粒的50％。
无机颗粒的平均粒径：无机颗粒的平均粒径用体积基准的D50表示，即粒径在D50以下的无机颗粒体积含量占全部颗粒的50％。
测试方法：
锂离子电池析锂表征：
15℃下，锂离子电池先使用1C倍率充电，然后满充至截止电压，以0.7C倍率放电至截止电压，以此测试流程循环15圈后，锂离子电池再以1C电流满充，结束充电流程。
电池满充后，进行拆解，观察负极表面靠近极耳区域是否存在灰白色或白色固体物质，若无，表明锂离子电池未析锂，锂离子电池正常；如有，则表明锂离子电池存在析锂现象，存在安全风险。
50个充放电循环后的放电容量/首次放电容量(％)：
将锂离子电池以0.5C的电流恒定电流充电至4.4V，然后以4.4V的电压恒定电压充电至电流为0.05C，在25℃±3℃的环境中静置10min，然后以0.5C的电流放电至3.0V，记录首次放电容量为Q 1，如此重复循环50次，记录此时放电容量为Q 50，通过如下公式得到50次循环后的容量保持率η：η＝Q 50/Q 1*100％。
实施例
制备例1：负极极片的制备
将负极活性材料石墨(Graphite)、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(H 2O)作为溶剂，调配成为固含量为0.7的浆料，并搅拌均匀。将浆料均匀涂覆在厚度为8μm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130μm的单面涂布负极活性材料的负极极片。在该负极极片的另一个表面上重复以上步骤，得到双面涂布负极活性材料的负极极片。然后，将极片裁切成(41mm×61mm)的规格待用。
制备例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，调配成为固含量为0.75的浆料，并搅拌均匀。将浆料均匀涂覆在厚度为10μm的正极集流体铝箔的一个表面上，90℃条件下烘干，得到涂层厚度为110μm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，得到双面涂布完成的正极极片。涂布完成后，将极片裁切成(38mm×58mm)的规格待用。
制备例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1.15M的电解液。
以下实施例举例说明根据本申请的纳米纤维多孔基体的隔离层的制备。这些实施例以正极极片为例进行说明，并且在正极极片的两个表面上沉积一体化隔离层。应当理解，所述一体化隔离层也可以沉积在负极极片的两个表面上，或者在正极极片的一个表面上和负极极片的一个表面上分别沉积一层一体化隔离层，这些实施方式同样可以实现本申请的目的。本领域技术人员，应当理解，这些实施方式同样在本申请的保护范围内。
实施例1
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，制备纳米纤维，其中，纳米纤维的直径为100nm，纺丝量为5.0g/m 2，极耳区和拐角区的隔离层的平均孔径为600nm，孔隙率为50％；非极耳非拐角区的隔离层平均孔径为500nm，纺丝量为5.1g/m 2；孔隙率为50％，隔离层的厚度为10μm。
以上步骤完成后，即已完成正极极片的单面涂布。之后，在正极极片的另一个表面上重复以上步骤，并在40℃条件下真空烘干去除DMF等分散剂，随后升高温度至80℃热处理6h以完成交联过程，即可得到双面涂布隔离层的正极极片。
实施例2
除了极耳区和拐角区隔离层的平均孔径为1000nm、纺丝量为4.7g/m 2以外，其余与实施例1相同。
实施例3
除了极耳区和拐角区隔离层的平均孔径为3000nm、纺丝量为3.5g/m 2以外，其余与实 施例1相同。
实施例4
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，制备厚度为10μm的纳米纤维多孔基体。其中，所采用的纳米纤维的直径为100μm；
极耳区和拐角区的隔离层的平均孔径为500nm，纺丝量为5.1g/m 2，非极耳非拐角区的隔离层平均孔径为500nm，纺丝量为5.1g/m 2；
极耳区和拐角区的隔离层的平均孔隙率为60％，非极耳非拐角区的隔离层的平均孔隙率为50％。
实施例5
除了极耳区和拐角区的隔离层的平均孔隙率为70％，纺丝量为4.9g/m 2以外，其余与实施例4相同。
实施例6
除了极耳区和拐角区的隔离层的平均孔隙率为80％，纺丝量为4.6g/m 2以外，其余与实施例4相同。
实施例7
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，制备厚度为10μm的纳米纤维多孔基体。其中，所采用的纳米纤维的直径为100μm；
极耳区和拐角区的隔离层的平均孔径为600nm，纺丝量为4.7g/m 2，非极耳非拐角区的隔离层平均孔径为500nm，纺丝量为5.3g/m 2；
极耳区和拐角区的隔离层的平均孔隙率为70％，非极耳非拐角区的隔离层的平均孔隙率为30％。
实施例8
除极耳区和拐角区的隔离层的平均孔隙率为70％、纺丝量为4.7g/m 2、非极耳非拐角区的孔隙率为40％、纺丝量为为5.2g/m 2以外，其余与实施例7相同。
实施例9
除极耳区和拐角区的隔离层的平均孔隙率为70％、纺丝量为4.7g/m 2、非极耳非拐角区的孔隙率为40％、纺丝量为为5.2g/m 2以外，其余与实施例7相同。
实施例10
除极耳区和拐角区的隔离层平均孔径为1000nm、平均孔隙率为70％、纺丝量为4.3g/m 2、非极耳非拐角区的孔隙率为50％、纺丝量为为5.1g/m 2以外，其余与实施例7相同。
实施例11
除极耳区和拐角区的隔离层平均孔径为800nm、平均孔隙率为65％、纺丝量为4.5g/m 2，非极耳非拐角区的隔离层的平均孔隙率为50％、纺丝量为为5.1g/m 2以外，其余与实施例7相同。
实施例12
除极耳区和拐角区的隔离层平均孔径为600nm、平均孔隙率为60％、纺丝量为4.7g/m 2，非极耳非拐角区的隔离层的平均孔隙率为50％、纺丝量为为5.1g/m 2以外，其余与实施例7相同。
实施例13
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，制备一层厚度为10μm的纳米纤维多孔基体。其中，所采用的纳米纤维的直径为100μm；
极耳区的隔离层的平均孔径为900nm，平均孔隙率为63％，纺丝量为4.5g/m 2，拐角区的隔离层的平均孔径为700nm，平均孔隙率为73％，纺丝量为4.4g/m 2，非极耳非拐角区的隔离层平均孔径为500nm，平均孔隙率为50％，纺丝量为5.1g/m 2。
实施例14
除极耳区平均孔径为850nm、平均孔隙率为67％、纺丝量为4.5g/m 2，拐角区的隔离层平均孔径为750nm、平均孔隙率为68％、纺丝量为4.5g/m 2以外，其余与实施例13相同。
实施例15
除极耳区平均孔径为760nm、平均孔隙率为70％、纺丝量为4.2g/m 2，拐角区的隔离层平均孔径为800nm、平均孔隙率为66％、纺丝量为4.3g/m 2以外，其余与实施例13相同。
实施例16
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；将聚乙烯(PE)颗粒分散在N-甲基吡咯烷酮(NMP)/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为40％的悬浊液B。
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，制备厚度为20μm的纳米纤维多孔基体。在纺丝的同时，利用电喷涂的方法将聚乙烯颗粒同 步喷涂，聚乙烯颗粒以填充方式分布在纤维多孔基体中。
其中，所采用的纳米纤维的直径为100μm，极耳区和拐角区的隔离层的平均孔径为600nm，纺丝量为9.9g/m 2；孔隙率为70％；非极耳非拐角区的隔离层平均孔径为500nm，平均孔隙率为50％，纺丝量为9.7g/m 2；聚乙烯(PE)颗粒的平均粒径为500nm，聚乙烯(PE)颗粒占整个隔离层固体物质总体积的60％，所述隔离层固体物质总体积不包含隔离层中的孔隙的体积。
以上步骤完成后，即已完成正极极片的单面涂布。之后，在正极极片的另一个表面上重复以上步骤，并在40℃条件下真空烘干去除DMF等分散剂，随后升高温度至80℃热处理6h以完成交联过程，即可得到双面涂布隔离层的正极极片。
实施例17
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，制备厚度为10μm的纳米纤维多孔基体。其中，所采用的纳米纤维的直径为100μm，极耳区的隔离层的平均孔径为850nm，纺丝量为4.5g/m 2；孔隙率为67％；拐角区的隔离层的平均孔径为750nm，纺丝量为4.5g/m 2；孔隙率为68％。
非极耳非拐角区的隔离层平均孔径为500nm，平均孔隙率为50％，纺丝量为4.3g/m 2；
在纺丝的同时，将无机颗粒勃姆石分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为40％的悬浊液B作为原料，利用电喷涂的方法将无机颗粒同步喷涂，勃姆石以填充方式分布在纤维多孔基体中。其中，勃姆石颗粒的平均粒径为500nm，勃姆石占整个隔离层固体物质总体积的10％，所述隔离层固体物质总体积不包含隔离层中的孔隙的体积。
以上步骤完成后，即已完成正极极片的单面涂布。之后，在正极极片的另一个表面上重复以上步骤，并在40℃条件下真空烘干去除DMF等分散剂，随后升高温度至80℃热处理6h以完成交联过程，即可得到双面涂布隔离层的正极极片。
实施例18
除了非极耳非拐角区的纺丝量为为4.1g/m 2、勃姆石占整个隔离层固体物质总体积的50％以外，其余与实施例17相同。
实施例19
除了非极耳非拐角区的纺丝量为为3.8g/m 2、勃姆石占整个隔离层固体物质总体积的70％以外，其余与实施例17相同。
实施例20
除了非极耳非拐角区的纺丝量为为3.8g/m 2、勃姆石颗粒的平均粒径为200nm、勃姆石占整个隔离层固体物质总体积的50％以外，其余与实施例17相同。
实施例21
除了非极耳非拐角区的纺丝量为为3.8g/m 2、勃姆石颗粒的平均粒径为1000nm、勃姆石占整个隔离层固体物质总体积的50％以外，其余与实施例17相同。
实施例22
负极极片的制备
按照制备例1完成负极极片的制备。
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；
在制备例2的正极极片的一个表面上，利用溶液A作为原料，通过电纺丝的方法，通过电纺丝的方法，制备厚度为10μm的纳米纤维多孔基体。其中，所采用的纳米纤维的直径为100nm，极耳区的隔离层的平均孔径为850nm，孔隙率为67％，纺丝量为4.5g/m 2；拐角区的隔离层的平均孔径为750nm，孔隙率为68％，纺丝量为4.5g/m 2。
非极耳非拐角区的隔离层平均孔径为500nm，纺丝量为5.1g/m 2；孔隙率为50％，隔离层的厚度为10μm。
以上步骤完成后，即已完成正极极片的单面涂布。之后，在正极极片的另一个表面上重复以上步骤，并在40℃条件下真空烘干去除DMF等分散剂，随后升高温度至80℃热处理6h以完成交联过程，即可得到双面涂布隔离层的正极极片。
实施例23
除了非极耳非拐角区的隔离层平均孔径为500nm，纺丝量为9.8g/m 2；孔隙率为50％，隔离层的厚度为20μm以外，其余与实施例22相同。
锂离子电池制备
将各实施例制备的的正极极片和制备例1中所制备的负极极片相对叠好并卷绕成电极组件。卷绕结构收尾处、极耳处，阴极头部区域贴胶后，置入铝塑膜中，经顶侧封、注入制备例3的电解液、封装后，最终得到锂离子电池。
对比例1
采用厚度为15μm的聚乙烯(PE)作为隔离膜，放置于制备例1中的负极极片和制备例2中的正极极片之间作为隔离膜，将负极极片、正极极片和隔离膜相对叠好并卷绕成电极组件。卷绕结构收尾处、极耳处，阴极头部区域贴胶后，置入铝塑膜中，经顶侧封、注入制备例3的电解液、封装后，最终得到锂离子电池。
对比例2
正极极片的制备
将95％的PVDF，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为25％的溶液A；同时将95％的勃姆石，4.5％丙烯腈和0.5％三氟化硼分散在DMF/丙酮(7:3)溶剂中，并搅拌均匀至浆料粘度稳定，得到质量分数为40％的悬浊液B。
在制备例2的正极极片的一个表面上，利用溶液A作为原料通过电纺丝和气纺丝混合使用的方法，制备厚度为10μm的PVDF无纺布隔离层，隔离层平均孔径为500nm，孔隙率为80％。
以上步骤完成后，即已完成正极极片的单面涂布。之后，在正极极片的另一个表面上 重复以上步骤，并在40℃条件下真空烘干去除DMF等分散剂，随后升高温度至80℃热处理6h以完成交联过程，即可得到双面涂布隔离层的正极极片。将制备例1中的负极极片和以上制得的带有隔离层的正极极片相对叠好并卷绕成电极组件。卷绕结构收尾处、极耳处，阴极头部区域贴胶后，置入铝塑膜中，经顶侧封、注入制备例3的电解液、封装后，最终得到锂离子电池。
对比例3
除了非极耳非拐角区的纺丝量为1.1g/m 2，隔离层的厚度为1μm以外，其余与实施例22相同。
将制备例1中的负极极片和对比例3制得的正极极片相对叠好并卷绕成电极组件。卷绕结构收尾处、极耳处，阴极头部区域贴胶后，置入铝塑膜中，经顶侧封、注入制备例3的电解液、封装后，最终得到锂离子电池。
实施例1-23、对比例1-3的数据和测试结果见表1和表2。
Figure PCTCN2020081798-appb-000001
PP204589PCT
Figure PCTCN2020081798-appb-000002
表2
Figure PCTCN2020081798-appb-000003
从表1和表2中可以看出，与现有技术的普通隔膜相比，本申请所提供的电极组件通过调控隔离层孔径或孔隙率的不均匀分布，使得极耳区和/或拐角区的孔隙率和/或孔径更大，保液量更大，从而满足极片不同区域不同的保液量需求。通过提升极耳区和拐角区的 保液量，实现极片不同区域具有不同的动力学性能，再通过改进隔离层的厚度，可以进一步缓解电化学装置析锂问题，特别是极耳区和拐角区的析锂问题，提升电化学装置安全性。
以上所述仅为本申请的较佳实施例，并非用于限定本申请的保护范围。凡在本申请的精神和原则之内所作的任何修改、等同替换、改进等，均包含在本申请的保护范围内。

Claims (14)

  1. 一种电极组件，其包括电极极片和隔离层，所述电极极片具有极耳，所述隔离层包含纳米纤维多孔基体，所述隔离层在极耳区的孔隙率α2大于其在非极耳非拐角区的孔隙率α1。
  2. 根据权利要求1所述的电极组件，其中，所述隔离层在极耳区的孔径d2大于其在非极耳非拐角区的孔径d1。
  3. 根据权利要求1所述的电极组件，其中，所述隔离层在拐角区的孔径d3大于其在非极耳非拐角区的孔径d1；和/或，所述隔离层在拐角区的孔隙率α3大于其在非极耳非拐角区的孔隙率α1。
  4. 根据权利要求1所述的电极组件，其中，所述隔离层在极耳区的孔径d2与其在非极耳非拐角区的孔径d1之差d2-d1为50至3000nm；
    和/或，所述隔离层在极耳区的孔隙率α2与其在非极耳非拐角区的孔隙率α1之差α2-α1为10％至50％。
  5. 根据权利要求1所述的电极组件，其中，所述隔离层在拐角区的孔径d3与其在非极耳非拐角区的孔径d1之差d3-d1为50至3000nm；和/或，所述隔离层在拐角区的孔隙率α3与其在非极耳非拐角区的孔隙率α1之差α3-α1为10％至50％。
  6. 根据权利要求1所述的电极组件，其中，所述隔离层的孔隙率在相邻区域之间是连续变化的或者是不连续变化的；所述隔离层的孔径在相邻区域之间是连续变化的或者是不连续变化的。
  7. 根据权利要求1所述的电极组件，其中所述纳米纤维多孔基体包含高熔点聚合物纳米纤维和/或低熔点聚合物纳米纤维。
  8. 根据权利要求1所述的电极组件，其中，所述隔离层还包含颗粒填充物，所述颗粒填充物包括高熔点聚合物颗粒、低熔点聚合物颗粒或无机颗粒中的至少一种。
  9. 根据权利要求8所述的电极组件，其中所述纳米纤维基体和/或颗粒填充物中还包含交联剂和引发剂。
  10. 根据权利要求9的所述的电极组件，其中，所述交联剂包括多异氰酸酯、六甲氧基甲基三聚氰胺、N-羟甲基丙烯酰胺、碳二亚胺、三羟甲基丙烷、氮丙啶、过氧化二异丙苯、丙烯酸丁酯、N,N'-亚甲基双丙烯酰胺、2,5-二甲基-2,5-双(过氧化叔丁基)己烷、双酚A 环氧树脂、丙烯酸酯衍生物、含腈基聚合物、苯乙烯、氟乙烯、丙烯腈、丙烯酸胺、醋酸乙烯酯、烷基乙烯基醚、环氧烷烃或氧杂环丁烷衍生物中的至少一种；
    所述引发剂包括氧化苯甲酰、过氧化苯甲酰叔丁酯、过氧化甲乙酮、偶氮二异丁腈、偶氮二异庚腈、偶氮二异丁酸二甲酯、偶氮二异丁基脒盐酸盐、三氟化硼、五氟化磷、四氯化钛、四氯化锡或二氯化锌中的至少一种。
  11. 根据权利要求8所述的电极组件，其中，具有以下特征中的至少一者：
    (a)形成所述高熔点聚合物纳米纤维或高熔点聚合物颗粒的聚合物包括聚偏二氟乙烯、聚酰亚胺、聚酰胺、聚丙烯腈、聚乙二醇、聚氧化乙烯、聚氧化乙烷、聚苯醚、聚碳酸亚丙酯、聚甲基丙烯酸甲酯、聚对苯二甲酸乙二醇酯，聚(偏二氟乙烯-六氟丙烯)、聚(偏二氟乙烯-共-三氟氯乙烯)或上述物质衍生物中的至少一种，优选聚(偏二氟乙烯-六氟丙烯)、聚偏二氟乙烯、聚丙烯腈、聚甲基丙烯酸甲酯、聚苯醚、聚碳酸亚丙酯、聚氧化乙烷或上述物质的衍生物中的至少一种；
    (b)形成所述低熔点聚合物纳米纤维或低熔点聚合物颗粒的聚合物包括聚苯乙烯、聚乙烯、乙烯-丙烯共聚物、乙烯-醋酸乙烯共聚物、丙烯腈-丁二烯-苯乙烯、聚乳酸、聚氯乙烯、聚乙烯丁醛或聚丙烯酸酯中的至少一种；
    (c)所述无机颗粒包括HfO 2、SrTiO 3、SnO 2、CeO 2、MgO、NiO、CaO、BaO、ZnO、ZrO 2、Y 2O 3、Al 2O 3、TiO 2、SiO 2、勃姆石、氢氧化镁、氢氧化铝、磷酸锂、锂钛磷酸盐、锂铝钛磷酸盐、锂镧钛酸盐、锂锗硫代磷酸盐、锂氮化物、SiS 2玻璃、P 2S 5玻璃、Li 2O、LiF、LiOH、Li 2CO 3、LiAlO 2、Li 2O-Al 2O 3-SiO 2-P 2O 5-TiO 2-GeO 2陶瓷或石榴石陶瓷中的至少一种；
    (d)颗粒填充物的粒径大小为0.001μm至10μm；
    (e)所述颗粒填充物的体积占隔离层固体物质总体积的0％至95％。
  12. 根据权利要求1所述的电极组件，其中，所述隔离层还具有以下特征中的至少一者：
    (a)所述隔离层的孔隙率为30％至95％；
    (b)所述隔离层的孔径为20nm至30μm；
    (c)所述隔离层的厚度为1μm至20μm；
    (d)所述纳米纤维的直径为0.1nm至5μm。
  13. 一种电化学装置，其包含权利要求1-12中任一项所述的电极组件。
  14. 一种电子装置，其包含权利要求13所述的电化学装置。
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CN114243122A (zh) * 2021-12-08 2022-03-25 宁德新能源科技有限公司 电化学装置及用电装置
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CN116344741B (zh) * 2023-05-26 2023-08-08 深圳市德兰明海新能源股份有限公司 正极极片、二次电池以及用电装置

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