WO2024108520A1 - 二次电池和用电装置 - Google Patents

二次电池和用电装置 Download PDF

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WO2024108520A1
WO2024108520A1 PCT/CN2022/134218 CN2022134218W WO2024108520A1 WO 2024108520 A1 WO2024108520 A1 WO 2024108520A1 CN 2022134218 W CN2022134218 W CN 2022134218W WO 2024108520 A1 WO2024108520 A1 WO 2024108520A1
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Prior art keywords
negative electrode
secondary battery
copolymers
optionally
homopolymers
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PCT/CN2022/134218
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English (en)
French (fr)
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柴志生
金海族
刘超
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宁德时代新能源科技股份有限公司
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Priority to PCT/CN2022/134218 priority Critical patent/WO2024108520A1/zh
Publication of WO2024108520A1 publication Critical patent/WO2024108520A1/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
    • 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 has been made in view of the above-mentioned problems, and an object of the present application is to provide a secondary battery having good cycle performance.
  • the first aspect of the present application provides a secondary battery, which comprises a negative electrode plate and a separator, wherein the negative electrode plate comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector;
  • the capacity per unit area of the negative electrode film layer is recorded as C, and the pore volume per unit area of the separator is recorded as V. Then the secondary battery satisfies: 0.05 cm 3 /Ah ⁇ V/C ⁇ 0.3 cm 3 /Ah, wherein the unit of C is mAh, and the unit of V is cm 3 .
  • the secondary battery of the present application ensures that the ratio of the pore volume of the separator to the capacity per unit area of the negative electrode film layer meets the above range, thereby ensuring the wettability of the separator and the capacity of the negative electrode, so that the corresponding battery has good cycle performance.
  • C is 2-8 mAh, optionally 2.3-5.5 mAh, and further optionally 2.3-5.0 mAh.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • V is 2 ⁇ 10 -4 -20 ⁇ 10 -4 cm 3 , optionally 2 ⁇ 10 -4 -15 ⁇ 10 -4 cm 3 , further optionally 4 ⁇ 10 -4 -10 ⁇ 10 -4 cm 3 .
  • the surface density of the negative electrode film layer is 0.002g/ cm2-0.02g / cm2 , optionally 0.006-0.015g/ cm2 , further optionally 0.005-0.007g/ cm2 .
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the thickness of the negative electrode film layer is 0.03-0.24 mm, and can be 0.08-0.16 mm, thereby further ensuring the wettability of the separator and the capacity of the negative electrode, so that the corresponding battery has good cycle performance.
  • the separator includes a base film and a coating disposed on at least one side of the base film, wherein the coating includes first polymer particles and second polymer particles.
  • the number average particle size of the first polymer particles is greater than the number average particle size of the second polymer particles.
  • the number average particle size of the first polymer particles is 2-8 ⁇ m, optionally 3-7 ⁇ m; and/or the number average particle size of the second polymer particles is 50-800 nm, optionally 100-600 nm.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the content of the first polymer particles is less than or equal to 15% based on the weight of the coating; and/or the content of the second polymer particles is less than or equal to 30% based on the weight of the coating.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the first polymer particles include homopolymers or copolymers of fluorinated olefin monomer units, homopolymers or copolymers of olefin monomer units, homopolymers or copolymers of unsaturated nitrile monomer units, homopolymers or copolymers of oxirane monomer units, homopolymers or copolymers of acrylate monomer units, homopolymers or copolymers of imide monomer units, and at least one of the modified compounds of the above homopolymers or copolymers; and/or, the second polymer particles include homopolymers or copolymers of unsaturated nitrile monomer units, homopolymers or copolymers of fluorinated olefin monomer units, homopolymers or copolymers of styrene monomer units, and at least one of the modified compounds of the above homopolymers or copolymers.
  • the coating further comprises inorganic particles; optionally, the average volume particle size of the inorganic particles is 0.1-2 ⁇ m.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the thickness of the base film is 5-16 ⁇ m; and/or the thickness of the coating is 1-5 ⁇ m.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the ratio of the coating thickness on one side to the base film thickness is 0.1-1.5.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the air permeability of the separator is less than or equal to 370s, and can be 100-250s.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the porosity of the separator is 20%-60%.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the second aspect of the present application further provides an electrical device, characterized in that it comprises the secondary battery described in the first aspect of the present application.
  • the secondary battery of the present application ensures that the ratio of the pore volume of the isolation membrane to the capacity per unit area of the negative electrode film layer meets the above range, thereby ensuring that the isolation membrane has a sufficiently large pore volume while the negative electrode film layer has a sufficient capacity per unit area, so that the corresponding battery has good cycle performance.
  • FIG. 1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 2 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 1 .
  • FIG. 3 is a schematic diagram of an electric device using a secondary battery as a power source according to an embodiment of the present application.
  • Secondary battery 51. Casing; 52. Electrode assembly; 53. Cover plate; 6. Electrical device.
  • range disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range.
  • the range defined in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60-120 and 80-110 is listed for a specific parameter, it is understood that the range of 60-110 and 80-120 is also expected.
  • the numerical range "a-b" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers.
  • the numerical range "0-5" represents that all real numbers between "0-5" have been fully listed herein, and "0-5" is just the abbreviation of these numerical combinations.
  • a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • the method may further include step (c), which means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.
  • the “include” and “comprising” mentioned in this application represent open-ended or closed-ended expressions.
  • the “include” and “comprising” may represent that other components not listed may also be included or only the listed components may be included or only the listed components may be included.
  • the term "or” is inclusive.
  • the phrase “A or B” means “A, B, or both A and B”. More specifically, any of the following conditions satisfies the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or A and B are both true (or exist).
  • the improvement of the isolation membrane is usually to coat a ceramic coating and/or an adhesive coating on the base membrane.
  • This isolation membrane will block the ion channel between the isolation membrane and the pole piece due to the flattening of the adhesive coating after the internal pressure of the battery increases, and the electrolyte infiltration is insufficient, and even black spots, lithium precipitation and other problems may occur.
  • the improvement of the isolation membrane does not take into account the coordination with the positive and negative electrodes. Therefore, the existing improvements to secondary batteries, especially the improvements to the isolation membrane, need to be further improved.
  • the inventors found that when the pore volume of the isolation membrane in the secondary battery and the capacity per unit area of the negative electrode film layer form a specific relationship, both the wetting ability of the isolation membrane and the capacity of the negative electrode are guaranteed, so that the corresponding secondary battery has good cycle performance.
  • the first aspect of the present application provides a secondary battery comprising a negative electrode plate and a separator, wherein the negative electrode plate comprises a negative electrode current collector and a negative electrode film layer disposed on at least one side of the negative electrode current collector;
  • the capacity per unit area of the negative electrode film layer is recorded as C, and the pore volume per unit area of the separator is recorded as V. Then the secondary battery satisfies: 0.05 cm 3 /Ah ⁇ V/C ⁇ 0.3 cm 3 /Ah, wherein the unit of C is mAh, and the unit of V is cm 3 .
  • the secondary battery of the present application ensures that the ratio of the pore volume of the separator to the capacity per unit area of the negative electrode film layer meets the above range, thereby ensuring the wettability of the separator and the capacity of the negative electrode, so that the corresponding battery has good cycle performance.
  • C is the capacity per unit area of the negative electrode film layer, that is, the capacity per cm 2 of the negative electrode film layer (also referred to as per cm 2 of the negative electrode sheet).
  • V is the pore volume per unit area of the separator, that is, the pore volume per cm 2 of the separator.
  • V/C may be any value among 0.05 cm 3 /Ah, 0.07 cm 3 /Ah, 0.08 cm 3 /Ah, 0.09 cm 3 /Ah, 0.1 cm 3 /Ah, 0.15 cm 3 /Ah, 0.18 cm 3 /Ah, 0.20 cm 3 /Ah, 0.24 cm 3 /Ah, 0.25 cm 3 /Ah, 0.28 cm 3 /Ah, 0.3 cm 3 /Ah, or within the range of any two of the above values. Those skilled in the art may adjust and select as needed.
  • C is 2-8 mAh, optionally 2.3-5.5 mAh, further optionally 2.3-5.0 mAh; V is 2-20 ⁇ 10 -4 cm 3 , optionally 2-15 ⁇ 10 -4 cm 3 , further optionally 4-10 ⁇ 10 -4 cm 3 .
  • the pore volume per unit area of the isolation membrane is the pore volume of the isolation membrane under the autogenous pressure inside the battery; typically, the autogenous pressure inside the battery is 0-10 MPa.
  • 0.07 cm 3 /Ah ⁇ V/C ⁇ 0.25 cm 3 /Ah, C is 2-8 mAh, and V is 2 ⁇ 10 - 4 -20 ⁇ 10 -4 cm 3 .
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • 0.08 cm 3 /Ah ⁇ V/C ⁇ 0.2 cm 3 /Ah, C is 2-8 mAh, and V is 2.5 ⁇ 10 -4 -15 ⁇ 10 -4 cm 3 .
  • 0.08 cm 3 /Ah ⁇ V/C ⁇ 0.3 cm 3 /Ah, C is 2-8 mAh, and V is 2-20 ⁇ 10 -4 cm 3 .
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • 0.07 cm 3 /Ah ⁇ V/C ⁇ 0.25 cm 3 /Ah, C is 2-8 mAh, and V is 0.2 ⁇ 10 -3 -1.2 ⁇ 10 -3 cm 3 .
  • 0.05 cm 3 /Ah ⁇ V/C ⁇ 0.2 cm 3 /Ah, C is 2-8 mAh, and V is 0.16 ⁇ 10 -3 -1.0 ⁇ 10 -3 cm 3.
  • 0.15 cm 3 /Ah ⁇ V/C ⁇ 0.25 cm 3 /Ah, C is 2.4-2.9 mAh, and V is 0.4 ⁇ 10 -3 -0.6 ⁇ 10 -3 cm 3 .
  • the surface density of the negative electrode film layer is 0.002-0.02 g/cm 2 , optionally 0.006-0.015 g/cm 2 , further optionally 0.005-0.007 g/cm 2 .
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the negative electrode film layer contains 80-99%, and optionally 93-97%, of the negative electrode active material, based on the weight of the negative electrode film layer, thereby further ensuring the wettability of the separator and the capacity of the negative electrode, so that the corresponding battery has good cycle performance.
  • the thickness of the negative electrode film layer is 0.03-0.24 mm, and can be 0.08-0.16 mm, thereby further ensuring the wettability of the separator and the capacity of the negative electrode, so that the corresponding battery has good cycle performance.
  • the separator includes a base film and a coating disposed on at least one side of the base film, wherein the coating includes first polymer particles and second polymer particles.
  • the number average particle size of the first polymer particles is greater than the number average particle size of the second polymer particles.
  • the number average particle size of the first polymer particles is 2-8 ⁇ m, optionally 3-7 ⁇ m; and/or the number average particle size of the second polymer particles is 50-800 nm, optionally 100-600 nm.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the content of the first polymer particles is less than or equal to 15%, based on the weight of the coating; and/or the content of the second polymer particles is less than or equal to 30%, based on the weight of the coating.
  • the first polymer particles include homopolymers or copolymers of fluorinated olefin monomer units, homopolymers or copolymers of olefin monomer units, homopolymers or copolymers of unsaturated nitrile monomer units, homopolymers or copolymers of oxirane monomer units, homopolymers or copolymers of acrylate monomer units, homopolymers or copolymers of imide monomer units, and at least one of the modified compounds of the above homopolymers or copolymers; and/or, the second polymer particles include homopolymers or copolymers of unsaturated nitrile monomer units, homopolymers or copolymers of fluorinated olefin monomer units, homopolymers or copolymers of styrene monomer units, and at least one of the modified compounds of the above homopolymers or copolymers.
  • the first polymer particles may include homopolymers or copolymers of fluorine-containing olefinic monomer units, homopolymers or copolymers of olefinic monomer units, homopolymers or copolymers of unsaturated nitrile monomer units, homopolymers or copolymers of alkylene oxide monomer units, homopolymers or copolymers of acrylate monomer units, homopolymers or copolymers of imide monomer units, and one or more of the modified compounds of the above homopolymers or copolymers.
  • the fluorine-containing olefinic monomer unit may be selected from one or more of difluoroethylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, and hexafluoropropylene.
  • the olefin-based monomer unit may be selected from one or more of ethylene, propylene, butadiene, isoprene, and the like.
  • the unsaturated nitrile monomer unit can be selected from one or more of acrylonitrile, methacrylonitrile, and the like.
  • the alkylene oxide monomer unit can be selected from one or more of ethylene oxide, propylene oxide, and the like.
  • the acrylic acid ester monomer unit can be selected from one or more of methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, isooctyl methacrylate, and the like.
  • the first polymer particles may include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polyethylene, polypropylene, polyacrylonitrile, polyethylene oxide, polyacrylate, polymethacrylate, copolymers of different fluorine-containing olefinic monomer units, copolymers of fluorine-containing olefinic monomer units and olefinic monomer units, copolymers of fluorine-containing olefinic monomer units and acrylic monomer units, copolymers of fluorine-containing olefinic monomer units and acrylic ester monomer units, polyvinyl pyrrolidone, polyimide, polyethylene oxide (PEO), and one or more of modified compounds of the above homopolymers or copolymers.
  • the first polymer particles may include polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer (PADF-HFP), vinylidene fluoride-trifluoroethylene-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-acrylic acid copolymer, vinylidene fluoride-hexafluoropropylene-acrylate copolymer, polyvinyl pyrrolidone, polyimide, polyethylene oxide (PEO), styrene-vinyl acetate-pyrrolidone copolymer, and one or more of modified compounds of the above copolymers.
  • PAN polyacrylonitrile
  • PMMA polymethyl methacrylate
  • PADF-HFP vinylidene fluoride-trifluoroethylene copoly
  • the modified compound of each homopolymer or copolymer refers to a modified compound obtained by copolymerizing a monomer unit in each homopolymer or copolymer with a monomer unit containing a specific functional group.
  • a fluorine-containing olefin monomer unit can be copolymerized with a compound containing a carboxyl functional group to obtain a modified compound thereof.
  • the first polymer particles have a number average molecular weight of 10,000 to 100,000, as measured by vapor phase osmometry.
  • the content of the first polymer particles in the coating is 0-15%, optionally 2%-15%, optionally 5-10%, based on the weight of the coating.
  • the coating contains 0%-30%, optionally 10-25%, and further optionally 15-20% of the second polymer particles, based on the weight of the coating.
  • the second polymer particles mainly play a bonding role and may include homopolymers or copolymers of unsaturated nitrile monomer units, homopolymers or copolymers of fluorine-containing olefin monomer units, homopolymers or copolymers of styrene monomer units, and one or more of the modified compounds of the above homopolymers or copolymers.
  • the second polymer particles may be one or more of polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), and polystyrene (PS).
  • PAN polyacrylonitrile
  • PVDF polyvinylidene fluoride
  • PS polystyrene
  • the second polymer particles have a number average molecular weight of 300,000 to 800,000, as measured by vapor phase osmometry.
  • the coating further comprises inorganic particles; optionally, the average volume particle size of the inorganic particles is 0.1-2 ⁇ m.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the average volume particle size D V50 of the inorganic particles is 0.1-2 ⁇ m, and optionally 0.3-0.7 ⁇ m.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the average volume particle size D v50 of the inorganic particles has a well-known meaning in the art and can be measured using instruments and methods known in the art. For example, it can be measured using a laser particle size analyzer (e.g., Master Size 3000) with reference to the particle size distribution laser diffraction method of GB/T 19077-2016.
  • a laser particle size analyzer e.g., Master Size 3000
  • the particle size and number average particle size of the organic particles can be tested using equipment and methods known in the art.
  • a scanning electron microscope such as ZEISS Sigma 300
  • SEM scanning electron microscope
  • multiple test samples for example, 10) may be taken to repeat the above test, and the average value of each test sample is taken as the final test result.
  • the inorganic particles include one or more of aluminum oxide (Al 2 O 3 ), boehmite ( ⁇ -AlOOH), barium titanate (BaTiO 3 ), titanium oxide (TiO 2 ), magnesium oxide (MgO), barium sulfate (BaSO 4 ), magnesium hydroxide (Mg(OH) 2 ), silicon dioxide (SiO 2 ), tin dioxide (SnO 2 ), calcium oxide (CaO), zinc oxide (ZnO), zirconium oxide (ZrO 2 ), yttrium oxide (Y 2 O 3 ), nickel oxide (NiO), cerium oxide (CeO 2 ), zirconium titanate (SrTiO 3 ), magnesium fluoride (MgF 2 ), clay, glass powder, boron nitride and aluminum nitride; for example, the inorganic particles may include one or more of aluminum oxide, boehmite, barium titanate, titanium oxide, magnesium oxide, clay, glass powder, boron
  • the content of the inorganic particles is 60% to 100%, based on the weight of the coating.
  • the coating comprises 65-80% inorganic particles, 6-12% first polymer particles, and 15-20% second polymer particles, based on the weight of the coating.
  • the coating may further include other organic compounds, for example, polymers, dispersants, wetting agents, other types of binders, etc. that improve heat resistance.
  • organic compounds for example, polymers, dispersants, wetting agents, other types of binders, etc. that improve heat resistance.
  • the above-mentioned other organic compounds are all non-granular substances in the coating.
  • the present application has no particular restrictions on the types of the above-mentioned other organic compounds, and any known material with good improved performance can be selected.
  • the present application has no particular restrictions on the material of the base film, and any known base film with good chemical stability and mechanical stability can be selected, such as one or more of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the base film can be a single-layer film or a multi-layer composite film. When the base film is a multi-layer composite film, the materials of each layer can be the same or different.
  • the thickness of the base film is 5-16 ⁇ m, and the thickness of the coating on one side is 1-10 ⁇ m, optionally 2-5 ⁇ m, measured using a scanning electron microscope. This can further ensure the wettability of the separator and the capacity of the negative electrode, so that the corresponding battery has good cycle performance.
  • the thickness of the coating layer is the vertical distance from the top of the protrusion formed by the first polymer particles to the horizontal line of the base film surface.
  • the ratio of the coating thickness on one side to the base film thickness is 0.1-1.5, optionally 0.25-1.0, and further optionally 0.4-0.85.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the air permeability (Gurley value) of the separator is less than or equal to 370s, optionally 100-250s, and further optionally 150-200s, measured by 100mL of gas permeation according to ASTM-D726 (B).
  • Gurley value the air permeability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the porosity of the coating is 20%-98%, optionally 25-40%, and further optionally 28-35%.
  • the wettability of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • the porosity of the separator is 20%-60%, optionally 30-40%, as measured according to ASTM D-2873.
  • ASTM D-2873 the porosity of the separator and the capacity of the negative electrode can be further guaranteed, so that the corresponding battery has good cycle performance.
  • a secondary battery is provided.
  • a secondary battery includes a positive electrode sheet, a negative electrode sheet, an electrolyte and a separator.
  • active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet.
  • the electrolyte plays the role of conducting ions between the positive electrode sheet and the negative electrode sheet.
  • the separator is set between the positive electrode sheet and the negative electrode sheet, mainly to prevent the positive and negative electrodes from short-circuiting, while allowing ions to pass through.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector, wherein the positive electrode film layer includes a positive electrode active material.
  • the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • aluminum foil may be used as the metal foil.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base layer.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • Polymer material substrate such as substrates of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.
  • lithium transition metal oxides may include, but are not limited to , lithium cobalt oxide (such as LiCoO2 ), lithium nickel oxide (such as LiNiO2 ), lithium manganese oxide (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333 ), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523 ) , LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211 ) , LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622 ), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05
  • lithium-containing phosphates with an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO 4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO 4 ), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.
  • lithium iron phosphate such as LiFePO 4 (also referred to as LFP)
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate
  • LiMnPO 4 lithium manganese phosphate and carbon
  • the positive electrode film layer may also optionally include a binder.
  • the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer and fluorine-containing acrylate resin.
  • PVDF polyvinylidene fluoride
  • PTFE polytetrafluoroethylene
  • PTFE polytetrafluoroethylene
  • the weight ratio of the binder in the positive electrode film layer is 0-20% by weight, based on the total weight of the positive electrode film layer.
  • the positive electrode film layer may further include a conductive agent.
  • the conductive agent may include at least one of superconducting carbon, carbon black (e.g., acetylene black or Ketjen black), carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the weight ratio of the conductive agent in the positive electrode film layer is 0-20% by weight, based on the total weight of the positive electrode film layer.
  • the positive electrode sheet can be prepared by the following method: the components for preparing the positive electrode sheet, such as the positive electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as N-methylpyrrolidone) to form a positive electrode slurry, wherein the positive electrode slurry has a solid content of 40-80wt%, and the viscosity at room temperature is adjusted to 5000-25000mPa ⁇ s, the positive electrode slurry is coated on the surface of the positive electrode collector, and after drying, the positive electrode sheet is formed by cold rolling; the compaction density of the positive electrode sheet is 2.0-3.6g/cm 3 , and can be optionally 2.3-3.5g/cm 3 .
  • a solvent such as N-methylpyrrolidone
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, wherein the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • copper foil may be used as the metal foil.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material substrate.
  • the composite current collector may be formed by forming a metal material on a polymer material substrate.
  • the metal material includes but is not limited to copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • the polymer material substrate includes but is not limited to polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE) and other substrates.
  • the negative electrode active material may adopt the negative electrode active material for batteries known in the art.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used.
  • These negative electrode active materials may be used alone or in combination of two or more.
  • the weight ratio of the negative electrode active material in the negative electrode film layer is 70-100% by weight, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, carbon black (e.g., acetylene black or Ketjen black), carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
  • the weight ratio of the conductive agent in the negative electrode film layer is 0-20% by weight, based on the total weight of the negative electrode film layer.
  • the negative electrode film layer may further include other additives, such as a thickener (such as sodium carboxymethyl cellulose (CMC-Na)), etc.
  • a thickener such as sodium carboxymethyl cellulose (CMC-Na)
  • the weight ratio of the other additives in the negative electrode film layer is 0-15% by weight, based on the total weight of the negative electrode film layer.
  • the negative electrode sheet can be prepared by the following method: the components for preparing the negative electrode sheet, such as the negative electrode active material, the conductive agent, the binder and any other components are dispersed in a solvent (such as deionized water) to form a negative electrode slurry, wherein the solid content of the negative electrode slurry is 30-70wt%, and the viscosity at room temperature is adjusted to 2000-10000mPa ⁇ s; the obtained negative electrode slurry is coated on the negative electrode current collector, and after a drying process, cold pressing such as rolling, a negative electrode sheet is obtained.
  • the compacted density of the negative electrode sheet is 0.5-2.0g/m 3 .
  • the mass M of the negative electrode active material per unit area of the negative electrode film layer can be obtained by weighing using a standard balance.
  • the thickness T of the negative electrode film layer can be measured by using a micrometer, for example, a Mitutoyo 293-100 micrometer with an accuracy of 0.1 ⁇ m. It should be noted that the thickness of the negative electrode film layer described in the present invention refers to the thickness of the negative electrode film layer in the negative electrode sheet used for assembling the battery after cold pressing and compaction.
  • the electrolyte plays the role of conducting ions between the positive electrode and the negative electrode.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or all-solid.
  • the electrolyte is an electrolyte solution, which includes an electrolyte salt and a solvent.
  • the electrolyte salt may be selected from one or more of lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluorooxalatoborate (LiDFOB), lithium dioxalatoborate (LiBOB), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorobis(oxalatophosphate) (LiDFOP) and lithium tetrafluorooxalatophosphate (LiTFOP).
  • concentration of the electrolyte salt is generally 0.5-5
  • the solvent can be selected from one or more of fluoroethylene carbonate (FEC), ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4-butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), ethyl methyl sulfone (EMS) and diethyl sulfone (FEC),
  • the electrolyte may further include additives, such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • additives such as negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain battery properties, such as additives that improve battery overcharge performance, additives that improve battery high or low temperature performance, etc.
  • the secondary battery further includes the isolation membrane described in the first aspect of the present application.
  • the isolation film has a thickness of 5-40 ⁇ m, and optionally 7-20 ⁇ m.
  • the positive electrode sheet, the negative electrode sheet, and the separator may be formed into an electrode assembly by a winding process or a lamination process.
  • the secondary battery may include an outer package that can be used to encapsulate the electrode assembly and the electrolyte.
  • the outer packaging of the secondary battery may be a hard shell, such as a hard plastic shell, an aluminum shell, a steel shell, etc.
  • the outer packaging of the secondary battery may also be a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
  • FIG1 is a secondary battery 5 of a square structure as an example.
  • the outer package may include a shell 51 and a cover plate 53.
  • the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the isolation film can form an electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is encapsulated in the receiving cavity.
  • the electrolyte is infiltrated in the electrode assembly 52.
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • secondary batteries may be assembled into a battery module.
  • the number of secondary batteries contained in the battery module may be one or more, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery module.
  • the plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module. Of course, they may also be arranged in any other manner. Further, the plurality of secondary batteries 5 may be fixed by fasteners.
  • the battery module may further include a housing having a housing space, and the plurality of secondary batteries 5 are housed in the housing space.
  • the battery modules described above may also be assembled into a battery pack.
  • the battery pack may contain one or more battery modules, and the specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
  • the battery pack may include a battery box and a plurality of battery modules disposed in the battery box.
  • the battery box includes an upper box body and a lower box body, and the upper box body can be covered on the lower box body to form a closed space for accommodating the battery modules.
  • the plurality of battery modules can be arranged in the battery box in any manner.
  • the present application also provides an electrical device, which includes at least one of the secondary battery, battery module, or battery pack provided in the present application.
  • the secondary battery, battery module, or battery pack can be used as a power source for the electrical device, and can also be used as an energy storage unit for the electrical device.
  • the electrical device may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
  • a secondary battery, a battery module or a battery pack may be selected according to its usage requirements.
  • FIG3 is an example of an electric device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
  • a battery pack or a battery module may be used.
  • a device may be a mobile phone, a tablet computer, a notebook computer, etc. Such a device is usually required to be thin and light, and a secondary battery may be used as a power source.
  • the positive electrode active material NCM811, the conductive carbon black SP and the binder PVDF were dispersed in the solvent NMP at a weight ratio of 98:1:1 and mixed evenly to obtain a positive electrode slurry with a solid content of 75%.
  • the positive electrode slurry was evenly coated on the positive electrode current collector aluminum foil, and after drying and cold pressing, a positive electrode sheet was obtained, and the coating amount per unit area was 0.39g/ 1540.25mm2 .
  • the negative electrode active material graphite and silicon dioxide SiO
  • the thickener sodium carboxymethyl cellulose the binder styrene butadiene rubber, and the conductive agent acetylene black are mixed in a mass ratio of 96.5:1:1:1, and deionized water is added to obtain a negative electrode slurry under the action of a vacuum mixer, wherein the solid content is 55%, wherein silicon dioxide SiO accounts for 5 weight % in the negative electrode active material
  • the negative electrode slurry is uniformly coated on a copper foil; the copper foil is dried at room temperature and then transferred to a 120°C oven for drying for 1 hour, and then cold pressed, and then cut to obtain a negative electrode sheet, wherein the coating amount per unit area is 0.2g/ 1540.25mm2 ; the thickness of the negative electrode film layer is 0.158mm.
  • step (3) The coating slurry prepared in step (2) is coated on one side of the PE substrate by a coating machine, and a release film is obtained by drying, slitting and other processes.
  • the line number of the gravure roller of the coating machine is 125 LPI
  • the coating speed is 50 m/min
  • the coating line speed ratio is 1.15
  • the drying temperature is 50°C
  • the drying time is 25 s.
  • the single-side coating weight per unit area on the release film is 2.3 g/ m2 .
  • the organic solvent is a mixed solution containing ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC), wherein the volume ratio of EC, EMC and DEC is 20:20:60.
  • EC ethylene carbonate
  • EMC ethyl methyl carbonate
  • DEC diethyl carbonate
  • the volume ratio of EC, EMC and DEC is 20:20:60.
  • argon atmosphere glove box with a water content of ⁇ 10ppm fully dried lithium salt LiPF6 is dissolved in the organic solvent and mixed evenly to obtain an electrolyte.
  • the concentration of the lithium salt is 1 mol/L.
  • the positive electrode sheet, isolation film, and negative electrode sheet are stacked in order, so that the isolation film is placed between the positive and negative electrode sheets to play an isolating role. Then, they are wound into a square bare battery cell, loaded with aluminum-plastic film, and then baked at 80°C to remove water. After that, 63g of the corresponding non-aqueous electrolyte is injected and sealed. After standing, hot and cold pressing, formation, clamping, capacity division and other processes, a finished battery with a capacity of 35Ah is obtained.
  • Example 1 The preparation steps of Example 1 were repeated, except that the thickness of the separator base film, the negative electrode surface density and the separator coating thickness were changed respectively, as shown in Table 1 for details.
  • Example 3 The preparation steps of Example 3 were repeated, except that in step (2) of preparing the isolation film 3), inorganic particles of aluminum oxide (Al 2 O 3 , Dv50 of 500 nm), first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer (number average molecular weight of 80,000), dispersant sodium carboxymethyl cellulose (CMC-Na), and wetting agent silicone-modified polyether were used in a weight ratio of 90:8:1:1.
  • Al 2 O 3 Al 2 O 3 , Dv50 of 500 nm
  • first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer number average molecular weight of 80,000
  • dispersant sodium carboxymethyl cellulose CMC-Na
  • wetting agent silicone-modified polyether were used in a weight ratio of 90:8:1:1.
  • Example 3 The preparation steps of Example 3 were repeated, except that in step (2) of preparing the isolation film 3), inorganic particles of aluminum oxide (Al 2 O 3 , Dv50 is 500 nm), first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer (number average molecular weight is 80,000), second polymer particles of polyvinylidene fluoride (number average molecular weight is 500,000), dispersant sodium carboxymethyl cellulose (CMC-Na), and wetting agent silicone modified polyether were used in a weight ratio of 75:8:15:1:1.
  • inorganic particles of aluminum oxide Al 2 O 3 , Dv50 is 500 nm
  • first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer number average molecular weight is 80,000
  • second polymer particles of polyvinylidene fluoride number average molecular weight is 500,000
  • dispersant sodium carboxymethyl cellulose C
  • Example 3 The preparation steps of Example 3 were repeated, except that in step (2) of preparing the isolation film 3), inorganic particles of aluminum oxide (Al 2 O 3 , Dv50 is 500 nm), first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer (number average molecular weight is 80,000), second polymer particles of polyvinylidene fluoride (number average molecular weight is 500,000), dispersant sodium carboxymethyl cellulose (CMC-Na), and wetting agent silicone modified polyether were used in a weight ratio of 68:10:20:1:1.
  • inorganic particles of aluminum oxide Al 2 O 3 , Dv50 is 500 nm
  • first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer number average molecular weight is 80,000
  • second polymer particles of polyvinylidene fluoride number average molecular weight is 500,000
  • dispersant sodium carboxymethyl cellulose
  • Example 3 The preparation steps of Example 3 were repeated, except that in step (2) of preparing the isolation membrane, inorganic particles of aluminum oxide (Al 2 O 3 , Dv50 of 500 nm), second polymer particles of polyvinylidene fluoride (number average molecular weight of 500,000), dispersant sodium carboxymethyl cellulose (CMC-Na), and wetting agent silicone-modified polyether were used in a weight ratio of 78:20:1:1.
  • inorganic particles of aluminum oxide Al 2 O 3 , Dv50 of 500 nm
  • second polymer particles of polyvinylidene fluoride number average molecular weight of 500,000
  • dispersant sodium carboxymethyl cellulose CMC-Na
  • wetting agent silicone-modified polyether were used in a weight ratio of 78:20:1:1.
  • Comparative Example 1 The value of V/C is higher than the protection range of the present invention
  • Example 1 The preparation steps of Example 1 were repeated, except that 1) the coating amount per unit area of the positive electrode sheet was 0.164 g/1540.25 mm2; 2) the coating amount per unit area of the negative electrode sheet was 0.084 g/1540.25 mm2; 3) in the preparation of the separator, the separator thickness used in step (1) was 12 ⁇ m, and the single-side coating weight per unit area on the separator in step (3) was 8 g/ m2 .
  • Example 10 The preparation steps of Example 10 were repeated, except that 1) the coating amount per unit area of the positive electrode plate was 0.57 g/1540.25 mm 2 ; 2) the coating amount per unit area of the negative electrode plate was 0.29 g/1540.25 mm 2 ; 3) in the preparation of the separator, the separator thickness used in step (1) was 5 ⁇ m, and in step (2), inorganic particles of aluminum oxide (Al 2 O 3 , Dv50 of 500 nm), first polymer particles of styrene-vinyl acetate-pyrrolidone copolymer (number average molecular weight of 80,000), second polymer particles of polyvinylidene fluoride (number average molecular weight of 500,000), dispersant sodium carboxymethyl cellulose (CMC-Na), and wetting agent silicone-modified polyether were used in a weight ratio of 94:2:2:1:1.
  • Al 2 O 3 , Dv50 of 500 nm aluminum oxide
  • the battery cell was fully discharged, and the negative electrode membrane was taken out by disassembling the battery cell in a vacuum dry environment. Then, the electrode was soaked in excess DMC for more than 2 hours, and dried in a vacuum drying oven above 60°C. In a dry environment, it was punched into discs with a diameter of 1.4 cm (area 1.5386 cm2).
  • a metal lithium sheet was used as the counter electrode, a ceglar composite membrane was used as the diaphragm, and an electrolyte was added to form a button cell.
  • the battery was charged and discharged using a LAND series battery tester to obtain the capacity C of the prepared disc.
  • V1 S ⁇ d (where S is the area of the electrode, which can be measured by length ⁇ width, in cm 2 ; d is the thickness of the diaphragm, which can be directly measured, in cm).
  • S the area of the electrode, which can be measured by length ⁇ width, in cm 2 ; d is the thickness of the diaphragm, which can be directly measured, in cm).
  • the batteries of the embodiments and comparative examples were prepared according to the above method, and various performance parameters were measured. The results are shown in Table 2 below.
  • the secondary battery of the present application has good cycle performance, and the initial discharge capacity is maintained at a high level.

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Abstract

本申请涉及一种二次电池，其包含负极极片和隔离膜，所述负极极片包含负极集流体和设置在所述负极集流体至少一侧的负极膜层；所述负极膜层单位面积的容量记为C，所述隔离膜单位面积的孔隙体积记为V，则所述二次电池满足：0.05cm 3/Ah≤V/C≤0.3cm 3/Ah，其中，C的单位为mAh，V的单位为cm 3；以及包括其的用电装置。所述二次电池具有良好的循环性能。

Description

二次电池和用电装置 技术领域
本申请涉及锂电池技术领域，尤其涉及一种二次电池和用电装置。
背景技术
近年来，二次电池被广泛应用于水力、火力、风力和太阳能电站等储能电源系统，以及电动工具、电动自行车、电动摩托车、电动汽车、军事装备、航空航天等多个领域。由于二次电池取得了极大的发展，因此对其能量密度、循环性能等也提出了更高的要求。如何进一步提升电池的使用性能，仍是本领域的技术人员不断努力的方向。
发明内容
本申请是鉴于上述课题而进行的，其目的在于，提供一种二次电池，其具有良好的循环性能。
为了达到上述目的，本申请的第一方面提供了一种二次电池，其包含负极极片和隔离膜，所述负极极片包含负极集流体和设置在所述负极集流体至少一侧的负极膜层；
所述负极膜层单位面积的容量记为C，所述隔离膜单位面积的孔隙体积记为V，则所述二次电池满足：0.05cm 3/Ah≤V/C≤0.3cm 3/Ah，其中，C的单位为mAh，V的单位为cm 3。
本申请的二次电池通过保证隔离膜的孔隙体积与负极膜层单位面积的容量的比值满足上述范围，保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，0.07cm 3/Ah≤V/C≤0.25cm 3/Ah；可选地，0.08cm 3/Ah≤V/C≤0.2cm 3/Ah。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，C为2-8mAh，可选为2.3-5.5mAh，进一步可选为2.3-5.0mAh。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，V为2×10 -4-20×10 -4cm 3，可选为2×10 -4-15×10 -4cm 3，进一步可选为4×10 -4-10×10 -4cm 3。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述负极膜层的面密度为0.002g/cm 2-0.02g/cm 2，可选为0.006-0.015g/cm 2，进一步可选为0.005-0.007g/cm 2。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述负极膜层的厚度为0.03-0.24mm；可选为0.08-0.16mm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述隔离膜包含基膜和设置在所述基膜的至少一侧的涂层，所述涂层包含第一聚合物颗粒和第二聚合物颗粒。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述第一聚合物颗粒的数均粒径大于第二聚合物颗粒的数均粒径。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述第一聚合物颗粒的数均粒径为2-8μm，可选为3-7μm；和/或，所述第二聚合物颗粒的数均粒径为50-800nm，可选的为100-600nm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述第一聚合物颗粒的含量小于等于15％，基于所述涂层的重量计；和/或，所述第二聚合物颗粒的含量小于等于30％，基于所述涂层的重量计。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述第一聚合物颗粒包括含氟烯基单体单元的均聚物或共聚物、烯烃基单体单元的均聚物或共聚物、不饱和腈类单体单元的均聚物或共聚物、环氧烷类单体单元的均聚物或共聚物、丙烯酸酯类单体单元的均聚物或共聚物、酰亚胺类单体单元的均聚物或共聚物以及上述各均聚物或共聚物的改性化合物中的至少一种；和/或，所述第二聚合物颗粒包括不饱和腈类单体单元的均聚物或共聚物，含氟烯基单体单元的均聚物或共聚物，苯乙烯类单体单元的均聚物或共聚物，以及上述各均聚物或共聚物的改性化合物中的至少一种。由此，可进一步保证隔离膜的浸润能力以 及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述涂层还包含无机颗粒；可选地，所述无机颗粒的平均体积粒径为0.1-2μm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述基膜的厚度为5-16μm；和/或，所述涂层的厚度为1-5μm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述其中一侧涂层厚度与基膜厚度的比值为0.1-1.5。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述隔离膜的透气率小于等于370s；可选为100-250s。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述隔离膜的孔隙率为20％-60％。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
本申请的第二方面还提供一种用电装置，其特征在于，包括本申请的第一方面所述的二次电池。
本申请的二次电池通过保证隔离膜的孔隙体积与负极膜层单位面积的容量的比值满足上述范围，保证隔离膜具有足够大的孔隙体积的同时负极膜层具有具有足够的单位面积的容量，使得相应的电池具有良好的循环性能。
附图说明
图1是本申请一实施方式的二次电池的示意图。
图2是图1所示的本申请一实施方式的二次电池的分解图。
图3是本申请一实施方式的二次电池用作电源的用电装置的示意图。
附图标记说明：
5、二次电池；51、壳体；52、电极组件；53、盖板；6、用电装置。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的二次电池和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的 详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或 A和B都为真(或存在)。
目前，目前，对隔离膜的改进通常为在在基膜上涂覆陶瓷涂层和/或粘接涂层。这种隔离膜在电池内部压力增长后由于粘接涂层被压扁压平，会阻挡隔离膜和极片之间的离子通道，对电解液浸润不足，甚至还会出现黑斑、析锂等问题。并且，对隔离膜的改进中也未考虑与正负极的配合作用。因此，现有的对二次电池的改进，特别是对隔离膜的改进需要进一步改进。发明人经过研究发现，二次电池中隔离膜的孔隙体积与负极膜层单位面积的容量构成特定关系的情况下，既保证隔离膜的浸润能力，又保证了负极的容量，从而使得相应的二次电池具有良好的循环性能。
二次电池
在一些实施方式中，本申请的第一方面提供了一种二次电池，其包含负极极片和隔离膜，所述负极极片包含负极集流体和设置在所述负极集流体至少一侧的负极膜层；
所述负极膜层单位面积的容量记为C，所述隔离膜单位面积的孔隙体积记为V，则所述二次电池满足：0.05cm 3/Ah≤V/C≤0.3cm 3/Ah，其中，C的单位为mAh，V的单位为cm 3。
本申请的二次电池通过保证隔离膜的孔隙体积与负极膜层单位面积的容量的比值满足上述范围，保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，C为负极膜层单位面积的容量，即每cm 2负极膜层(也可称为每cm 2负极极片)的容量。
在一些实施方式中，V为隔离膜单位面积的孔隙体积，即每cm 2隔离膜的孔隙体积。
在一些实施方式中，V/C可为0.05cm 3/Ah、0.07cm 3/Ah、0.08cm 3/Ah、0.09cm 3/Ah、0.1cm 3/Ah、0.15cm 3/Ah、0.18cm 3/Ah、0.20cm 3/Ah、0.24cm 3/Ah、0.25cm 3/Ah、0.28cm 3/Ah、0.3cm 3/Ah中的任意数值或者为上述任意两个数值组成的范围内。本领域技术人员可根据需要进行调整和选择。
在一些实施方式中，C为2-8mAh，可选为2.3-5.5mAh，进一步可选为2.3-5.0mAh；V为2-20×10 -4cm 3，可选为2-15×10 -4cm 3，进一步可选为4-10×10 -4cm 3。
在一些实施方式中，所述隔离膜单位面积的孔隙体积是隔离膜在电池内部自生压力下的孔隙体积；通常电池内部自生压力为0-10MPa。
在一些实施方式中，0.07cm 3/Ah≤V/C≤0.25cm 3/Ah，C为2-8mAh，V为2×10 - 4-20×10 -4cm 3。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，0.08cm 3/Ah≤V/C≤0.2cm 3/Ah，C为2-8mAh，V为2.5×10 -4-15×10 -4cm 3。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，0.08cm 3/Ah≤V/C≤0.3cm 3/Ah，C为2-8mAh，V为2-20×10 -4cm 3。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，0.07cm 3/Ah≤V/C≤0.25cm 3/Ah，C为2-8mAh，V为0.2×10 -3-1.2×10 -3cm 3。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，0.05cm 3/Ah≤V/C≤0.2cm 3/Ah，C为2-8mAh，V为0.16×10 -3-1.0×10 -3cm3。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，0.15cm 3/Ah≤V/C≤0.25cm 3/Ah，C为2.4-2.9mAh，V为0.4×10 -3-0.6×10 -3cm3。
在一些实施方式中，所述负极膜层的面密度为0.002-0.02g/cm 2，可选为0.006-0.015g/cm 2，进一步可选为0.005-0.007g/cm 2。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述负极膜层包含80-99％，可选为93-97％的负极活性材料，基于负极膜层的重量计。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述负极膜层的厚度为0.03-0.24mm；可选为0.08-0.16mm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述隔离膜包含基膜和设置在所述基膜的至少一侧的涂层，所述涂层包含第一聚合物颗粒和第二聚合物颗粒。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在任意的实施方式中，所述第一聚合物颗粒的数均粒径大于第二聚合物颗粒的数 均粒径。
在一些实施方式中，所述第一聚合物颗粒的数均粒径为2-8μm，可选为3-7μm；和/或，所述第二聚合物颗粒的数均粒径为50-800nm，可选的为100-600nm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述第一聚合物颗粒的含量小于等于15％，基于所述涂层的重量计；和/或，所述第二聚合物颗粒的含量小于等于30％，基于所述涂层的重量计。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述第一聚合物颗粒包括含氟烯基单体单元的均聚物或共聚物、烯烃基单体单元的均聚物或共聚物、不饱和腈类单体单元的均聚物或共聚物、环氧烷类单体单元的均聚物或共聚物、丙烯酸酯类单体单元的均聚物或共聚物、酰亚胺类单体单元的均聚物或共聚物以及上述各均聚物或共聚物的改性化合物中的至少一种；和/或，所述第二聚合物颗粒包括不饱和腈类单体单元的均聚物或共聚物，含氟烯基单体单元的均聚物或共聚物，苯乙烯类单体单元的均聚物或共聚物，以及上述各均聚物或共聚物的改性化合物中的至少一种。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，在所述涂层中，所述第一聚合物颗粒可以包括含氟烯基单体单元的均聚物或共聚物，烯烃基单体单元的均聚物或共聚物，不饱和腈类单体单元的均聚物或共聚物，环氧烷类单体单元的均聚物或共聚物，丙烯酸酯类单体单元的均聚物或共聚物，酰亚胺类单体单元的均聚物或共聚物，以及上述各均聚物或共聚物的改性化合物中的一种或几种。
在一些实施方式中，所述含氟烯基单体单元可选自二氟乙烯、偏二氟乙烯、三氟乙烯、三氟氯乙烯、四氟乙烯、六氟丙烯中的一种或几种。
在一些实施方式中，所述烯烃基单体单元可选自乙烯、丙烯、丁二烯、异戊二烯等中的一种或几种。
在一些实施方式中，所述不饱和腈类单体单元可选自丙烯腈、甲基丙烯腈等中的一种或几种。
在一些实施方式中，所述环氧烷类单体单元可选自环氧乙烷、环氧丙烷等中的一种或几种。
在一些实施方式中，所述丙烯酸酯类单体单元可以选自丙烯酸甲酯、丙烯酸乙酯、丙烯酸丙酯、丙烯酸丁酯、甲基丙烯酸甲酯、甲基丙烯酸丁酯、甲基丙烯酸异辛酯等中的一种或几种。
在一些实施方式中，所述第一聚合物颗粒可以包括聚四氟乙烯、聚三氟氯乙烯、聚氟乙烯、聚偏二氟乙烯、聚乙烯、聚丙烯、聚丙烯腈、聚环氧乙烷、聚丙烯酸酯、聚甲基丙烯酸酯、不同含氟烯基单体单元的共聚物、含氟烯基单体单元与烯烃基单体单元的共聚物、含氟烯基单体单元与丙烯酸类单体单元的共聚物、含氟烯基单体单元与丙烯酸酯类单体单元的共聚物、聚乙烯吡咯烷酮、聚酰亚胺、聚环氧乙烷(PEO)，以及上述各均聚物或共聚物的改性化合物中的一种或几种。
在一些实施方式中，所述第一聚合物颗粒可以包括聚丙烯腈(PAN)、聚甲基丙烯酸甲酯(PMMA)、偏二氟乙烯-三氟乙烯共聚物、偏二氟乙烯-六氟丙烯共聚物(PADF-HFP)、偏二氟乙烯-三氟乙烯-六氟丙烯共聚物、偏二氟乙烯-六氟丙烯-丙烯酸共聚物、偏二氟乙烯-六氟丙烯-丙烯酸酯共聚物、聚乙烯吡咯烷酮、聚酰亚胺、聚环氧乙烷(PEO)、苯乙烯-醋酸乙烯酯-吡咯烷酮共聚物，以及上述共聚物的改性化合物中的一种或几种。
根据一些实施例，所述各均聚物或共聚物的改性化合物是指将各均聚物或共聚物中的单体单元与含有特定官能团的单体单元共聚所得的改性化合物。例如，可以将含氟烯基单体单元与含羧基官能团的化合物共聚得到其改性化合物等。
在一些实施方式中，所述第一聚合物颗粒的数均分子量为1万-10万，根据气相渗透法测量。
在一些实施方式中，在所述涂层中，所述第一聚合物颗粒的含量为0-15％，可选为2％-15％，可选为5-10％，基于所述涂层的重量计。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述涂层包含0％-30％、可选为10-25％、进一步可选为15-20％的第二聚合物颗粒，基于所述涂层的重量计。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述第二聚合物颗粒主要起粘结作用，可包括不饱和腈类单体单元的均聚物或共聚物，含氟烯基单体单元的均聚物或共聚物，苯乙烯类单体单元的均聚物或共聚物，以及上述各均聚物或共聚物的改性化合物中的一种或几种。
在一些实施方式中，第二聚合物颗粒可以是聚丙烯腈(PAN)、聚偏二氟乙烯(PVDF)、聚苯乙烯(PS)中的一种或几种。
在一些实施方式中，所述第二聚合物颗粒的数均分子量为30万-80万，根据气相渗透法测量。
在一些实施方式中，所述涂层还包含无机颗粒；可选地，所述无机颗粒的平均体积粒径为0.1-2μm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述无机颗粒的平均体积粒径D V50为0.1-2μm，可选的为0.3-0.7μm。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在本申请中，无机颗粒的平均体积粒径D v50为本领域公知的含义，可采用本领域已知的仪器及方法进行测定。例如可以参照GB/T 19077-2016粒度分布激光衍射法，采用激光粒度分析仪(例如Master Size 3000)测定。
在本申请中，有机颗粒的粒径和数均粒径可以采用本领域已知的设备和方法进行测试。例如，使用扫描电子显微镜(例如ZEISS Sigma 300)，参考JY/T010-1996，获取隔离膜的扫描电子显微镜(SEM)图片。作为示例，可以按照如下方法测试：在隔离膜上任意选取一个长×宽＝50mm×100mm的测试样品，在测试样品中随机选取多个测试区域(例如5个)，并在一定放大倍率(例如测量第一种有机颗粒时为500倍，测量第二种有机颗粒时为1000倍)下，读取各测试区域中各有机颗粒的粒径(即：取有机颗粒上最远的两点间的距离作为该有机颗粒的粒径)，统计各测试区域中的有机颗粒的数量和粒径数值，取各测试区域中有机颗粒粒径的算术平均值，即为该测试样品中有机颗粒的数均粒径。为了确保测试结果的准确性，可以取多个测试样品(例如10个)重复进行上述测试，取各个测试样品的平均值作为最终的测试结果。
在一些实施方式中，所述无机颗粒包括可以包括氧化铝(Al 2O 3)、勃姆石(γ-AlOOH)、钛酸钡(BaTiO 3)、氧化钛(TiO 2)、氧化镁(MgO)、硫酸钡(BaSO 4)、氢氧化镁(Mg(OH) 2)、二氧化硅(SiO 2)、二氧化锡(SnO 2)、氧化钙(CaO)、氧化锌(ZnO)、氧化锆(ZrO 2)、氧化钇(Y 2O 3)、氧化镍(NiO)、氧化铈(CeO 2)、钛酸锆(SrTiO 3)、氟化镁(MgF 2)、粘土、玻璃粉末、氮化硼和氮化铝中的一种或几种；例如，所述无机颗粒可以包括氧化铝、勃姆石、钛酸钡、氧化钛、氧化镁、粘土、玻璃粉末、氮化硼和氮化铝中的一种或几种。 可选地，所述无机颗粒包括氧化铝(Al2O3)、勃姆石(γ-AlOOH)中的一种或几种。
在一些实施方式中，在所述涂层中，所述无机颗粒的含量为60％-100％，基于所述涂层的重量计。
在一个实施方式中，所述涂层包含65-80％的无机颗粒、6-12％的第一聚合物颗粒和15-20％的第二聚合物颗粒，基于所述涂层的重量计。
在一些实施方式中，所述涂层还可以包括其他有机化合物，例如，可以包括改善耐热性的聚合物、分散剂、润湿剂、其他种类的粘结剂等。上述其他有机化合物在涂层中均为非颗粒状的物质。本申请对上述其他有机化合物的种类没有特别的限制，可以选用任意公知的具有良好改善性能的材料。
本申请对所述基膜的材质没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的基膜，例如玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的一种或几种。所述基膜可以是单层薄膜，也可以是多层复合薄膜。当所述基膜为多层复合薄膜时，各层的材料可以相同，也可以不同。
在一些实施方式中，所述基膜的厚度为5-16μm，所述其中一侧涂层的厚度为1-10μm，可选为2-5μm，采用扫描电镜测量。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在本申请中，所述涂层的厚度为第一聚合物颗粒形成的凸起顶部至基膜表面水平线的垂直距离。
在一些实施方式中，所述其中一侧涂层厚度与基膜厚度的比值为0.1-1.5，可选为0.25-1.0，进一步可选为0.4-0.85。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述隔离膜的透气率(Gurley值)小于等于370s，可选为100-250s，进一步可选为150-200s，根据ASTM-D726(B)以100mL气体透过来测量。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述涂层的孔隙率为20％-98％，可选为25-40％，进一步可选为28-35％。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
在一些实施方式中，所述隔离膜的孔隙率为20％-60％，可选为30-40％，根据 ASTM D-2873测定。由此，可进一步保证隔离膜的浸润能力以及负极的容量，使得相应的电池具有良好的循环性能。
以下适当参照附图对本申请的二次电池和用电装置进行说明。
本申请的一个实施方式中，提供一种二次电池。
通常情况下，二次电池包括正极极片、负极极片、电解质和隔离膜。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。电解质在正极极片和负极极片之间起到传导离子的作用。隔离膜设置在正极极片和负极极片之间，主要起到防止正负极短路的作用，同时可以使离子通过。
正极极片
正极极片包括正极集流体以及设置在正极集流体至少一个表面的正极膜层，所述正极膜层包括正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极膜层设置在正极集流体相对的两个表面的其中任意一者或两者上。
在一些实施方式中，所述正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用铝箔。复合集流体可包括高分子材料基层和形成于高分子材料基层至少一个表面上的金属层。复合集流体可通过将金属材料形成在高分子材料基材上而形成。其中，金属材料包括但不限于铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等。高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)
在一些实施方式中，正极活性材料可包含本领域公知的用于电池的正极活性材料。作为示例，正极活性材料可包括以下材料中的至少一种：橄榄石结构的含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO 2)、锂镍氧化物(如LiNiO 2)、锂锰氧化物(如LiMnO 2、LiMn 2O 4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi 1/3Co 1/3Mn 1/3O 2(也可以简称为NCM 333)、LiNi 0.5Co 0.2Mn 0.3O 2(也可以简称为NCM 523)、LiNi 0.5Co 0.25Mn 0.25O 2(也可以简称为NCM 211)、LiNi 0.6Co 0.2Mn 0.2O 2(也可以简称为NCM 622)、LiNi 0.8Co 0.1Mn 0.1O 2(也可以简称为NCM 811)、锂镍钴铝氧化物(如 LiNi 0.85Co 0.15Al 0.05O 2)及其改性化合物等中的至少一种。橄榄石结构的含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO 4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO 4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施方式中，正极膜层还可选地包括粘结剂。作为示例，所述粘结剂可以包括聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物及含氟丙烯酸酯树脂中的至少一种。所述粘结剂在正极膜层中的重量比为0-20重量％，基于正极膜层的总重量计。
在一些实施方式中，正极膜层还可选地包括导电剂。作为示例，所述导电剂可以包括超导碳、炭黑(例如乙炔黑或科琴黑)、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。所述导电剂在正极膜层中的重量比为0-20重量％，基于正极膜层的总重量计。
在一些实施方式中，可以通过以下方式制备正极极片：将上述用于制备正极极片的组分，例如正极活性材料、导电剂、粘结剂和任意其他的组分分散于溶剂(例如N-甲基吡咯烷酮)中，形成正极浆料，其中所述正极浆料固含量为40-80wt％，室温下的粘度调整到5000-25000mPa·s，将正极浆料涂覆在正极集流体的表面，烘干后经过冷轧机冷压后形成正极极片；正极极片压实密度为2.0-3.6g/cm 3，可选为2.3-3.5g/cm 3。
负极极片
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料形成在高分子材料基材上而形成。其中，金属材料包括但不限于铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等，高分子材料基材包括但不限于聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等基材。
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。所述负极活性材料在负极膜层中的重量比为70-100重量％，基于负极膜层的总重量计。
在一些实施方式中，负极膜层还可选地包括粘结剂。所述粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。所述粘结剂在负极膜层中的重量比为0-30重量％，基于负极膜层的总重量计。
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、炭黑(例如乙炔黑或科琴黑)、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。所述导电剂在负极膜层中的重量比为0-20重量％，基于负极膜层的总重量计。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。所述其他助剂在负极膜层中的重量比为0-15重量％，基于负极膜层的总重量计。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料，其中所述负极浆料固含量为30-70wt％，室温下的粘度调整到2000-10000mPa·s；将所得到的负极浆料涂覆在负极集流体上，经过干燥工序，冷压例如对辊，得到负极极片。负极极片压实密度0.5-2.0g/m 3。
单位面积负极膜层中负极活性物质的质量M的可使用标准天平称量得到。
负极膜层的厚度T可采用万分尺测量得到，例如可使用型号为Mitutoyo293-100、精度为0.1μm的万分尺测量得到。需要说明的是，本发明所述的负极膜层厚度是指经冷压压实后并用于组装电池的负极极片中的负极膜层的厚度。
电解质
电解质在正极极片和负极极片之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施方式中，电解质盐可选自六氟磷酸锂(LiPF 6)、四氟硼酸锂(LiBF 4)、高氯酸锂(LiClO 4)、六氟砷酸锂(LiAsF 6)、双氟磺酰亚胺锂(LiFSI)、双三氟甲磺酰亚胺锂(LiTFSI)、三氟甲磺酸锂(LiTFS)、二氟草酸硼酸锂(LiDFOB)、二草酸硼酸锂(LiBOB)、二氟磷酸锂(LiPO 2F 2)、二氟二草酸磷酸锂(LiDFOP)及四氟草酸磷酸锂(LiTFOP)中的一种或几种。所述电解质盐的浓度通常为0.5-5mol/L。
在一些实施方式中，溶剂可选自氟代碳酸乙烯酯(FEC)、碳酸亚乙酯(EC)、碳酸亚丙基酯(PC)、碳酸甲乙酯(EMC)、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)、碳酸亚丁酯(BC)、甲酸甲酯(MF)、乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(PA)、丙酸甲酯(MP)、丙酸乙酯(EP)、丙酸丙酯(PP)、丁酸甲酯(MB)、丁酸乙酯(EB)、1,4-丁内酯(GBL)、环丁砜(SF)、二甲砜(MSM)、甲乙砜(EMS)及二乙砜(ESE)中的一种或几种。
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
隔离膜
在一些实施方式中，二次电池中还包括本申请第一方面所述的隔离膜。
在一些实施方式中，所述隔离膜的厚度为5-40μm，可选为7-20μm。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
在一些实施方式中，二次电池可包括外包装。该外包装可用于封装上述电极组件及电解质。
在一些实施方式中，二次电池的外包装可以是硬壳，例如硬塑料壳、铝壳、钢壳等。二次电池的外包装也可以是软包，例如袋式软包。软包的材质可以是塑料，作为塑料，可列举出聚丙烯、聚对苯二甲酸丁二醇酯以及聚丁二酸丁二醇酯等。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图1是作为一个示例的方形结构的二次电池5。
在一些实施方式中，参照图2，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于所述开口，以封闭所述容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于所述容纳腔内。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
在一些实施方式中，二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。
在电池模块中，多个二次电池5可以是沿电池模块的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。
可选地，电池模块还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。
在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。
在电池包中可以包括电池箱和设置于电池箱中的多个电池模块。电池箱包括上箱体和下箱体，上箱体能够盖设于下箱体，并形成用于容纳电池模块的封闭空间。多个电池模块可以按照任意的方式排布于电池箱中。
另外，本申请还提供一种用电装置，所述用电装置包括本申请提供的二次电池、电池模块、或电池包中的至少一种。所述二次电池、电池模块、或电池包可以用作所述用电装置的电源，也可以用作所述用电装置的能量存储单元。所述用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。
作为所述用电装置，可以根据其使用需求来选择二次电池、电池模块或电池包。
图3为一个用电装置的示例。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对二次电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为另一个示例的装置可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用二次电池作为电源。
实施例
为了使本申请所解决的技术问题、技术方案及有益效果更加清楚，以下将结合实施例和附图对本申请进行进一步详细说明。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。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付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。
实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
一、实施例
实施例1
1)正极极片的制备
将正极活性材料NCM811、导电炭黑SP及粘结剂PVDF按照重量比98:1:1分散至溶剂NMP中进行混合均匀，得到正极浆料，其固含量为75％；将正极浆料均匀涂布于正极集流体铝箔上，经烘干、冷压后，得到正极极片，其单位面积的涂覆量为0.39g/1540.25mm 2。
2)负极极片的制备
将负极活性材料(石墨和氧化亚硅SiO)、增稠剂羧甲基纤维素钠、粘接剂丁苯橡胶、导电剂乙炔黑，按照质量比96.5:1:1:1进行混合，加入去离子水，在真空搅拌机作用下获得负极浆料，其固含量为55％，其中氧化亚硅SiO在负极活性材料中占5重量％；将负极浆料均匀涂覆在铜箔上；将铜箔在室温晾干后转移至120℃烘箱干燥1h，然后进行冷压，然后分切得到负极片，其单位面积的涂覆量为0.2g/1540.25mm 2；负极膜层的厚度为0.158mm。
3)隔离膜的制备
(1)提供PE基材，基材的厚度为7μm，孔隙率为37％；
(2)配制涂层浆料：将无机颗粒三氧化二铝(Al 2O 3，Dv50为500nm)、分散剂羧甲基纤维素钠(CMC-Na)、润湿剂有机硅改性聚醚按照重量比98：1：1在去离子水中混合均匀，得到固含量为38％(按重量计)的涂层浆料。
(3)将步骤(2)配制的涂层浆料用涂布机涂布在PE基材的一侧表面上，通过干燥、分切等工序，得到隔离膜。其中，涂布机的凹版辊的线数为125LPI，涂布的速度为50m/min，涂布的线速比为1.15，干燥温度为50℃，干燥时间为25s。单位面积的隔离膜上的单面涂层重量为2.3g/m 2。
4)电解液的制备
有机溶剂为含有碳酸亚乙酯(EC)、碳酸甲乙酯(EMC)和碳酸二乙酯(DEC)的混液，其中，EC、EMC和DEC的体积比为20:20:60。在含水量<10ppm的氩气气氛手套箱中，将充分干燥的锂盐LiPF6溶解于有机溶剂中，混合均匀，获得电解液。其中，锂盐的浓度为1mol/L。
5)电池的制备
将正极片、隔离膜、负极片按顺序叠好，使隔离膜处于正、负极片之间起到隔离的作用，再卷绕成方形的裸电芯后，装入铝塑膜，然后在80℃下烘烤除水后，注入63g相应的非水电解液、封口，经静置、热冷压、化成、夹具、分容等工序后，得到容量为35Ah的成品电池。
实施例2-8
重复实施例1的制备步骤，不同之处在于各自改变隔膜基膜厚度、负极面密度和隔膜涂层厚度，详见表1。
实施例9
重复实施例3的制备步骤，不同之处在于在3)隔离膜的制备中步骤(2)中使用无机颗粒三氧化二铝(Al 2O 3，Dv50为500nm)、第一聚合物颗粒苯乙烯-醋酸乙烯酯-吡咯烷酮共聚物(数均分子量为8万)、分散剂羧甲基纤维素钠(CMC-Na)、润湿剂有机硅改性聚醚按照重量比90：8：1：1。
实施例10
重复实施例3的制备步骤，不同之处在于在3)隔离膜的制备中步骤(2)中使用 无机颗粒三氧化二铝(Al 2O 3，Dv50为500nm)、第一聚合物颗粒苯乙烯-醋酸乙烯酯-吡咯烷酮共聚物(数均分子量为8万)、第二聚合物颗粒聚偏氟乙烯(数均分子量为50万)、分散剂羧甲基纤维素钠(CMC-Na)、润湿剂有机硅改性聚醚按照重量比75：8：15：1：1。
实施例11
重复实施例3的制备步骤，不同之处在于在3)隔离膜的制备中步骤(2)中使用无机颗粒三氧化二铝(Al 2O 3，Dv50为500nm)、第一聚合物颗粒苯乙烯-醋酸乙烯酯-吡咯烷酮共聚物(数均分子量为8万)、第二聚合物颗粒聚偏氟乙烯(数均分子量为50万)、分散剂羧甲基纤维素钠(CMC-Na)、润湿剂有机硅改性聚醚按照重量比68：10：20：1：1。
实施例12
重复实施例3的制备步骤，不同之处在于在3)隔离膜的制备中步骤(2)中使用无机颗粒三氧化二铝(Al 2O 3，Dv50为500nm)、第二聚合物颗粒聚偏氟乙烯(数均分子量为50万)、分散剂羧甲基纤维素钠(CMC-Na)、润湿剂有机硅改性聚醚按照重量比78：20：1：1。
对比例1：V/C的数值高于本发明的保护范围内
重复实施例1的制备步骤，不同之处在于在1)正极极片的单位面积的涂敷量为0.164g/1540.25mm2；2)负极极片的单位面积的涂覆量为0.084g/1540.25mm2；3)隔离膜的制备中步骤(1)中使用隔膜厚度为12μm，步骤(3)中单位面积的隔离膜上的单面涂层重量为8g/m 2。
对比例2
重复实施例10的制备步骤，不同之处在于1)正极极片的单位面积的涂敷量为0.57g/1540.25mm 2；2)负极极片的单位面积的涂覆量为0.29g/1540.25mm 2；3)隔离膜的制备中步骤(1)中使用隔膜厚度为5μm，步骤(2)中使用无机颗粒三氧化二铝(Al 2O 3，Dv50为500nm)、第一聚合物颗粒苯乙烯-醋酸乙烯酯-吡咯烷酮共聚物(数均分子量为8万)、第二聚合物颗粒聚偏氟乙烯(数均分子量为50万)、分散剂羧甲基纤维素钠(CMC-Na)、润湿剂有机硅改性聚醚按照重量比94：2：2：1：1。
各实施例和对比例的产品参数汇总于表1。
Figure PCTCN2022134218-appb-000001
二、性能测试
1.循环性能测试
将电池置于25℃烘箱中，静置2h后进行充放电测试。0.5C电流恒流充电到4.25V，继续恒压充电，直至充电电流小于0.05C后截止；暂停30min；0.5C电流恒流放电到2.5V；暂停30min，记录相应的放电容量为初始放电容量。以上为电池的一个充放电循环，不断重复，直至电池容量衰减到初始值的80％，记录循环圈数。
2.负极膜层单位面积的容量C的测试方法
将电芯满放，在真空干燥环境将电芯拆解取出负极膜片，然后用过量的DMC将极片浸泡2h以上，取出后经过60℃以上真空干燥箱烘干，在干燥环境中冲切成之直径1.4cm的圆片(面积1.5386cm2)，在手套箱中以金属锂片为对电极，隔膜选用ceglard复合膜，加入电解液组成扣式电池，运用LAND蓝电系列电池测试仪对电池进行充放电测试，得到制备的圆片的容量C。
3.隔离膜单位面积的孔隙体积V的测试方法
将待测隔膜裁剪成一定长宽尺寸的方形样品。测量并计算样品的表观体积V1，V1＝S×d(其中，S为极片面积可用长×宽测得，单位cm 2；d为隔膜厚度可直接测得，单位cm)。采用AccuPycⅡ1340真密度仪，参考GB/T 24586-2009中孔隙率测试方法，利用氦气置换法，结合阿基米德原理和玻尔定律(PV＝nRT)，精确测量被测材料的真实体积V2，单位cm 3，孔隙体积V＝V1-V2。
三、各实施例、对比例测试结果
按照上述方法分别制备各实施例和对比例的电池，并测量各项性能参数，结果见下表2。
表2各实施例和对比例的电池的性能
编号 快充循环圈数 初始放电容量
1 500圈 35Ah
2 600圈 34.5Ah
3 700圈 34.2Ah
4 800圈 33.5Ah
5 1100圈 31Ah
6 1300圈 29.5Ah
7 1400圈 28Ah
8 1500圈 27Ah
9 1200圈 32Ah
10 1400圈 32.3Ah
11 1500圈 33Ah
12 1200圈 33Ah
对比例1 1500圈 26Ah
对比例2 200圈 35.5Ah
通过上述实施例和对比例可得知，本申请的二次电池具有良好的循环性能，并且初始放电容量保持在较高水平。
需要说明的是，本申请不限定于上述实施方式。上述实施方式仅为示例，在本申请的技术方案范围内具有与技术思想实质相同的构成、发挥相同作用效果的实施方式均包含在本申请的技术范围内。此外，在不脱离本申请主旨的范围内，对实施方式施加本领域技术人员能够想到的各种变形、将实施方式中的一部分构成要素加以组合而构筑的其它方式也包含在本申请的范围内。

Claims (17)

  1. 一种二次电池，其包含负极极片和隔离膜，所述负极极片包含负极集流体和设置在所述负极集流体至少一侧的负极膜层；
    所述负极膜层单位面积的容量记为C，所述隔离膜单位面积的孔隙体积记为V，则所述二次电池满足：0.05cm 3/Ah≤V/C≤0.3cm 3/Ah，其中，C的单位为mAh，V的单位为cm 3。
  2. 根据权利要求1所述的二次电池，其特征在于，0.07cm 3/Ah≤V/C≤0.25cm 3/Ah；可选地，0.08cm 3/Ah≤V/C≤0.2cm 3/Ah。
  3. 根据权利要求1或2所述的二次电池，其特征在于，C为2-8mAh，可选为2.3-5.5mAh，进一步可选为2.3-5.0mAh。
  4. 根据权利要求1-3中任一项所述的二次电池，其特征在于，V为2×10 -4-20×10 - 4cm 3，可选为2×10 -4-15×10 -4cm 3，进一步可选为4×10 -4-10×10 -4cm 3。
  5. 根据权利要求1-4中任一项所述的二次电池，其特征在于，所述负极膜层的面密度为0.002g/cm 2-0.02g/cm 2，可选为0.006-0.015g/cm 2，进一步可选为0.005-0.007g/cm 2。
  6. 根据权利要求1-5中任一项所述的二次电池，其特征在于，所述负极膜层的厚度为0.03-0.24mm；可选为0.08-0.16mm。
  7. 根据权利要求1-6中任一项所述的二次电池，其特征在于，所述隔离膜包含基膜和设置在所述基膜的至少一侧的涂层，所述涂层包含第一聚合物颗粒和第二聚合物颗粒。
  8. 根据权利要求7所述的二次电池，其特征在于，所述第一聚合物颗粒的数均粒径大于第二聚合物颗粒的数均粒径。
  9. 根据权利要求7或8所述的二次电池，其特征在于，所述第一聚合物颗粒的数均粒径为2-8μm，可选为3-7μm；和/或，所述第二聚合物颗粒的数均粒径为50-800nm，可选的为100-600nm。
  10. 根据权利要求7-9中任一项所述的二次电池，其特征在于，所述第一聚合物颗粒的含量小于等于15％，基于所述涂层的重量计；和/或，所述第二聚合物颗粒的含量小于等于30％，基于所述涂层的重量计。
  11. 根据权利要求7-10中任一项所述的二次电池，其特征在于，所述第一聚合物颗粒包括含氟烯基单体单元的均聚物或共聚物、烯烃基单体单元的均聚物或共聚物、不 饱和腈类单体单元的均聚物或共聚物、环氧烷类单体单元的均聚物或共聚物、丙烯酸酯类单体单元的均聚物或共聚物、酰亚胺类单体单元的均聚物或共聚物以及上述各均聚物或共聚物的改性化合物中的至少一种；和/或，所述第二聚合物颗粒包括不饱和腈类单体单元的均聚物或共聚物，含氟烯基单体单元的均聚物或共聚物，苯乙烯类单体单元的均聚物或共聚物，以及上述各均聚物或共聚物的改性化合物中的至少一种。
  12. 根据权利要求7-11中任一项所述的二次电池，其特征在于，所述涂层还包含无机颗粒；可选地，所述无机颗粒的平均体积粒径为0.1-2μm。
  13. 根据权利要求7-12中任一项所述的二次电池，其特征在于，所述基膜的厚度为5-16μm；和/或，所述涂层的厚度为1-5μm。
  14. 根据权利要求7-13中任一项所述的二次电池，其特征在于，所述其中一侧涂层厚度与基膜厚度的比值为0.1-1.5。
  15. 根据权利要求1-14中任一项所述的二次电池，其特征在于，所述隔离膜的透气率小于等于370s；可选为100-250s。
  16. 根据权利要求1-15中任一项所述的二次电池，其特征在于，所述隔离膜的孔隙率为20％-60％。
  17. 一种用电装置，其特征在于，包括选自权利要求1-16中任一项所述的二次电池。
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CN103579663A (zh) * 2012-07-24 2014-02-12 株式会社日立制作所 锂离子二次电池
CN104995783A (zh) * 2012-12-28 2015-10-21 株式会社理光 非水电解质蓄电元件
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CN115104219A (zh) * 2020-11-30 2022-09-23 宁德时代新能源科技股份有限公司 一种隔离膜、其制备方法及其相关的二次电池、电池模块、电池包和装置

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CN103579663A (zh) * 2012-07-24 2014-02-12 株式会社日立制作所 锂离子二次电池
CN104995783A (zh) * 2012-12-28 2015-10-21 株式会社理光 非水电解质蓄电元件
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