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WO2022198644A1 - 一种多孔碳集流体及电化学装置 - Google Patents

一种多孔碳集流体及电化学装置 Download PDF

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Publication number
WO2022198644A1
WO2022198644A1 PCT/CN2021/083314 CN2021083314W WO2022198644A1 WO 2022198644 A1 WO2022198644 A1 WO 2022198644A1 CN 2021083314 W CN2021083314 W CN 2021083314W WO 2022198644 A1 WO2022198644 A1 WO 2022198644A1
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Prior art keywords
current collector
porous carbon
carbon current
polymer
porous
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PCT/CN2021/083314
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English (en)
French (fr)
Inventor
李志愿
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宁德新能源科技有限公司
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Priority to CN202180002681.3A priority Critical patent/CN114026717B/zh
Priority to PCT/CN2021/083314 priority patent/WO2022198644A1/zh
Publication of WO2022198644A1 publication Critical patent/WO2022198644A1/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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/666—Composites in the form of mixed materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/663—Selection of materials containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the field of energy storage, in particular to a porous carbon current collector and an electrochemical device.
  • the current collectors of lithium-ion batteries are mainly copper foil and aluminum foil, which are the heaviest part of the battery except for the positive and negative electrode materials, and the metal material has poor flexibility, so it is not suitable for flexible electrodes.
  • flexible substrates for bendable flexible lithium-ion batteries There are two main types of flexible substrates for bendable flexible lithium-ion batteries:
  • Non-conductive flexible substrates such as polymers, paper, and woven fabrics.
  • Conductive flexible substrate mainly using carbon material films such as graphene or carbon nanotubes as the flexible substrate, and the active material is attached to its structural unit to form a flexible electrode. It has obvious advantages in quality and is the mainstream development direction of flexible batteries with high energy density and light weight.
  • the purpose of the present application is to prepare a porous carbon current collector that can improve the rate performance of a battery, as well as electrochemical devices and electronic devices comprising the porous carbon current collector.
  • the present application provides a porous carbon current collector comprising a carbon material and a polymer, wherein the porous carbon current collector has a porosity of 9% to 60%.
  • the porous carbon current collector satisfies at least one of the following features (1) to (3): (1) the pore size of the porous carbon current collector ranges from 0.02 ⁇ m to 1 ⁇ m; (2) ) the air permeability of the porous carbon current collector is 100s/100cc to 500s/100cc; (3) the volume of pores with a pore size ranging from 0.03 ⁇ m to 0.2 ⁇ m in the porous carbon current collector accounts for 80% of the total pore volume % to 100%.
  • the mass content of the carbon material is 40% to 90%, and the mass content of the polymer is 10% to 60%.
  • the polymer satisfies at least one of the following features (4) to (8): (4) the melting point of the polymer ranges from 130°C to 200°C; (5) the The weight average molecular weight of the polymer ranges from 150,000 to 1,000,000; (6) the melt index of the polymer is 0.3g/10min to 20g/10min; (7) The liquid absorption rate of the polymer in the electrolyte is less than 5%; (8) The film stretch rate of the polymer is -5% to 5%.
  • the thickness of the porous carbon current collector is 3 ⁇ m to 30 ⁇ m.
  • the carbon material includes at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, or carbon fibers.
  • the polymer comprises polyethylene, polypropylene, polymethyl methacrylate, polyamide, polyvinyl alcohol, polyoxymethylene, polyimide, ethylene-vinyl acetate copolymer or polyvinylidene At least one of vinyl fluoride.
  • the porous carbon current collector satisfies at least one of the following features (9) to (12): (9) the electrical resistance of the porous carbon current collector is 3 m ⁇ to 100 m ⁇ ; (10) the The strength of the porous carbon current collector is 100MPa to 500MPa; (11) After the porous carbon current collector is baked at 120°C for 15 minutes, the resistance is more than 98% of the initial resistance, and the strength is more than 98% of the initial strength; (12) The elongation of the porous carbon current collector is 2% to 10%.
  • At least one surface of the porous carbon current collector is further provided with a metal layer.
  • the ratio of the projected area of the metal layer on the surface of the porous carbon current collector to the area of the porous carbon current collector is 5% to 70%.
  • the thickness of the metal layer is 0.2 ⁇ m to 2 ⁇ m.
  • the metal in the metal layer includes at least one of copper, aluminum, gold, silver or nickel.
  • the present application provides an electrochemical device comprising the porous carbon current collector as described in the first aspect of the present application.
  • the present application provides an electronic device comprising the electrochemical device according to the second aspect of the present application.
  • the present application provides a porous carbon current collector, the porous carbon current collector includes a carbon material and a polymer, and the porous carbon current collector has a porosity of 9% to 60%.
  • the porous carbon current collector of the present application has a specific porous structure, so that the current collector has a certain liquid retention capacity, overcomes the disadvantage of poor high-power performance of the existing flexible lithium-ion battery, and improves the rate and low-temperature performance of the lithium-ion battery.
  • 1 is a schematic diagram of a current collector according to an embodiment of the present application, wherein 1 represents a carbon material and 2 represents a polymer.
  • FIG. 2 is a SEM image of a cross-section of a current collector according to an embodiment of the present application.
  • a first aspect of the present application provides a porous carbon current collector including a carbon material and a polymer, and the porous carbon current collector has a porosity of 9% to 60%. Porosity is contributed by gaps between polymers or between polymers and carbon materials or between carbon materials and carbon materials.
  • the increase of the porosity of the current collector and the improvement of the liquid retention capacity are beneficial to the improvement of the charge-discharge capacity retention rate and the low-temperature capacity retention rate.
  • the porosity is too high, the mechanical properties of the current collector will deteriorate, resulting in a decrease in its strength, which is not conducive to the subsequent coating cold pressing. and other processing.
  • the carbon material as the current collector can improve the flexibility and energy density of the electrode, and the prepared electrode sheet is suitable for batteries for flexible electronic devices.
  • the porous carbon current collector of the present application has a specific porous structure, so that the current collector has a certain liquid-holding capacity, thereby improving the rate and low-temperature performance of the lithium-ion battery.
  • the porous carbon current collector has a porosity of 10%, 15%, 18%, 25%, 28%, 30%, 35%, 38%, 40%, 45%, 18%, 52% %, 56% or 60%.
  • the porous carbon current collector has a pore size ranging from 0.02 ⁇ m to 1 ⁇ m.
  • the volume of pores with a pore size ranging from 0.03 ⁇ m to 0.2 ⁇ m in the porous carbon current collector is 80% to 100% of the total pore volume, such as 80%, 85%, 90%, 95% %, 98%, etc.
  • the pore size of the porous carbon current collector meets the above range, which can reduce the adverse effect of the existence of the current collector pore structure on the mechanical properties of the current collector.
  • the pore distribution is more uniform. , so that the structure of the current collector is uniform, which further ensures the improvement of the electrical performance, and is also conducive to the improvement of the mechanical performance of the current collector and avoids the poor processing process.
  • the porous carbon current collector has an air permeability of 100s/100cc to 500s/100cc.
  • the porous carbon current collector consists of a carbon material and a polymer.
  • the mass content of the carbon material is 40% to 90% based on the total mass of the porous carbon current collector. Since the polymer does not have electrical conductivity, an increase in the content will increase the resistance of the current collector, which is not conducive to electron conduction, and the polymer content is preferably not more than 60%. In some embodiments, the mass content of the polymer is 10% to 60% based on the total mass of the porous carbon current collector.
  • the polymer has a melting point in the range of 130°C to 200°C. In some embodiments, the polymer has a melting point in the range of 130 to 150°C, 150 to 180°C, or 180 to 200°C.
  • the melting point of the polymer is too low, so that the processing temperature range that the current collector can withstand is limited, which is not conducive to the dimensional stability of the current collector and the fabrication and processing of lithium ion batteries.
  • the melting point of the polymer is too high, which makes it difficult to melt and process the current collector, and is not conducive to the stability of the pore-forming agent added during the current collector manufacturing process.
  • the polymer has a weight average molecular weight in the range of 150,000 to 1 million, such as 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, and the like.
  • the molecular weight of the polymer is too low, which will lead to weak intermolecular forces and enhanced molecular chain mobility, thereby reducing the melting point of the polymer, increasing the melt index, decreasing the mechanical properties, and weakening the dimensional stability. It is difficult to ensure the preparation and processing of the current collector itself. Process stability and current collector stability during slurry coating.
  • the molecular weight of the polymer is too large, on the one hand, the synthesis process is difficult, and it is difficult to find a suitable polymer for use; Pore structure.
  • the polymer has a melt index of 0.3g/10min to 20g/10min, eg, 0.3g/10min, 1.0g/10min, 1.5g/10min, 2.0g/10min, 3.0g/10min, 4.0 g/10min, 5.0g/10min, 6g/10min, 10g/10min, etc.
  • the polymer is required to have a certain melt processing capability.
  • the melt index of the polymer reflects the melt processing ability to a certain extent. The higher the melt index, the stronger the flow ability of the polymer at high temperature, and it is difficult to prepare a dimensionally stable composite film. The lower the melt index, the weaker the flow ability of the melt, which is difficult to pass through Melt processing.
  • the polymer has a liquid uptake of less than 5% in the electrolyte.
  • the liquid absorption rate of the polymer in the electrolyte represents the weight change rate after immersing the polymer film (the thickness of the film can be in the range of 10 ⁇ m to 15 ⁇ m) in the electrolyte or the electrolyte solvent,
  • the calculation formula can be (m2-m1)/m1, where m1 represents the weight of the adhesive film before dipping, and m2 represents the weight of the adhesive film after dipping.
  • the immersion time may be 48h-96h (eg 72h), and the immersion temperature may be 70°C-90°C (eg 85°C).
  • the porous structure of the current collector plays a role in retaining liquid during use, and the polymer component in it needs to have a certain resistance to electrolyte to avoid the size change, conductive network structure change, and mechanical properties change of the current collector caused by liquid absorption expansion.
  • the structure of the current collector is kept stable during the use of the cell.
  • the electrolyte solvent used in testing the liquid absorption rate is EC and DMC, and the specific mass ratio may be 1/1.
  • the polymer has a film stretch of -5% to 5%.
  • the stretch rate of the polymer film refers to the change rate of the film length after the polymer film is stretched along the length direction of the film, and the calculation formula can be (L2-L1)/L1, where L1 represents The length of the film before stretching, L2 represents the length of the film after stretching. Since the coating and drying temperature is generally within 90°C to 110°C when the current collector of the present application is used to coat the positive and negative electrode slurry, the current collector should have good dimensional stability within 110°C to avoid coating Process abnormality in processing due to thermal contraction or expansion of the current collector. In some embodiments, the polymer has a film stretch of -5% to 0%.
  • the polymer film stretch is 0% to -5%. Therefore, the film stretch ratio of the polymer is required to be -5% to 5%.
  • the test conditions for the stretch rate of the adhesive film of the polymer include: the temperature is in the range of 90° C. to 110° C., the thickness of the adhesive film is in the range of 10 ⁇ m to 15 ⁇ m, and the stretching is performed with a force of 5g-10g , the stretching time is 10min to 30min.
  • the test conditions for the stretch rate of the adhesive film of the polymer include: the temperature is 110° C., the thickness of the adhesive film is 10 ⁇ m to 15 ⁇ m, the stretching is performed with a force of 5 g, and the stretching time is 20 minutes.
  • the polymer comprises polyethylene, polypropylene, polymethyl methacrylate, polyamide, polyvinyl alcohol, polyoxymethylene, polyimide, ethylene vinyl acetate, polyvinylidene fluoride at least one of.
  • the porous carbon current collector has a thickness of 3 ⁇ m to 30 ⁇ m.
  • the increase in the thickness of the current collector has no effect on the mechanical properties, and the electrolyte retention increases to a certain extent, but has little effect on the performance; considering that the increase in the thickness of the current collector will lose the volumetric energy density, it is preferably not more than 30 ⁇ m.
  • the thickness of the porous carbon current collector is 3 ⁇ m, 8 ⁇ m, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, or 30 ⁇ m, or the like.
  • the carbon material includes at least one of conductive carbon black, acetylene black, graphite, graphene, carbon nanotubes, or carbon fibers.
  • the carbon material plays a conductive role, and there are no special requirements for the type.
  • the carbon material preferably has a D50 of 30 nm to 500 nm and a specific surface area of 5 m 2 /g to 300 m 2 /g.
  • the carbon material is a carbon nanotube, preferably, the diameter of the tube is 20 nm to 50 nm, and the tube length is 0.5 ⁇ m to 5 ⁇ m.
  • the carbon material has a specific surface area of 100 m 2 /g to 300 m 2 /g.
  • the electrical resistance of the porous carbon current collector is 3 m ⁇ to 100 m ⁇ .
  • the strength of the porous carbon current collector is 100 MPa to 500 MPa.
  • the resistance is more than 98% of the initial resistance, and the strength is more than 98% of the initial strength.
  • the elongation of the porous carbon current collector is 2% to 10%.
  • At least one surface of the porous carbon current collector is further provided with a metal layer.
  • the metal coating on the surface of the carbon current collector is beneficial to improve its electronic conduction. It can be used in the case of low conductivity of the main material. Considering the influence of thickness and the retention of electrolyte, the coverage should be less than 70% and the thickness should be less than 2 ⁇ m.
  • the ratio of the projected area of the metal layer on the surface of the porous carbon current collector to the area of the porous carbon current collector is 5% to 70% (tested using a KEYENCE VHX5000).
  • the thickness of the metal layer is 0.2 ⁇ m to 2 ⁇ m.
  • the metal in the metal layer includes at least one of copper, aluminum, gold, silver or nickel, and the introduction method may be electroplating, deposition or spraying.
  • the current collector of the present application can be prepared by a conventional melt extraction pore-making method.
  • the melt-extraction pore-forming method includes: casting the carbon material, the polymer, and the pore-forming agent into a conductive composite film by melt extrusion; thermally stretching the conductive composite film; After the conductive composite film is removed.
  • the porosity of the current collector is controlled by changing the content of the pore-forming agent, and the pore distribution is controlled by changing the size of the pore-forming agent.
  • the pore-forming agent used in the present application is not particularly limited, as long as the additive is suitable for forming the pore structure of the polymer in the present application, it can be used in the present application.
  • the pore former is one or more of polyvinyl alcohol and polyethylene glycol.
  • a second aspect of the present application provides an electrochemical device comprising the porous current collector provided by the present application.
  • the porous current collector provided in the present application can be used as the current collector of the positive electrode sheet and the negative electrode sheet.
  • the positive electrode sheet includes the porous current collector provided herein. According to some embodiments, the positive electrode sheet further includes a positive active material disposed on the porous current collector.
  • the positive active material of the present application is not particularly limited, and any positive active material known in the art can be used, for example, it can include nickel cobalt lithium manganate (811, 622, 523, 111), nickel cobalt lithium aluminate, lithium iron phosphate, At least one of lithium-rich manganese-based material, lithium cobaltate, lithium manganate, lithium iron manganese phosphate or lithium titanate.
  • the negative electrode sheet includes the porous current collector provided herein. According to some embodiments, the negative electrode sheet further includes a negative electrode active material disposed on the porous current collector.
  • the negative electrode active material in the present application is not particularly limited, and any negative electrode active material known in the art can be used. For example, at least one of artificial graphite, natural graphite, mesocarbon microspheres, soft carbon, hard carbon, silicon, silicon carbon, lithium titanate, and the like may be included.
  • the electrochemical device of the present application such as a lithium ion battery, further includes an electrolyte, and the electrolyte may be one or more of a gel electrolyte, a solid electrolyte, and an electrolyte, and the electrolyte includes a lithium salt and a non-aqueous solvent.
  • the lithium salt is selected from 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.
  • LiPF 6 may be chosen as the lithium salt because it gives high ionic conductivity and improves cycling characteristics.
  • the non-aqueous solvent may be a carbonate compound, a carboxylate compound, an ether compound, other organic solvents, or a combination thereof.
  • the above-mentioned carbonate compound may be a chain carbonate compound, a cyclic carbonate compound, a fluorocarbonate compound, or a combination thereof.
  • Examples of the above-mentioned chain carbonate compound are dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), carbonic acid Methyl ethyl ester (MEC) and combinations thereof.
  • Examples of cyclic carbonate compounds are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylethylene carbonate (VEC), and combinations thereof.
  • fluorocarbonate compounds are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Ethyl carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-dicarbonate Fluoro-1-methylethylene, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, and combinations thereof.
  • FEC fluoroethylene carbonate
  • 1,2-difluoroethylene carbonate 1,1-difluoroethylene carbonate
  • 1,1,2-trifluoroethylene carbonate Ethyl carbonate 1,1,2,2-tetrafluoroethylene carbonate
  • 1-fluoro-2-methylethylene carbonate 1-fluoro-1-methylethylene carbonate
  • 1,2-dicarbonate Fluoro-1-methylethylene 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethyl
  • carboxylate compounds are methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, ⁇ -butyrolactone , caprolactone, valerolactone, mevalonolactone, caprolactone, and combinations thereof.
  • ether compounds examples include dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethyl ether Oxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, and combinations thereof.
  • Examples of the above-mentioned other organic solvents are dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, Formamide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, and phosphate esters and combinations thereof.
  • the material and shape of the separator used in the electrochemical device of the present application are not particularly limited, and it may be any technique disclosed in the prior art.
  • the separator includes a polymer or inorganic or the like formed from a material that is stable to the electrolyte of the present application.
  • the separator may include a substrate layer and a surface treatment layer.
  • the base material layer is a non-woven fabric, film or composite film with a porous structure, and the material of the base material layer is selected from at least one of polyethylene, polypropylene, polyethylene terephthalate and polyimide.
  • a polypropylene porous membrane, a polyethylene porous membrane, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a polypropylene-polyethylene-polypropylene porous composite membrane can be selected.
  • At least one surface of the base material layer is provided with a surface treatment layer, and the surface treatment layer may be a polymer layer or an inorganic material layer, or a layer formed by mixing a polymer and an inorganic material.
  • the inorganic layer includes inorganic particles and a binder, and the inorganic particles are selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, At least one of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate.
  • the binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinylalkoxy , at least one of polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.
  • the polymer layer contains a polymer, and the material of the polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinylalkoxy, polyvinylidene fluoride, At least one of poly(vinylidene fluoride-hexafluoropropylene).
  • the present application further provides an electronic device comprising the electrochemical device described herein.
  • electronic devices of the present application include, but are not limited to, notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini CD, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, Motorcycle, Power-assisted Bicycle, Bicycle , lighting equipment, toys, game consoles, clocks, power tools, flashes, cameras, large household batteries and lithium-ion capacitors, etc.
  • any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with any other lower limit to form an unspecified range, and likewise any upper limit can be combined with any other upper limit to form an unspecified range.
  • each individually disclosed point or single value may itself serve as a lower or upper limit in combination with any other point or single value or with other lower or upper limits to form a range that is not expressly recited.
  • a list of items to which the terms "at least one of,” “at least one of,” “at least one of,” or other similar terms are linked to can mean any combination of the listed items. For example, if items A and B are listed, the phrase “at least one of A and B” means A only; B only; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C” means A only; or B only; C only; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C.
  • Item A may contain a single component or multiple components.
  • Item B may contain a single component or multiple components.
  • Item C may contain a single component or multiple components.
  • Thickness of current collector Take a current collector with a length of 40cm and a width of 20cm to ensure that the current collector is flat and wrinkle-free. Use a Mitutoyo micrometer to test the thickness of 12 different positions within this size range, and take the average value.
  • Current collector resistance Take a current collector with a length of 40cm and a width of 20cm to ensure that the current collector is flat and wrinkle-free. Use a BER1300 resistance meter and choose the four-point probe method to test the resistance of 12 different positions within this size range and take the average value.
  • Current collector strength and elongation Take a current collector with a length of 40cm and a width of 20cm to ensure that the current collector is flat and wrinkle-free. Cut it into a spline with a width of 12mm and a length of 100mm along the length direction. Use an Instron3365 universal testing machine and select a tensile fixture for testing. , the distance between the clamps, that is, the length of the test section is 50mm, the tensile rate is 10mm/min, and the average value of 12 test strips is taken to calculate the strength and elongation of the sample when it is broken.
  • Current collector pore structure refer to the standard GB/T 21650 mercury porosimetry and gas adsorption method to determine the pore size distribution and porosity of solid materials. Take three current collector samples with a width of 20mm and a length of 300mm, and weigh them; use an Autopore V 9620 mercury porosimeter for testing, roll up the samples along the length direction and put them into a sample tube for sealing. The volume of the sample tube is V0; The sample tube is placed in a low-pressure chamber for low-pressure mercury filling. When the volume of the sample tube other than the sample is filled with mercury, the volume of the filled mercury is V1. Since the mercury is outside the sample at this time, it is not pressed into the sample.
  • the sample volume is (V0-V1), put the sample tube into the high-pressure chamber for high-pressure mercury filling, so that the mercury enters the hole of the sample, and the total volume of mercury charged into the sample is the pore volume V2 of the sample, and obtain
  • the pore size-volume distribution curve of the current collector, and the pore size range of the current collector corresponds to the pore size distribution range in the pore size-volume distribution curve.
  • the calculation method of porosity is V2/(V0-V1), the cumulative mercury injection volume corresponding to the pressure in the pore size range of 0.03 ⁇ m to 0.2 ⁇ m is the volume V3, and the volume of the pores in the pore size range of 0.03 ⁇ m to 0.2 ⁇ m accounts for the total pore volume. Percent V3/V2.
  • the test values are all obtained by taking the average value of 3 samples.
  • Air permeability of current collectors refer to the standard GB/T 458-2008 Determination of air permeability of paper and cardboard. Take 12 pieces of current collectors with a size of 5cm ⁇ 5cm to ensure that the current collectors are flat without wrinkling and damage. Use a Gurley 4110C air permeability tester to test to ensure that the current collector covers all the discs to be tested, test 100cc of gas for the time of the current collector, and take the average value of 12 pieces of current collectors as the air permeability.
  • Coverage of metal coating Take 12 pieces of current collector samples with a size of 10mm ⁇ 10mm, use KEYENCE VHX5000 to test, the magnification is 500 times, the automatic measurement area mode calculates the coverage, and takes the average value of 12 pieces.
  • Thickness of metal coating Take 12 pieces of current collectors, size 10mm ⁇ 10mm, use IB-09010CP to cut the cross-section, use SIGMA/X-max field emission scanning electron microscope to test the thickness of metal coating on the cross-section of 12 pieces of current collector, select each piece 3 positions, take the average of all data.
  • the stretch rate of the polymer film prepare the polymer into a film with a thickness of 10 ⁇ m to 15 ⁇ m, cut it into a spline with a width of 8mm and a length of 40mm to 50mm, and use the DMA850 of TA Instruments to test, the test mode is stretching , place the spline in the tensile jig, adjust the upper and lower distance of the jig to be the length of the sample, the length is between 15mm and 15.5mm, denoted as L1, raise the test furnace to 110°C at a heating rate of 10°C/min, and measure the length of the sample along the Apply 5g force in the stretching direction, record the change of the sample length, after 20min, the sample length is L2, and the tensile ratio of the film is calculated: (L2-L1)/L1.
  • 1.5C charging capacity retention rate at 25°C, the cell with SOC of 0% is charged to 100% SOC with 0.2C constant current, and constant voltage is charged to 0.05C, the charging capacity is C0, and the 0.5C DC discharge is to 0% SOC, 1.5C constant current charging to 100% SOC, charging capacity is C1, C1/C0.
  • 2C discharge capacity retention rate at 25°C, the cell with SOC of 0% is charged to 100% SOC with 0.2C constant current, constant voltage charged to 0.05V, 0.2C DC discharge to 0% SOC, the discharge capacity is D0, 0.2 C constant current charge to 100% SOC, constant voltage charge to 0.05V, 2C DC discharge to 0% SOC, the discharge capacity is D1, D1/D0.
  • -20°C_0.5C capacity retention rate at 25°C, charge the cell with SOC of 0% to 100% SOC with 0.2C constant current, charge to 0.05V with constant voltage, and discharge 0.5C DC to 0% SOC, the discharge capacity It is D0; at 25°C, the cell with SOC of 0% is charged to 100% SOC with 0.2C constant current, charged to 0.05V with constant voltage, and discharged to 0% SOC with 0.5C DC at -20°C, and the discharge capacity is D1 , D1/D0.
  • Carbon materials used in the examples and comparative examples carbon nanotubes: the diameter of the tube is 20-50 nm, the tube length is 0.5-5 ⁇ m, and the specific surface area is 200 m 2 /g.
  • Polyethylene high density polyethylene, the melting point is 142°C, the molecular weight is 200,000, the melt index is 3g/10min (200°C/21.6Kg), the liquid absorption rate is 0.2%, and the film stretch rate is -2.5%.
  • Polypropylene isotactic polypropylene, the melting point is 170°C, the molecular weight is 300,000, the melt index is 1g/10min (200°C/21.6Kg), the liquid absorption rate is 0.2%, and the film stretch rate is -1.5%.
  • Polyimide melting point 194°C, molecular weight 400,000, melt index 0.5g/10min (200°C/21.6Kg), liquid absorption rate 0.3%, film stretch rate 0.8%.
  • Polyoxymethylene melting point is 185°C, molecular weight is 340,000, melt index is 0.7g/10min (200°C/21.6Kg), liquid absorption rate is 1%, and film stretch rate is 1.1%.
  • Ethylene-vinyl acetate copolymer melting point 155°C, molecular weight 370,000, melt index 1.9g/10min (200°C/21.6Kg), liquid absorption 0.3%, film stretch rate -2.4%.
  • Carbon nanotubes, polyethylene and pore-forming agent polyvinyl alcohol (polymerization degree 400-500, alcoholysis degree 88%) are cast into conductive composite films by melt extrusion, wherein the mass ratio of carbon nanotubes and polyethylene is 30 /70.
  • the conductive composite membrane is thermally stretched to a target thickness, and the membrane is placed in a solvent to wash away the pore-forming agent and dry to obtain a porous carbon current collector.
  • the porosity of the porous carbon current collector prepared in this example is 38.2%, the proportion of pores of 0.03-0.2 ⁇ m is 89.5%, and the thickness is 5 ⁇ m.
  • the positive active material lithium cobaltate, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 94:3:3, and then N-methylpyrrolidone (NMP) was added as a solvent to prepare a solid content of 75%. slurry and mix well.
  • the slurry was uniformly coated on the above-mentioned porous carbon current collector, dried at 90°C, and cold-pressed to obtain a positive electrode sheet with a positive active material layer thickness of 100 ⁇ m, and then repeat the above on the other surface of the positive electrode sheet step to obtain a positive electrode sheet coated with a positive electrode active material layer on both sides. Cut the positive pole piece into a size of 74mm ⁇ 867mm and weld the tabs for later use.
  • the negative active materials artificial graphite, acetylene black, styrene-butadiene rubber and sodium carboxymethyl cellulose are mixed in a mass ratio of 96:1:1.5:1.5, and then deionized water is added as a solvent to prepare a slurry with a solid content of 70% , and stir well.
  • the slurry was uniformly coated on the above-mentioned porous carbon current collector, dried at 110°C, and after cold pressing, a negative electrode pole piece with a negative electrode active material layer thickness of 150 ⁇ m was obtained on one side coated with a negative electrode active material layer, and then the negative electrode was placed on the negative electrode.
  • the above coating steps are repeated on the other surface of the pole piece to obtain a negative pole piece coated with a negative electrode active material layer on both sides. Cut the negative pole piece into a size of 74mm ⁇ 867mm and weld the tabs for later use.
  • the non-aqueous organic solvents ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), propyl propionate (PP), vinylene carbonate ( VC) is mixed according to the mass ratio of 20:30:20:28:2, then lithium hexafluorophosphate (LiPF 6 ) is added to the non-aqueous organic solvent to dissolve and mix uniformly to obtain an electrolyte, wherein the mass ratio of LiPF 6 to the non-aqueous organic solvent to 8:92.
  • LiPF 6 lithium hexafluorophosphate
  • the above-prepared positive pole piece, separator, and negative pole piece are stacked in order, the side of the separator with the first coating is in contact with the positive pole piece, and the side of the separator with the second coating is in contact with the negative pole piece , and rolled to obtain an electrode assembly.
  • the electrode assembly is put into an aluminum-plastic film packaging bag, and the moisture is removed at 80 ° C, the prepared electrolyte is injected, and the lithium ion battery is obtained through vacuum packaging, standing, forming, and shaping.
  • Example 2 the difference from Example 1 is that the porosity of the current collector is adjusted, and the parameter changes are shown in Table 2.
  • Example 1 The difference from Example 1 is that the copper foil is used as the negative electrode current collector, the aluminum foil is used as the positive electrode current collector, and other conditions are the same.
  • the porosity of the current collector increases (from 9.7% to 58.7%), and the liquid retention capacity improves, which is beneficial to the improvement of the charge-discharge capacity retention rate and the low-temperature capacity retention rate; however, the increase of the current collector porosity is not enough. It is beneficial to liquid retention, but at the same time, it will deteriorate the mechanical properties and cause its strength to decrease. When the porosity exceeds 60%, it is not conducive to the subsequent processing such as coating and cold pressing.
  • Example 1 the difference from Example 1 is that the pore volume of the current collector is adjusted. See Table 2 for parameter changes.
  • the existence of the current collector pore structure will cause a certain decline in the mechanical properties of the current collector, which can be reduced from the perspective of pore size distribution.
  • the smaller pores with larger pores have a greater impact on the strength, and the proportion should be reduced.
  • the proportion of small pores of 0.03 to 0.2 ⁇ m is preferably not low. at 80%. It can be seen from Table 2 that the uniform pore distribution has no effect on the air permeability and resistance, but it is conducive to the uniform structure of the current collector, which further ensures the improvement of the electrical performance; the uniform distribution of the pores is conducive to the improvement of the mechanical performance of the current collector and avoids poor processing.
  • Example 1 the difference from Example 1 is that the type of polymer is adjusted, and the parameter changes are shown in Table 3.
  • Example 1 the difference from Example 1 is that the polymer content, that is, the polyethylene content, is adjusted, and the parameter changes are shown in Table 4.
  • the increase of the polymer content is beneficial to the improvement of mechanical properties, but since the polymer does not have electrical conductivity, the increase of the content also increases the resistance of the current collector, which is not conducive to electron conduction. Therefore, the polymer content is preferably not more than 60 %.
  • Example 1 the difference from Example 1 is that the thickness of the current collector is adjusted, and the parameter changes are shown in Table 5.
  • the increase in the thickness of the current collector has basically no effect on the mechanical properties, and the electrolyte retention increases to a certain extent, but has little effect on the performance; however, the increase in the thickness of the current collector will lose the volumetric energy density, preferably not more than 30 ⁇ m.
  • Example 1 the difference from Example 1 is that metal coating is applied on the surface of the current collector or the main material of the negative electrode is changed, and the parameter changes are shown in Table 6.
  • Adding a metal coating on the surface of the carbon current collector can increase its electronic conduction.
  • the introduction of a metal coating on the surface of the current collector is beneficial to the performance improvement. Therefore, the metal coating can be introduced when the electrical conductivity of the main material is low.
  • the coverage of the metal coating is preferably ⁇ 70%, and the thickness is ⁇ 2 ⁇ m.

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Abstract

提供一种多孔碳集流体和电化学装置，多孔集流体包括碳材料（1）和聚合物（2），其中，多孔碳集流体的孔隙率为9％至60％；还提供一种电化学装置，电化学装置包括多孔碳集流体，多孔碳集流体可提升电池倍率性能。

Description

一种多孔碳集流体及电化学装置 技术领域
本申请涉及储能领域，具体涉及一种多孔碳集流体及电化学装置。
背景技术
近年来，便携式电子产品如智能手机、笔记本电脑、平板电脑等不断更新换代，曲面显示屏、智能服装、电子皮肤、可植入医疗器械等越来越多的电子设备正在向着轻薄化、柔性化和可穿戴的方向发展。目前为电子产品供电的电化学装置，包括电池和超级电容器等，很难实现灵活弯折，难以满足未来柔性电子技术发展的需求。因此发展柔性电子技术必须要发展与之适应的轻薄且柔性的新型锂离子电池。而发展柔性锂离子电池的主要困难在于如何获得高性能的柔性轻质电极极片。
当前锂离子电池集流体以铜箔和铝箔为主，是除了正负极材料外电池中最重的部分，且金属材料柔韧性差，不适用用柔性电极中。可弯折柔性锂离子电池的柔性基体主要有2种：
(1)非导电性柔性基体，如高分子聚合物、纸张、纺织布。
(2)导电性柔性基体，主要采用石墨烯或碳纳米管等碳材料薄膜作为柔性基体，活性物质附着在其结构单元中形成柔性电极。其在质量方面具有明显优势，是柔性电池高能量密度、轻量化的主流发展方向。
为了满足柔性电子器件待机时间长、充电时间短的特性，要求柔性储能器件具有高的能量密度和功率密度。目前已报道的柔性锂离子电池的电化学性能，特别在高功率性能方面，仍远远达不到常规锂离子电池的水平，也远不能满足实际应用的需求。因此在高功率性能方面的提高是目前柔性锂离子电池研究领域的难点，而与常规锂离子电池相同，较低的锂离子迁移率是限制高功率性能的重要原因。
发明内容
针对现有技术存在的问题，本申请的目的在于制备出一种可提升电池倍率性能的多孔碳集流体以及包含所述多孔碳集流体的电化学装置和电子装置。
在第一方面，本申请提供一种多孔碳集流体，该多孔碳集流体包括碳材料和聚合物， 其中，所述多孔碳集流体的孔隙率为9％至60％。
根据本申请的一些实施方式，所述多孔碳集流体满足以下特征(1)至(3)中的至少一者：(1)所述多孔碳集流体的孔径范围为0.02μm至1μm；(2)所述多孔碳集流体的透气度为100s/100cc至500s/100cc；(3)所述多孔碳集流体中孔径范围在0.03μm至0.2μm的孔的体积占总的孔体积的百分比为80％至100％。
根据本申请的一些实施方式，基于所述多孔碳集流体的总质量，所述碳材料的质量含量为40％至90％，所述聚合物的质量含量为10％至60％。
根据本申请的一些实施方式，所述聚合物满足以下特征(4)至(8)中的至少一者：(4)所述聚合物的熔点范围为130℃至200℃；(5)所述聚合物的重均分子量范围为15万至100万；(6)所述聚合物的熔融指数为0.3g/10min至20g/10min；(7)所述聚合物在电解液中的吸液率小于5％；(8)所述聚合物的胶膜拉伸率为-5％至5％。
根据本申请的一些实施方式，所述多孔碳集流体的厚度为3μm至30μm。
根据本申请的一些实施方式，所述碳材料包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管或碳纤维中的至少一种。
根据本申请的一些实施方式，所述聚合物包括聚乙烯、聚丙烯、聚甲基丙烯酸甲酯、聚酰胺、聚乙烯醇、聚甲醛、聚酰亚胺、乙烯-醋酸乙烯共聚物或聚偏氟乙烯中的至少一种。
根据本申请的一些实施方式，所述多孔碳集流体满足以下特征(9)至(12)中的至少一者：(9)所述多孔碳集流体的电阻为3mΩ至100mΩ；(10)所述多孔碳集流体的强度为100MPa至500MPa；(11)所述多孔碳集流体经120℃烘烤15min后，电阻为初始电阻的98％以上，强度为初始强度的98％以上；(12)所述多孔碳集流体的延伸率为2％至10％。
根据本申请的一些实施方式，所述多孔碳集流体的至少一个表面还设置有金属层。根据本申请的一些实施方式，所述金属层在所述多孔碳集流体表面的投影面积与所述多孔碳集流体面积的比值为5％至70％。根据本申请的一些进一步实施方式，所述金属层的厚度为0.2μm至2μm。根据本申请的一些进一步实施方式，所述金属层中的金属包括铜、铝、金、银或镍中的至少一种。
在第二方面，本申请提供了一种电化学装置，该电化学装置包括如本申请第一方面所述的多孔碳集流体。
在第二方面，本申请提供了一种电子装置，包括如本申请第二方面所述的电化学装置。
本申请提供一种多孔碳集流体，该多孔碳集流体包括碳材料和聚合物，且多孔碳集流体的孔隙率为9％至60％。本申请的多孔碳集流体具有特定多孔结构，使得集流体具备一定的保液能力，克服了现有有柔性锂离子电池的高功率性能较差的缺点，提升锂离子电池的倍率与低温性能。
附图说明
图1是根据本申请的实施方式的集流体的示意图，其中1表示碳材料，2表示聚合物。
图2是根据本申请的实施方式的集流体截面的SEM图。
具体实施方式
下面结合具体实施方式，进一步阐述本申请。应理解，这些具体实施方式仅用于说明本申请。
本申请第一方面提供一种多孔碳集流体，其包括碳材料和聚合物，并且所述多孔碳集流体的孔隙率为9％至60％。孔隙率由聚合物之间的间隙或聚合物与碳材料之间间隙或碳材料与碳材料之间间隙所贡献。集流体孔隙率增加，保液能力提升，有利于充放电容量保持率与低温容量保持率的提升，但是孔隙率过高会恶化集流体力学性能，造成其强度下降，不利于后续涂布冷压等加工过程。
与现有金属箔材集流体相比，碳材料作为集流体可提升电极柔性与能量密度，其制备的极片适用于柔性电子器件用电池。针对现有柔性锂离子电池的高功率性能较差的缺点，本申请的多孔碳集流体具有特定多孔结构，使得集流体具有一定的保液能力，从而提升锂离子电池倍率与低温性能。
在一些实施例中，所述多孔碳集流体的孔隙率为10％、15％、18％、25％、28％、30％、35％、38％、40％、45％、18％、52％、56％或60％。
在一些实施例中，所述多孔碳集流体的孔径范围为0.02μm至1μm。在一些实施例中，所述多孔碳集流体中孔径范围在0.03μm至0.2μm的孔的体积占总的孔体积的百分比为80％至100％，例如80％、85％、90％、95％、98％等。多孔碳集流体孔径满足上述范围，可以减少集流体孔结构的存在对集流体力学性能造成的不利影响，通过减少大孔比例以及提高孔径0.03μm至0.2μm的小孔比例，使得孔分布更加均匀，进而使得集流体结构均匀，进一步保证电性能的提升，同时也有利于集流体力学性能提升，避免加工过程不良。
在一些实施例中，所述多孔碳集流体的透气度为100s/100cc至500s/100cc。
在一些实施例中，所述多孔碳集流体由碳材料与聚合物组成。在一些实施例中，基于所述多孔碳集流体的总质量，所述碳材料的质量含量为40％至90％。由于聚合物不具有导电性，因此含量增加会使集流体电阻增加，不利于电子传导，聚合物含量优选不超过60％。在一些实施例中，基于所述多孔碳集流体的总质量，所述聚合物的质量含量为10％至60％。
在一些实施例中，所述聚合物的熔点在130℃至200℃范围内。在一些实施例中，所述聚合物的熔点在130℃至150℃、150至180℃或180至200℃范围内。聚合物的熔点过低，使得集流体能承受的加工温度范围有限，不利于集流体的尺寸稳定以及锂离子电池的制作加工。聚合物的熔点过高，难以熔融加工制作集流体，且不利于集流体制作过程中加入的造孔剂的稳定性。
在一些实施例中，所述聚合物的重均分子量范围为15万至100万，例如15万、20万、25万、30万、35万、40万、45万等。聚合物的分子量过低，会导致分子链间作用力弱，分子链运动能力增强，从而使得聚合物熔点降低、熔融指数增加、力学性能下降、尺寸稳定性减弱，难以保证集流体本身的制备加工过程稳定与集流体在浆料涂布过程稳定。聚合物分子量过大，一方面合成过程困难，难以找到合适的聚合物使用；另一方面，大分子链所起的强物理交联使得造孔剂进入聚合物网络困难，难以制备出尺寸均匀的孔结构。
在一些实施例中，所述聚合物的熔融指数为0.3g/10min至20g/10min，例如0.3g/10min、1.0g/10min、1.5g/10min、2.0g/10min、3.0g/10min、4.0g/10min、5.0g/10min、6g/10min、10g/10min等。为了保证本申请多孔碳集流体的制备过程可行，要求聚合物具有一定的熔融加工能力。聚合物的熔融指数在一定程度上反应熔融加工能力，熔融指数越高，聚合物高温下流动能力越强，难以制备为尺寸稳定的复合膜，熔融指数越低，熔融物流动能力减弱，难以通过熔融方式加工。
在一些实施例中，所述聚合物在电解液中的吸液率小于5％。根据本申请，聚合物在电解液中的吸液率表示将聚合物的胶膜(胶膜的厚度可以在10μm至15μm范围内)在电解液或电解液溶剂中进行浸渍后的重量变化率，计算式可以为(m2-m1)/m1，其中，m1表示浸渍前的胶膜重量，m2表示浸渍后的胶膜重量。浸渍的时间可以是48h-96h(例如72h)，浸渍温度可以是70℃-90℃(例如85℃)。集流体在使用过程中多孔结构起保液作用，其中的聚合物成分需具有一定的耐电解液能力，避免集流体因吸液膨胀所导致的尺寸变化、导电网络结构变化、力学性能变化，从而使集流体在电芯使用过程中结构保持稳 定。根据一些实施例，测试吸液率时使用的电解液溶剂是EC与DMC，具体质量比可以为1/1。
在一些实施例中，所述聚合物的胶膜拉伸率为-5％至5％。根据本申请，聚合物的胶膜拉伸率表示将聚合物的胶膜沿胶膜长度方向进行拉伸后的胶膜长度变化率，计算式可以为(L2-L1)/L1，其中L1表示拉伸前的胶膜长度，L2表示拉伸后的胶膜长度。由于使用本申请集流体进行正负极浆料涂布时，涂布烘干温度一般在90℃至110℃以内，因此集流体需在110℃内具有较好的尺寸稳定性，避免在涂布过程因集流体热收缩或膨胀导致的加工异常。在一些实施例中，聚合物的胶膜拉伸率为-5％至0％。在另外一些实施例中，聚合物的胶膜拉伸率为0％至-5％。因此，要求所述聚合物的胶膜拉伸率为-5％至5％。在一些实施例中，所述聚合物的胶膜拉伸率的测试条件包括：温度在90℃至110℃范围内，胶膜的厚度在10μm至15μm范围内，以5g-10g力进行拉伸，拉伸时间为10min至30min。在一些实施例中，所述聚合物的胶膜拉伸率的测试条件包括：温度110℃，胶膜的厚度10μm至15μm，以5g力进行拉伸，拉伸时间为20min。
在一些实施例中，所述聚合物包括聚乙烯、聚丙烯、聚甲基丙烯酸甲酯、聚酰胺、聚乙烯醇、聚甲醛、聚酰亚胺、乙烯-醋酸乙烯共聚物、聚偏氟乙烯的至少一种。
在一些实施例中，所述多孔碳集流体的厚度为3μm至30μm。集流体厚度增加，力学性能无影响，电解液保有量有一定增加，但对性能影响较小；考虑到集流体厚度增加会损失体积能量密度，因此优选不超过30μm。在一些实施例中，所述多孔碳集流体的厚度为3μm、8μm、10μm、15μm、20μm、25μm或30μm等。
在一些实施例中，所述碳材料包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管或碳纤维中的至少一种。碳材料起导电作用，种类没有特殊要求，考虑到分散性与导电性，优选所述碳材料的D50在30nm至500nm，比表面积在5m 2/g至300m 2/g。在一些实施例中，碳材料为碳纳米管，优选地，管径为20nm至50nm，管长为0.5μm至5μm。在一些实施例中，所述碳材料的比表面积为100m 2/g至300m 2/g。
在一些实施例中，所述多孔碳集流体的电阻为3mΩ至100mΩ。在一些实施例中，所述多孔碳集流体的强度为100MPa至500MPa。在一些实施例中，所述多孔碳集流体经120℃烘烤15min后，电阻为初始电阻的98％以上，强度为初始强度的98％以上。在一些实施例中，所述多孔碳集流体的延伸率为2％至10％。
在一些实施例中，所述多孔碳集流体的至少一个表面还设置有金属层。碳集流体表面加金属涂层有利于提升其电子传导，可在主材电导率低的情况下使用，考虑到厚度影响以 及电解液保有，选择覆盖度<70％，厚度<2μm。在一些实施例中，所述金属层在所述多孔碳集流体表面的投影面积与所述多孔碳集流体面积的比值为5％至70％(可使用KEYENCE VHX5000进行测试)。在一些实施例中，所述金属层的厚度为0.2μm至2μm。在一些实施例中，所述金属层中的金属包括铜、铝、金、银或镍中的至少一种，引入方式可以是电镀、沉积或喷涂。
本申请的集流体可通过常规的熔融萃取制孔法制备。在一些实施例中，熔融萃取制孔法包括：将碳材料、聚合物和造孔剂通过熔融挤出流延成为导电复合膜；对导电复合膜进行热拉伸；将造孔剂从拉伸后的导电复合膜中脱除。此方法通过改变造孔剂含量控制集流体孔隙率，通过改变造孔剂尺寸控制孔分布。本申请中使用的造孔剂没有特别限定，只要适用于使本申请中的聚合物形成孔结构的添加剂均可用于本申请。在一些实施例中，所述造孔剂是聚乙烯醇、聚乙二醇中的一种或多种。
本申请第二方面提供了一种电化学装置，所述电化学装置包括本申请提供的多孔集流体。本申请提供的多孔集流体可以作为正极极片与负极极片的集流体。
根据一些实施例，所述正极极片包括本申请提供的多孔集流体。根据一些实施例，所述正极极片还包括设置在所述多孔集流体上的正极活性物质。本申请的正极活性物质没有特别限制，可以使用本领域公知的任何正极活性物质，例如，可以包括镍钴锰酸锂(811、622、523、111)、镍钴铝酸锂、磷酸铁锂、富锂锰基材料、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂中的至少一种。
根据一些实施例，所述负极极片包括本申请提供的多孔集流体。根据一些实施例，所述负极极片还包括设置在所述多孔集流体上的负极活性物质。本申请中的负极活性物质没有特别限制，可以使用本领域公知的任何负极活性物质。例如，可以包括人造石墨、天然石墨、中间相碳微球、软碳、硬碳、硅、硅碳、钛酸锂等中的至少一种。
本申请的电化学装置，例如锂离子电池，还包括电解质，电解质可以是凝胶电解质、固态电解质和电解液中的一种或多种，电解液包括锂盐和非水溶剂。
在本申请一些实施方案中，锂盐选自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、LiSiF 6、LiBOB和二氟硼酸锂中的一种或多种。举例来说，锂盐可以选用LiPF 6，因为它可以给出高的离子导电率并改善循环特性。
非水溶剂可为碳酸酯化合物、羧酸酯化合物、醚化合物、其它有机溶剂或它们的组合。
上述碳酸酯化合物可为链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物或 其组合。
上述链状碳酸酯化合物的实例为碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)及其组合。环状碳酸酯化合物的实例为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)及其组合。氟代碳酸酯化合物的实例为碳酸氟代亚乙酯(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及其组合。
上述羧酸酯化合物的实例为甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、γ-丁内酯、癸内酯、戊内酯、甲瓦龙酸内酯、己内酯及其组合。
上述醚化合物的实例为二丁醚、四甘醇二甲醚、二甘醇二甲醚、1,2-二甲氧基乙烷、1,2-二乙氧基乙烷、乙氧基甲氧基乙烷、2-甲基四氢呋喃、四氢呋喃及其组合。
上述其它有机溶剂的实例为二甲亚砜、1,2-二氧戊环、环丁砜、甲基环丁砜、1,3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、甲酰胺、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯、磷酸三辛酯、和磷酸酯及其组合。
本申请的电化学装置中使用的隔膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施例中，隔膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。
例如隔膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。具体的，可选用聚丙烯多孔膜、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。
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。
无机物层包括无机颗粒和粘结剂，无机颗粒选自氧化铝、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。粘结剂选自聚偏氟乙烯、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、聚乙烯烷氧、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的至少一 种。
聚合物层中包含聚合物，聚合物的材料选自聚酰胺、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、聚乙烯烷氧、聚偏氟乙烯、聚(偏氟乙烯-六氟丙烯)中的至少一种。
本申请进一步提供了一种电子装置，其包括本申请所述的电化学装置。
本申请的电子设备或装置没有特别限定。在一些实施例中，本申请的电子设备包括但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。
为了简明，本文仅具体地公开了一些数值范围。然而，任意下限可以与任何上限组合形成未明确记载的范围；以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，每个单独公开的点或单个数值自身可以作为下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。
在本文的描述中，除非另有说明，“以上”、“以下”包含本数。
除非另有说明，本申请中使用的术语具有本领域技术人员通常所理解的公知含义。除非另有说明，本申请中提到的各参数的数值可以用本领域常用的各种测量方法进行测量(例如，可以按照在本申请的实施例中给出的方法进行测试)。
术语“中的至少一者”、“中的至少一个”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个组分或多个组分。项目B可包含单个组分或多个组分。项目C可包含单个组分或多个组分。
下面结合实施例，进一步阐述本申请。应理解，这些实施例仅用于说明本申请而不用于限制本申请的范围。
一、测试方法
集流体厚度：取40cm长、20cm宽的集流体，保证集流体平整无打皱，使用Mitutoyo万分尺测试此尺寸范围内的12个不同位置厚度，取平均值。
集流体电阻：取40cm长、20cm宽的集流体，保证集流体平整无打皱，使用BER1300电阻仪，选择四探针法，测试此尺寸范围内的12个不同位置电阻，取平均值。
集流体强度和延伸率：取40cm长、20cm宽的集流体，保证集流体平整无打皱，沿长度方向裁为宽12mm、长100mm样条，使用Instron3365万能试验机，选择拉伸夹具进行测试，夹具间距即测试段长度为50mm，拉伸速率10mm/min，测试12根样条取平均值，计算样品拉断时的强度与延伸率。
集流体孔结构：参考标准GB/T 21650压汞法和气体吸附法测定固体材料孔径分布和孔隙度。取3条20mm宽、300mm长的集流体样品，称重；使用Autopore V 9620压汞仪进行测试，将样品沿长度方向卷起并放入样品管进行密封，样品管体积为V0；设备开机，样品管置于低压仓进行低压充汞，当样品管中除样品外的体积被汞充满后，此时充入的汞体积为V1，由于汞此时在样品外部，并未被压入样品的孔中，因此样品体积为(V0-V1)，将样品管放入高压仓中进行高压充汞，使汞进入样品的孔中，充入样品的汞总体积为样品的孔体积V2，并得到集流体的孔径-体积分布曲线，集流体的孔径范围对应孔径-体积分布曲线中的孔径分布范围。孔隙率计算方式为V2/(V0-V1)，孔径范围在0.03μm至0.2μm对应压力的累积进汞体积为体积V3，孔径范围在0.03μm至0.2μm的孔的体积占总的孔体积的百分比V3/V2。测试值均为取3条样品平均值得到。
集流体透气度：参考标准GB/T 458-2008纸和纸板透气度的测定。取12片尺寸为5cm╳5cm集流体，保证集流体平整无打皱无破损。使用Gurley 4110C透气度测试仪进行测试，保证集流体将测试的圆盘全部覆盖，测试100cc气体经过集流体时间，取12片集流体测试平均值为透气度。
金属涂层覆盖度：取12片集流体样品，尺寸10mm╳10mm，使用KEYENCE VHX5000进行测试，放大倍数为500倍，自动测量面积模式计算覆盖度，取12片平均值。
金属涂层厚度：取12片集流体样品，尺寸10mm╳10mm，使用IB-09010CP切割得到截面，使用SIGMA/X-max场发射扫描电镜测试12片集流体的截面金属涂层厚度，每片选取3个位置，取所有数据的平均值。
聚合物吸液率：将聚合物制备为胶膜，厚度在1mm至1.5mm，取3g至3.2g上述胶膜，重量记为m1，浸泡于电解液溶剂(EC/DMC＝1/1)中，电解液溶剂需浸没胶膜，密封放置于85℃烘箱中72h，取出胶膜并擦去表面电解液溶剂，称重记为m2，吸液率计算： (m2-m1)/m1。
聚合物的胶膜拉伸率：将聚合物制备为胶膜，厚度在10μm至15μm，裁剪为宽8mm、长40mm至50mm之间样条，使用TA仪器的DMA850进行测试，测试模式为拉伸，将样条放置于拉伸夹具中，调整夹具上下距离为样品长度，长度在15mm至15.5mm之间，记为L1，将测试炉以10℃/min升温速率升至110℃，对样品沿拉伸方向施加5g力，记录样品长度变化，20min后样品长度为L2，胶膜拉伸率计算：(L2-L1)/L1。
1.5C充电容量保持率：25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05C，充电容量为C0，0.5C直流放电至0％SOC，1.5C恒流充电至100％SOC、充电容量为C1，C1/C0。
2C放电容量保持率：25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05V，0.2C直流放电至0％SOC，放电容量为D0，0.2C恒流充电至100％SOC、恒压充电至0.05V，2C直流放电至0％SOC，放电容量为D1，D1/D0。
-20℃_0.5C容量保持率：25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05V，0.5C直流放电至0％SOC，放电容量为D0；25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05V，-20℃下以0.5C直流放电至0％SOC，放电容量为D1，D1/D0。
二、原料
实施例和对比例中使用的碳材料：碳纳米管：管径20～50nm，管长0.5～5μm，比表面积200m 2/g。
实施例和对比例中使用的聚合物：
1)聚乙烯：高密度聚乙烯，熔点为142℃，分子量20万，熔融指数3g/10min(200℃/21.6Kg)，吸液率0.2％，胶膜拉伸率-2.5％。
2)聚丙烯：等规聚丙烯，熔点170℃，分子量30万，熔融指数1g/10min(200℃/21.6Kg)，吸液率0.2％，胶膜拉伸率-1.5％。
3)聚酰亚胺：熔点194℃，分子量40万，熔融指数0.5g/10min(200℃/21.6Kg)，吸液率0.3％，胶膜拉伸率0.8％。
4)聚甲醛：熔点185℃，分子量34万，熔融指数0.7g/10min(200℃/21.6Kg)，吸液率1％，胶膜拉伸率1.1％。
5)乙烯-醋酸乙烯共聚物：熔点155℃，分子量37万，熔融指数1.9g/10min(200℃ /21.6Kg)，吸液率0.3％，胶膜拉伸率-2.4％。
三、实施例
实施例1
1、多孔集流体的制备：
碳纳米管、聚乙烯和造孔剂聚乙烯醇(聚合度400-500，醇解度88％)通过熔融挤出流延成为导电复合膜，其中，碳纳米管、聚乙烯的质量比为30/70。对导电复合膜进行热拉伸至目标厚度，将膜置于溶剂中洗去造孔剂烘干得到多孔碳集流体。本实施例制备的多孔碳集流体的孔隙率38.2％，0.03～0.2μm孔占比89.5％，厚度为5μm。
2、正极极片的制备：
将正极活性材料钴酸锂、乙炔黑、聚偏二氟乙烯(PVDF)按质量比94：3：3混合，然后加入N-甲基吡咯烷酮(NMP)作为溶剂，调配成固含量为75％的浆料，并搅拌均匀。将浆料均匀涂布在上述多孔碳集流体上，90℃条件下烘干，冷压后得到正极活性材料层厚度为100μm的正极极片，然后在该正极极片的另一个表面上重复以上步骤，得到双面涂布有正极活性材料层的正极极片。将正极极片裁切成74mm×867mm的规格并焊接极耳后待用。
3、负极极片的制备
将负极活性材料人造石墨、乙炔黑、丁苯橡胶及羧甲基纤维素钠按质量比96：1：1.5：1.5混合，然后加入去离子水作为溶剂，调配成固含量为70％的浆料，并搅拌均匀。将浆料均匀涂布在上述多孔碳集流体上，110℃条件下烘干，冷压后得到负极活性材料层厚度为150μm的单面涂布负极活性材料层的负极极片，然后在该负极极片的另一个表面上重复以上涂布步骤，得到双面涂布有负极活性材料层的负极极片。将负极极片裁切成74mm×867mm的规格并焊接极耳后待用。
4、电解液的制备
在含水量小于10ppm的环境下，将非水有机溶剂碳酸乙烯酯(EC)、碳酸二乙酯(DEC)、碳酸亚丙酯(PC)、丙酸丙酯(PP)、碳酸亚乙烯酯(VC)按照质量比20：30：20：28：2混合，然后向非水有机溶剂中加入六氟磷酸锂(LiPF 6)溶解并混合均匀，得到电解液，其中，LiPF 6与非水有机溶剂的质量比为8：92。
5、锂离子电池的制备
将上述制备的正极极片、隔离膜、负极极片按顺序叠好，将隔离膜具有第一涂层的一 面与正极极片接触，将隔离膜具有第二涂层的一面与负极极片接触，并卷绕得到电极组件。将电极组件装入铝塑膜包装袋中，并在80℃下脱去水分，注入配好的电解液，经过真空封装、静置、化成、整形等工序得到锂离子电池。
实施例2-6以及对比例1-2
参照实施例1，与在实施例1的不同之处在于，调整集流体的孔隙率，参数变化参见表2。
对比例3
与实施例1的不同之处在于铜箔作为负极集流体，铝箔作为正极集流体，其他条件相同。
表1集流体孔隙率变化的影响
Figure PCTCN2021083314-appb-000001
由表1可以看出，集流体孔隙率增加(从9.7％增加至58.7％)，保液能力提升，有 利于充放电容量保持率与低温容量保持率的提升；然而，集流体孔隙率提升虽有利于保液，但同时会恶化力学性能，造成其强度下降，当孔隙率超过60％时，不利于后续涂布冷压等加工过程。
实施例7至实施例9
参照实施例1，与实施例1的不同之处在于调整了集流体孔体积，参数变化参见表2。
表2集流体孔体积变化的影响
Figure PCTCN2021083314-appb-000002
集流体孔结构存在会对集流体力学性能造成一定下降，可从孔径分布角度减少影响，大孔较小孔对强度影响更大，应减少其比例，0.03～0.2μm的小孔比例优选不低于80％。由表2可以看出，孔分布均匀对透气度、电阻基本无影响，但有利于集流体结构均匀，进一步保证电性能的提升；孔分布均匀有利于集流体力学性能提升，避免加工过程不良。
实施例10至实施例13
参照实施例1，与实施例1的不同之处在于调整了聚合物种类，参数变化参见表3。
表3聚合物种类变化的影响
Figure PCTCN2021083314-appb-000003
实施例14-18
参照实施例1，与实施例1的不同之处在于调整了聚合物含量即聚乙烯含量，参数变化见表4。
表4聚合物质量含量(％)的影响
Figure PCTCN2021083314-appb-000004
由表4可以看出，聚合物含量增加有利于力学性能提升，但是由于聚合物不具有导电性，因此含量增加也使集流体电阻增加，不利于电子传导，因此，聚合物含量优选不超过60％。
实施例19-20
参照实施例1，与实施例1的不同之处在于调整了集流体的厚度，参数变化见表5。
表5集流体厚度的影响
Figure PCTCN2021083314-appb-000005
由表5可以看出，集流体的厚度增加，对力学性能基本无影响，电解液保有量有一定增加，但对性能影响较小；然而，集流体厚度增加会损失体积能量密度，优选不超过30μm。
实施例21至实施例23
参照实施例1，与实施例1的不同之处在于在集流体表面涂覆金属涂层或者改变负极 主材，参数变化见表6。
表6表面金属涂层和负极主材的影响
Figure PCTCN2021083314-appb-000006
碳集流体表面加金属涂层可增加其电子传导，对于主材为硅材料的负极，由于硅材料电子传导差，在集流体表面引入金属涂层有利于性能提升。因此，可以在主材电导率低的情况下引入金属涂层，考虑到厚度影响以及电解液保有，优选金属涂层覆盖度<70％，厚度<2μm。
以上各实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述各实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请技术方案的范围。

Claims (14)

  1. 一种多孔碳集流体，包括碳材料和聚合物，其中，所述多孔碳集流体的孔隙率为9％至60％。
  2. 根据权利要求1所述的多孔碳集流体，其中，所述多孔碳集流体满足以下特征中的至少一者：
    所述多孔碳集流体的孔径范围为0.02μm至1μm；
    所述多孔碳集流体的透气度为100s/100cc至500s/100cc；
    所述多孔碳集流体中孔径范围在0.03μm至0.2μm的孔的体积占总的孔体积的百分比为80％至100％。
  3. 根据权利要求1所述的多孔碳集流体，其中，基于所述多孔碳集流体的总质量，所述碳材料的质量含量为40％至90％，所述聚合物的质量含量为10％至60％。
  4. 根据权利要求1所述的多孔碳集流体，其中，所述聚合物满足以下特征中的至少一者：
    所述聚合物的熔点范围为130℃至200℃；
    所述聚合物的重均分子量范围为15万至100万；
    所述聚合物的熔融指数为0.3g/10min至20g/10min；
    所述聚合物在电解液中的吸液率小于5％；
    所述聚合物的胶膜拉伸率为-5％至5％。
  5. 根据权利要求1所述的多孔碳集流体，其中，所述多孔碳集流体的厚度为3μm至30μm。
  6. 根据权利要求1所述的多孔碳集流体，其中，所述碳材料包括导电炭黑、乙炔黑、石墨、石墨烯、碳纳米管或碳纤维中的至少一种。
  7. 根据权利要求1所述的多孔碳集流体，其中，所述聚合物包括聚乙烯、聚丙烯、聚甲基丙烯酸甲酯、聚酰胺、聚乙烯醇、聚甲醛、聚酰亚胺、乙烯-醋酸乙烯共聚物、聚偏氟乙烯中的至少一种。
  8. 根据权利要求1所述的多孔碳集流体，其中，所述多孔碳集流体满足以下特征中的至少一者：
    所述多孔碳集流体的电阻为3mΩ至100mΩ；
    所述多孔碳集流体的强度为100MPa至500MPa；
    所述多孔碳集流体经120℃烘烤15min后，电阻为初始电阻的98％以上，强度为初始 强度的98％以上；
    所述多孔碳集流体的延伸率为2％至10％。
  9. 根据权利要求1所述的多孔碳集流体，其中，所述多孔碳集流体的至少一个表面还设置有金属层。
  10. 根据权利要求9所述的多孔碳集流体，其中，所述金属层在所述多孔碳集流体表面的投影面积与所述多孔碳集流体面积的比值为5％至70％。
  11. 根据权利要求9所述的多孔碳集流体，其中，所述金属层的厚度为0.2μm至2μm。
  12. 根据权利要求9所述的多孔碳集流体，其中，所述金属层中的金属包括铜、铝、金、银或镍中的至少一种。
  13. 一种电化学装置，包括如权利要求1至12任一项所述的多孔碳集流体。
  14. 一种电子装置，包括如权利要求13所述的电化学装置。
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