WO2018040903A1 - 锂离子电池隔膜及其制备方法和锂离子电池 - Google Patents

锂离子电池隔膜及其制备方法和锂离子电池 Download PDF

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WO2018040903A1
WO2018040903A1 PCT/CN2017/097404 CN2017097404W WO2018040903A1 WO 2018040903 A1 WO2018040903 A1 WO 2018040903A1 CN 2017097404 W CN2017097404 W CN 2017097404W WO 2018040903 A1 WO2018040903 A1 WO 2018040903A1
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acrylate
self
copolymer
segment
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English (en)
French (fr)
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胡家玲
刘荣华
单军
何龙
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比亚迪股份有限公司
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Priority to EP17845205.8A priority Critical patent/EP3490031A1/en
Priority to KR1020197004848A priority patent/KR20190042576A/ko
Priority to US16/319,911 priority patent/US20190237732A1/en
Priority to JP2019511573A priority patent/JP2019525439A/ja
Publication of WO2018040903A1 publication Critical patent/WO2018040903A1/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
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/454—Separators, membranes or diaphragms characterised by the material having a layered structure comprising a non-fibrous layer and a fibrous layer superimposed on one another
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/005—Reinforced macromolecular compounds with nanosized materials, e.g. nanoparticles, nanofibres, nanotubes, nanowires, nanorods or nanolayered materials
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/417—Polyolefins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H01M50/434—Ceramics
    • H—ELECTRICITY
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    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/44—Fibrous material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/457—Separators, membranes or diaphragms characterised by the material having a layered structure comprising three or more layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • H01M50/461—Separators, membranes or diaphragms characterised by their combination with electrodes with adhesive layers between electrodes and separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2305/00—Condition, form or state of the layers or laminate
    • B32B2305/30—Fillers, e.g. particles, powders, beads, flakes, spheres, chips
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/30—Properties of the layers or laminate having particular thermal properties
    • B32B2307/306—Resistant to heat
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present disclosure relates to the field of lithium ion batteries, and in particular to a lithium ion battery separator, a method of preparing the same, and a lithium ion battery.
  • Lithium-ion batteries are mainly composed of positive/negative materials, electrolytes, separators and battery casing packaging materials.
  • the separator is an important component of the lithium ion battery. It is used to separate the positive and negative electrodes, prevent the internal short circuit of the battery, allow the electrolyte ions to pass freely, and complete the electrochemical charging and discharging process.
  • the performance of the diaphragm determines the interface structure and internal resistance of the battery, which directly affects the rate performance, cycle performance and safety performance (high temperature resistance) of the battery.
  • the separator with excellent performance plays an important role in improving the overall performance of the battery.
  • the industry is called the "third electrode" of the battery.
  • the existing lithium ion battery separator can be formed by a polymer material by a humidity phase inversion method, however, the melting temperature of the polymer material is generally low (400-500 ° C), which may cause poor resistance to high temperature performance of the lithium ion battery, and The polymer material cannot adsorb impurities such as side reaction products generated in the battery.
  • the prior art employs a heat-resistant layer formed of inorganic particles and a binder to improve the heat resistance of the lithium ion battery separator.
  • CN103474610A discloses a method for preparing a composite lithium ion battery separator by electrospinning/electrostatic spraying.
  • the specific steps of the method are as follows: (1) adding a high molecular polymer to an organic solvent, mechanically stirring and dissolving to form a transparent Solution, preparing electrospinning solution; (2) mixing inorganic nanoparticles and high molecular polymer into an organic solvent, mechanically stirring to obtain an inorganic nanoparticle suspension; (3) spinning prepared in step (1)
  • the lower nanofiber membrane is prepared by electrospinning of silk liquid, and the inorganic nanoparticle suspension prepared in step (2) is electrostatically sprayed onto the lower nanofiber membrane to form an intermediate layer, and finally, a layer of static electricity is received on the inorganic particle layer.
  • the mass ratio of the inorganic nanoparticles to the high molecular polymer in the step (2) is (0.8-0.98): (0.2-0.02).
  • this product does not really improve the stability of the composite separator at higher temperatures, mainly because the polymer used is one or two of PMMA, PAN, PVDF and P (VDF-HFP). a mixture of the above, wherein PMMA The melting point is 130-140 ° C, the glass transition temperature of polyacrylonitrile PAN is about 90 ° C, the carbonization temperature is about 200 ° C, the melting point of PVDF is 170 ° C, can not improve the heat shrinkage of the membrane at high temperature (> 180 ° C) The role.
  • the method comprises the steps of: preparing a fiber membrane by electrospinning, then preparing an inorganic-organic composite layer by electrostatic spraying, and then electrospinning the surface of the inorganic-organic composite layer to prepare a fiber layer, so that The formed structure has low tensile strength and puncture strength under normal conditions, and PVDF-HFP swells in the electrolyte, failing to protect.
  • the purpose of the present disclosure is to provide a novel lithium ion battery separator, a method of preparing the same, and a lithium ion battery.
  • the existing heat-resistant layer formed of inorganic particles and polymer materials since the heat resistance of the inorganic particles is superior to that of the commonly used polymer materials, in order to improve the high temperature resistance of the lithium ion battery separator, the existing ones In the heat-resistant layer, inorganic particles are usually used as a main component, and the polymer material content is low and only serves as a binder.
  • the bonding property of the high-temperature polymer binder high melting point
  • the low-temperature polymer binder low melting point
  • the inventors of the present disclosure have found through intensive research that the heat-resistant layer of the prior art can improve the heat resistance of the separator of the lithium ion battery to a certain extent, but the heat shrinkage at a high temperature is very large, which leads to inorganic The rupture of the particles reduces the high temperature strength.
  • the inventors of the present disclosure have also found through intensive research that when a high temperature resistant polymer is used as a main component of the heat resistant layer, and an inorganic material is used as a modified material of the heat resistant layer, the two are mixed in a specific ratio and then electrospun.
  • the way of the filament is such that when the heat-resistant layer is formed into a fiber network structure, the fiber formed by the high temperature resistant polymer serves as a skeleton to support the strength of the separator at a high temperature, and the added inorganic nanoparticles are equivalent to one anchor anchor fiber further enhanced
  • the corresponding lithium ion battery separator not only has high ionic conductivity, but also can improve heat resistance and mechanical strength at high temperatures. Based on this, the present disclosure has been completed.
  • the present disclosure provides a lithium ion battery separator, wherein the lithium ion battery separator includes a porous base film and a heat resistant layer covering at least one side surface of the porous base film;
  • the high temperature resistant polymer and the inorganic nanoparticle are contained, and the heat resistant layer has a fiber network structure.
  • the present disclosure also provides a method for preparing a lithium ion battery separator, the method comprising:
  • the present disclosure also provides a lithium ion battery, wherein the lithium ion battery includes a positive electrode, a negative electrode, an electrolyte, and a lithium ion battery separator between the positive and negative electrodes, the lithium ion battery separator being the lithium Ion battery separator.
  • the lithium ion battery separator provided by the present disclosure not only has good stability at high temperature (>160 ° C), but also has high heat shrinkage rate at high temperature, and high mechanical strength at high temperature, and composite diaphragm obtained by simply using high temperature resistant polymer spinning.
  • the heat resistance and high temperature mechanical strength are much better, while the common ceramic (CCL) separator exhibits a large heat shrinkage at high temperatures due to the use of a heat resistant polymer, or the polymer melts at a high temperature and the ceramic particles are between
  • the loose connection is made so that the entire lithium ion battery separator does not have high mechanical strength.
  • the preparation process of the lithium ion battery separator provided by the present disclosure is relatively simple, and the obtained lithium ion battery separator has better flexibility and is easy to wind up.
  • Figure 1 is a scanning electron micrograph of the heat-resistant layer obtained in Example 1, the magnification is 10000;
  • Example 2 is a scanning electron micrograph of the heat-resistant layer obtained in Example 1, and the magnification is 5000.
  • the lithium ion battery separator provided by the present disclosure includes a porous base film and a heat resistant layer covering at least one surface of the porous base film; the heat resistant layer contains a high temperature resistant polymer and inorganic nanoparticles, and the resistant
  • the thermal layer has a fibrous network structure.
  • the weight ratio of the high temperature resistant polymer to the inorganic nano material is 100: (3-50); optionally the high temperature resistance
  • the weight ratio of polymer to inorganic nanomaterial is 100: (5-18).
  • the heat resistant layer is composed of a high temperature resistant polymer and an inorganic nano material, optionally 100% by weight of the total heat resistant layer, wherein the content of the heat resistant polymer is 85-95% by weight, The content of the inorganic nanomaterial is 5 to 15% by weight.
  • the present disclosure is not particularly limited to the thickness and fiber diameter of the heat-resistant layer.
  • the one-side thickness of the heat-resistant layer may be selected from 0.5 to 30 ⁇ m.
  • the average diameter of the fibers in the heat-resistant layer may be selected from 100 to 2000 nm.
  • the heat resistant layer optionally has a single face density of 0.2 to 15 g/m 2 , for example, 1 to 5 g/m 2 .
  • the areal density refers to the mass of the material applied to the substrate membrane per unit area, and the amount of the dressing on the substrate membrane can be known from this index.
  • the electrical conductivity can be effectively ensured, the lithium ion migration is not affected, and the bonding performance is better, which is beneficial to improving the safety performance of the battery.
  • the heat resistant layer has a porosity of 80% or more, for example, 80 to 90%, such as 80 to 85%.
  • the porosity of the heat-resistant layer is within the above-mentioned optional range, the ionic conductivity of the lithium ion battery separator can be effectively ensured.
  • the method for measuring the porosity of the heat-resistant layer comprises: cutting a specific volume of the heat-resistant layer sample, weighing, and then immersing the heat-resistant layer sample in isobutanol, and measuring the sample after adsorption equilibrium weight,
  • the heat resistant layer is formed by electrospinning a spinning solution containing a high temperature resistant polymer and inorganic nanoparticles.
  • the type of the high temperature resistant polymer is not particularly limited, and may be any of various existing polymers having high temperature resistance.
  • the high temperature polymer may have a melting point of not lower than 180 ° C. For example, it is 200-600 °C.
  • the high temperature resistant polymer include, but are not limited to, polyetherimide (PEI), polyimide (PI), polyetheretherketone (PEEK), polyethersulfone (PES), polyamideimide. At least one of (PAI), polyamic acid (PAA), and polyvinylpyrrolidone (PVP).
  • polyetheretherketone (PEEK) includes copolyetheretherketone (CoPEEK) and modified (homopoly) polyetheretherketone.
  • the high temperature resistant polymer is selected from at least one of polyetherimide (PEI) and polyetheretherketone (PEEK).
  • PEI polyetherimide
  • PEEK polyetheretherketone
  • the fiber formed by the high temperature resistant polymer can be used as a skeleton to support the strength of the separator at a high temperature, and by cooperation with the inorganic particles, The heat shrinkage of the separator at a high temperature and the heat resistance of the composite separator can be further reduced, and the prepared battery separator has good heat resistance and good mechanical strength at high temperatures.
  • the present disclosure is not particularly limited to the particle diameter and kind of the inorganic nanoparticles.
  • the inorganic nanoparticles have an average particle diameter of 50 nm to 3 ⁇ m, for example, 50 nm to 1 ⁇ m, such as 50 nm to 0.4 ⁇ m.
  • the inorganic nanoparticles include, but are not limited to, Al 2 O 3 , SiO 2 , BaSO 4 , TiO 2 , CuO, MgO, LiAlO 2 , ZrO 2 , CNT, BN, SiC, Si 3 N 4 , WC, BC.
  • the present disclosure is not particularly limited to the thickness of the heat-resistant layer, and the optional one-sided thickness is 1-5 ⁇ m, for example, 1-3 ⁇ m.
  • the heat-resistant layer may be located on one side of the porous base film, or the heat-resistant layer may be provided on both sides of the porous base film.
  • the heat-resistant layer is disposed on both sides of the porous base film.
  • a lithium ion battery separator wherein the porous base film may be a polymer separator or a ceramic separator, which is the same as a ceramic separator conventional in the art, and includes a polymer separator and is located in the polymerization. a ceramic layer on the surface of the separator; wherein the above polymer separator can be an existing polyolefin separator.
  • the polyolefin separator is a general-purpose separator for a lithium ion battery, and includes a polypropylene (PP) separator, a polyethylene (PE) separator, and a PE/PP/PE three-layer separator.
  • the porous base film is optionally a ceramic separator in the present disclosure, and the heat resistant layer is located on a surface of the ceramic separator on a side where the ceramic layer is formed.
  • the ceramic layer in the ceramic separator according to the present disclosure there is no particular requirement for the ceramic layer in the ceramic separator according to the present disclosure, and a ceramic layer conventionally employed in the art can be selected.
  • the ceramic layer contains ceramic particles and a binder, and the areal density ⁇ of the ceramic layer at a unit thickness (1 ⁇ m) satisfies 1.8mg / cm 2 ⁇ 2.7mg / cm 2, satisfies the optional 1.85mg / cm 2 ⁇ 2.65mg / cm 2 , for example, meet 1.9mg / cm 2 ⁇ 2.6mg / cm 2 .
  • the ceramic membrane of the present disclosure is provided, by using the density per unit thickness of the face (1 m) in the control 1.8mg / cm 2 ⁇ 2.7mg / cm 2 of the ceramic layer can be improved high-temperature heat-shrinkable ceramic separator, When the heat resistance temperature is above 160 ° C, the thermal stability energy is improved without increasing the thickness of the ceramic layer, thereby not affecting the energy density of the battery.
  • the binder is contained in an amount of 2 to 8 parts by weight with respect to 100 parts by weight of the ceramic particles in the ceramic layer, optionally 4-6 parts by weight.
  • the content of each substance in the ceramic layer is controlled within the above range, the obtained ceramic separator can be made to have better high temperature heat shrinkage resistance.
  • the ceramic layer 2-8 parts by weight of the binder, 0.3- is included with respect to 100 parts by weight of the ceramic particles.
  • the surface treatment agent is contained in an amount of from 0.5 to 1.2 parts by weight based on 1.5 parts by weight.
  • the ceramic particles in the ceramic layer may include, but are not limited to, Al 2 O 3 (including ⁇ , ⁇ , ⁇ type), SiO 2 , BaSO 4 , BaO, titanium dioxide (TiO 2 , rutile or Anatase), CuO, MgO, Mg(OH) 2 , LiAlO 2 , ZrO 2 , carbon nanotubes (CNT), BN, SiC, Si 3 N 4 , WC, BC, AlN, Fe 2 O 3 , BaTiO 3 At least one of MoS 2 , ⁇ –V 2 O 5 , PbTiO 3 , TiB 2 , CaSiO 3 , molecular sieve (ZSM-5), clay, boehmite and kaolin, optionally using Al 2 O 3 , SiO 2 and At least one of BaSO 4 .
  • the inorganic particles are Al 2 O 3 (especially ⁇ -Al 2 O 3 ), SiO 2 or BaSO 4 , it has excellent thermal insulation and electrochemical stability, and is more favorable for improving the thermal stability of the lithium ion battery separator. To improve the safety of the battery.
  • the inventors of the present disclosure have found through extensive experiments that the heat-resistant layer provided by the present disclosure has better affinity with the above-mentioned ceramic separator than the polymer separator; meanwhile, the surface of the ceramic layer in the ceramic separator is uneven and has a large amount.
  • the particle protrusions can provide more adhesion points for the heat-resistant layer, which is beneficial to improve the bonding strength of the heat-resistant layer on the inorganic particle layer.
  • the heat-resistant layer can better bond the positive and negative electrodes and the separator as a whole.
  • the ceramic diaphragm has higher dimensional stability and higher heat shrink resistance.
  • the hardness of the prepared lithium ion battery can be improved by blending with the above-mentioned inorganic particle layer, and the pole piece is not easily deformed during circulation, and the safety is high.
  • the particle diameter is from 200 to 800 nm, alternatively from 300 nm to 600 nm.
  • the inventors of the present disclosure have found that when the particle diameter of the inorganic particles in the inorganic particle layer is within the above range, not only the agglomeration of the slurry for forming the ceramic layer but also the gas permeability of the ceramic separator can be effectively prevented.
  • the selection of the binder in the ceramic layer can be referred to conventional selection in the art.
  • it may be a polyacrylate, a copolymer of polyvinylidene fluoride and hexafluoropropylene, a copolymer of polyvinylidene fluoride and trichloroethylene, a polyacrylonitrile, a polyvinylpyrrolidone, a polyimide, a polyvinyl alcohol, or the like. At least one of them may be a polyacrylate such as a polyacrylate having a glass transition temperature of -40 ° C to 0 ° C.
  • a polyacrylate having a glass transition temperature of -40 ° C to 0 ° C specifically methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate At least one of a homopolymer, a copolymer, and the like.
  • a polyacrylate having a glass transition temperature of -40 ° C to 0 ° C is used as a binder, the processing property can be improved without affecting the bonding strength of the ceramic separator, and the industrial application prospect is further improved.
  • a crosslinkable monomer such as hydroxymethyl and/or methylol acrylamide may be optionally introduced into the above polyacrylate binder, and the content of the crosslinkable monomer may be optionally controlled to be bonded.
  • a crosslinkable monomer such as hydroxymethyl and/or methylol acrylamide
  • the content of the crosslinkable monomer may be optionally controlled to be bonded.
  • the present disclosure is not particularly limited to the type of the dispersant in the ceramic layer, and may be any of various materials which contribute to the dispersion of each substance in the slurry of the ceramic layer and have a number average molecular weight of 50,000 or less and optionally 5,000 to 20,000.
  • optional polyacrylic acid At least one of a salt, a polyethylene glycol ether, a silicate compound, a phosphate compound, and a guar gum, and optionally at least one of a polyacrylate, a polyethylene glycol ether, and a phosphate compound .
  • the polyacrylate may be, for example, at least one of potassium polyacrylate, sodium polyacrylate, lithium polyacrylate, and the like.
  • the polyethylene glycol ether may, for example, be polyethylene glycol tert-octylphenyl ether and/or polyethylene glycol monolauryl ether.
  • the phosphate compound may be, for example, sodium trimetaphosphate and/or sodium hexametaphosphate.
  • the present disclosure is not particularly limited to the kind of the thickener in the ceramic layer, and may be at least one selected from the group consisting of polyacrylate, polyvinylpyrrolidone, cellulose compound and polyacrylamide, and optionally polyacrylic acid or acrylic acid copolymerization. At least one of a substance and a cellulose compound.
  • the polyacrylate may be, for example, at least one of potassium polyacrylate, sodium polyacrylate, lithium polyacrylate, and the like.
  • the acrylic copolymer refers to a copolymer of acrylic acid and another monomer, and may be, for example, at least one of a copolymer of acrylic acid and styrene, a copolymer of acrylic acid and ethyl acrylate, a copolymer of acrylic acid and ethylene, and the like.
  • the cellulose compound may be, for example, at least one of sodium carboxymethylcellulose, potassium carboxymethylcellulose, hydroxyethylcellulose, and the like.
  • the viscosity of the 1% by weight aqueous solution of the thickener is 1500-7000 mPa ⁇ s, which can be well dispersed in the ceramic layer slurry, and is favorable for coating, and is more favorable for the improvement of the areal density.
  • both the dispersant and the thickener may be polyacrylates
  • the number average molecular weight of the polyacrylate as a thickener is much higher than the molecular weight of the polyacrylate as a dispersant, as a thickener.
  • the number average molecular weight of the polyacrylate is usually from 300,000 to 1.5 million, and the polyacrylate having a dispersant has a number average molecular weight of 50,000 or less.
  • the present disclosure is not particularly limited in the kind of the surface treatment agent, and may be selected from the group consisting of 3-glycidoxypropyltrimethoxysilane and/or 3-glycidoxypropyltriethoxysilane.
  • the interaction between the ceramic particles and the binder can be further improved to increase the strength of the ceramic separator.
  • the polymer separator in the ceramic separator has a thickness of 5 to 30 ⁇ m, for example, 6 to 25 ⁇ m.
  • the ceramic layer may have a single-sided thickness of 1-5 ⁇ m, for example, 2-3.5 ⁇ m, which is more advantageous for the improvement of the high-temperature heat shrinkage resistance of the ceramic separator and the improvement of the gas permeability.
  • the lithium ion battery separator further includes an adhesive layer formed on an outermost side of at least one side surface of the lithium ion battery separator, The formation of the bonding layer can improve the viscosity between the lithium ion battery separator and the positive and negative electrodes, increase the stability of the lithium ion battery separator, improve the safety performance of the battery, and further improve the ionic conductivity of the lithium ion battery separator.
  • the bonding layer contains an acrylate crosslinked polymer and a styrene-acrylate crosslinked copolymer, and/or a vinylidene fluoride-hexafluoropropylene copolymer, and The porosity of the bonding layer is 40-65%.
  • the ceramic separator further includes the above specific adhesive layer, it not only has good heat-resistant heat shrinkage, but also has higher bond strength and ionic conductivity.
  • the tie layer contains an acrylate crosslinked polymer and a styrene-acrylate crosslinked copolymer and/or a vinylidene fluoride-hexafluoropropylene copolymer
  • the adhesive layer contains an acrylate Crosslinked polymer and styrene-acrylate Crosslinking copolymer without vinylidene fluoride-hexafluoropropylene copolymer, or containing acrylate crosslinked polymer and vinylidene fluoride-hexafluoropropylene copolymer without styrene-acrylate crosslinked copolymer
  • it may contain an acrylate crosslinked polymer and a styrene-acrylate crosslinked copolymer and a vinylidene fluoride-hexafluoropropylene copolymer.
  • copolymer emulsion containing self-crosslinking type pure acrylic emulsion and self-crosslinking type styrene-acrylic emulsion and/or vinylidene fluoride and hexafluoropropylene can also be similarly explained.
  • the acrylate crosslinked polymer refers to a polymer obtained by crosslinking polymerization of a reactive acrylate monomer.
  • the acrylate crosslinked polymer may have a degree of crosslinking of 2 to 30%, alternatively 5 to 20%.
  • the degree of crosslinking refers to the percentage of the weight of the crosslinked polymer to the total weight of the polymer.
  • the glass transition temperature of the acrylate-based crosslinked polymer may be -20 ° C to 60 ° C, for example, -12 ° C to 54 ° C.
  • the acrylate crosslinked polymer is a second acrylate based crosslinked polymer, a third acrylate based crosslinked polymer, or a first acrylate based crosslinked polymer and a second a mixture of an acrylate-based crosslinked polymer and/or a third acrylate-based crosslinked polymer; wherein the first acrylate-based crosslinked polymer contains 70-80% by weight of a polymethyl methacrylate segment 2-10% by weight of a polyethyl acrylate segment, 10-20% by weight of a polybutyl acrylate segment and 2-10% by weight of a polyacrylic acid segment, the second acrylate crosslinked polymer containing 30-40% by weight of polymethyl methacrylate segment, 2-10% by weight of polyethyl acrylate segment, 50-60% by weight of polybutyl acrylate segment and 2-10% by weight of polyacrylic acid chain
  • the third acrylate crosslinked polymer contains 50-80% by weight of polymethyl methacrylate segment,
  • the first acrylate-based cross-linked polymer The glass transition temperature of the compound is from 50 ° C to 60 ° C, the glass transition temperature of the second acrylate crosslinked polymer is from -20 ° C to -5 ° C, and the third acrylate crosslinked polymer The glass transition temperature is from 30 ° C to 50 ° C.
  • the styrene-acrylate crosslinked copolymer refers to a copolymer obtained by copolymerization of a styrene monomer and a reactive acrylate monomer.
  • the weight ratio of the styrene structural unit to the acrylate structural unit in the styrene-acrylate crosslinked copolymer may be from 0.5 to 2:1, optionally from 0.67 to 1.5:1.
  • the styrene-acrylate crosslinked copolymer may have a degree of crosslinking of 2 to 30%, alternatively 5 to 20%.
  • the glass transition temperature of the styrene-acrylate crosslinked copolymer may be selected from -30 ° C to 50 ° C, for example, from -20 ° C to 50 ° C.
  • the styrene-acrylate crosslinked copolymer contains 40 to 50% by weight of a polystyrene segment, 5 to 15% by weight of a polymethyl methacrylate segment, 2 to 10 % by weight of polyethyl acrylate segment, 30-40% by weight of polybutyl acrylate segment and 2-10% by weight of polyacrylic acid segment; glass transition of the styrene-acrylate crosslinked copolymer The temperature is 15-30 °C.
  • the glass transition temperature of the vinylidene fluoride-hexafluoropropylene copolymer may be selected from -65 ° C to -40 ° C, for example, from -60 ° C to -40 ° C.
  • the vinylidene fluoride-hexafluoropropylene copolymer contains 80 to 98% by weight of a polyvinylidene fluoride segment and 2 to 20% by weight of a polyhexafluoropropylene segment, optionally containing 90- 96% by weight of polyvinylidene fluoride segments and 4-10
  • the weight percent of the polyhexafluoropropylene segment; the vinylidene fluoride-hexafluoropropylene copolymer has a glass transition temperature of from -60 ° C to -40 ° C.
  • the adhesive layer contains an acrylate-based crosslinked polymer and a styrene-acrylate cross-linked copolymer and does not contain a vinylidene fluoride-hexafluoropropylene copolymer, and the acrylate-based copolymer
  • the weight ratio of the cross-polymer to the styrene-acrylate cross-linking copolymer is 1:0.05-2, optionally 1:1-2; or the bonding layer contains an acrylate cross-linked polymer and a partial a fluoroethylene-hexafluoropropylene copolymer and no styrene-acrylate crosslinked copolymer, the weight ratio of the acrylate crosslinked polymer to the vinylidene fluoride-hexafluoropropylene copolymer is 1:0.3-25 , optionally 1:0.4-19; or, the bonding layer contains an acrylate crosslinked polymer, a styrene-acrylate cross
  • the bonding layer contains a first acrylate-based crosslinked polymer, a second acrylate-based cross-linked polymer, and a styrene-acrylate cross-linked copolymer and does not contain vinylidene fluoride - a hexafluoropropylene copolymer, and the weight ratio of the first acrylate crosslinked polymer, the second acrylate crosslinked polymer to the styrene-acrylate crosslinked copolymer is 5-10:1:10 -13; or,
  • the adhesive layer contains a first acrylate-based crosslinked polymer, a second acrylate-based cross-linked polymer, and a vinylidene fluoride-hexafluoropropylene copolymer, and does not contain a styrene-acrylate cross-linked copolymer.
  • the weight ratio of the first acrylate crosslinked polymer, the second acrylate crosslinked polymer and the vinylidene fluoride-hexafluoropropylene copolymer is 5-15:1:5-12; or
  • the adhesive layer contains a second acrylate crosslinked polymer and a vinylidene fluoride-hexafluoropropylene copolymer and does not contain a styrene-acrylate crosslinked copolymer, and the second acrylate crosslinked polymer
  • the weight ratio to the vinylidene fluoride-hexafluoropropylene copolymer is 1:5-20; or,
  • the adhesive layer comprises a second acrylate crosslinked polymer, a styrene-acrylate crosslinked copolymer and a vinylidene fluoride-hexafluoropropylene copolymer, the second acrylate crosslinked polymer, benzene
  • the weight ratio of the ethylene-acrylate crosslinked copolymer to the vinylidene fluoride-hexafluoropropylene copolymer is 1:0.5-2:1-5; or
  • the adhesive layer contains a third acrylate crosslinked polymer, a styrene-acrylate crosslinked copolymer, and a vinylidene fluoride-hexafluoropropylene copolymer, the third acrylate crosslinked polymer, benzene
  • the weight ratio of the ethylene-acrylate crosslinked copolymer to the vinylidene fluoride-hexafluoropropylene copolymer is 1:0.5-2:1-5; or
  • the adhesive layer comprises a first acrylate crosslinked polymer, a second acrylate crosslinked polymer, a styrene-acrylate crosslinked copolymer, and a vinylidene fluoride-hexafluoropropylene copolymer, the first acrylic acid
  • the weight ratio of the ester crosslinked polymer, the second acrylate crosslinked polymer, the styrene-acrylate crosslinked copolymer and the vinylidene fluoride-hexafluoropropylene copolymer is 10-15:1:0.5-2:5-10;
  • the first acrylate-based crosslinked polymer contains 70-80% by weight of polymethyl methacrylate segment, 2-10% by weight of polyethyl acrylate segment, and 10-20% by weight of polyacrylic acid.
  • the second acrylate-based crosslinked polymer containing 30 to 40% by weight of a polymethyl methacrylate segment, 2 to 10% by weight of a poly Ethyl acrylate segment, 50-60% by weight of polybutyl acrylate segment and 2-10% by weight of polyacrylic acid segment
  • the third acrylate crosslinked polymer contains 50-80% by weight of polymethyl a methyl acrylate segment, 2 to 10% by weight of a polyethyl acrylate segment, 15 to 40% by weight of a polybutyl acrylate segment, and 2 to 10% by weight of a polyacrylic acid segment, the styrene-acrylic acid
  • the ester crosslinked copolymer contains
  • the bonding layer further contains at least one of an acrylonitrile-acrylate copolymer, a chloropropene copolymer, and a styrene-butadiene copolymer.
  • the adhesive layer further contains an acrylonitrile-acrylate copolymer
  • the adhesive layer further contains a chloropropane copolymer and/or butylbenzene copolymer
  • the weight ratio of the acrylonitrile-acrylate copolymer to the acrylate crosslinked polymer may be 0.05-2:1, for example, 0.08. -1.85:1.
  • the weight ratio of the chloropropane copolymer to the acrylate crosslinked polymer may be from 0.15 to 7:1, for example, from 0.2 to 6:1.
  • the weight ratio of the styrene-butadiene copolymer to the acrylate-based cross-linked polymer may be selected from 0.05 to 2:1, for example, from 0.08 to 1.85:1.
  • the single layer density of the bonding layer may be selected from 0.05 to 0.9 mg/cm 2 , for example, from 0.1 to 0.6 mg/cm 2 .
  • the one-sided thickness of the bonding layer may be selected from 0.1 to 1 ⁇ m, for example from 0.2 to 0.6 ⁇ m.
  • the method for preparing a lithium ion battery separator provided by the present disclosure includes the following steps:
  • the solvent in the spinning solution is used to dissolve the high temperature resistant polymer and disperse the inorganic nanoparticles for the smooth realization of the subsequent electrospinning process.
  • the solvent may be any of various existing inert liquid substances capable of achieving the above purposes, and specific examples thereof include, but are not limited to, N-methylpyrrolidone (NMP), N'N-dimethylformamide (DMF), N. At least one of 'N-dimethylacetamide (DMAC), toluene, acetone, tetrahydrofuran, and the like.
  • the solvent may be used in an amount such that the concentration of the high temperature resistant polymer in the obtained spinning solution is from 5 to 30% by weight, alternatively from 8 to 25% by weight.
  • concentration of the spinning solution is a decisive factor affecting the entanglement of the molecular chain in the solution under certain other conditions.
  • the polymer solution can be divided into three types: polymer dilute solution, sub-concentrated solution and concentrated solution according to the difference in concentration and molecular chain morphology. In the dilute solution, the molecular chains are separated from each other and the distribution is uniform. As the concentration of the solution increases, the molecular chains interpenetrate and entangle.
  • the boundary concentration of the dilute solution and the sub-concentrated solution is called the contact concentration, and refers to the concentration at which the molecular chain contacts as the concentration of the solution increases, and then overlaps.
  • the boundary concentration of the concentrated solution and the concentrated solution is called the entanglement concentration, and refers to the concentration at which the molecular chains interpenetrate and entangle each other as the concentration of the solution further increases.
  • the spinning solution concentration is within the above optional range, the yarn forming performance can be effectively ensured.
  • the concentration of the spinning solution increases, the degree of entanglement of the polymer increases, and the filament formation property is better.
  • the basic principle of electrospinning is well known to those skilled in the art, in particular by applying a voltage between the spraying device and the receiving device, forming a jet from the spinning solution originating from the end of the cone of the spraying device, and being trapped in the electric field. Stretching, eventually forming fibers on the receiving device.
  • the receiving device comprises a drum (rotatable) or a receiving plate.
  • the electrospinning method generally includes a needle spinning method and a needleless spinning method, and specific processes are well known to those skilled in the art and will not be described herein.
  • the flow rate of the spinning solution may be selected from 0.3 to 5 mL/h, for example, 0.6 to 2 mL/h; and the spinning temperature may be selected from 25 to 70 ° C, for example, 30-50 ° C; spinning humidity can be selected from 2% to 60%, for example, 2% to 50%; the spinning voltage can be selected from 5 to 25 kV, for example, 8 to 20 kV.
  • the flow rate is within the above-mentioned optional range, it is ensured that a suitable fiber diameter is obtained, and at the same time, the needle can be effectively prevented from being occluded, and the spinning can be smoothly performed.
  • the control of the flow rate within the above range can obtain a fibrous layer having excellent porosity and bonding properties.
  • the spinning temperature and humidity are within the above range, it is combined with the above-mentioned mixed solvent to ensure that the fibers obtained by spinning are smoothly dried after being formed into silk, avoiding the adhesion of the fibers, resulting in a decrease in porosity, and avoiding the bonding property of the fiber layer. decline.
  • the spinning solution can be effectively excited to form a jet, thereby generating an effective stretching effect in the electric field, obtaining a fiber of a suitable diameter, ensuring the shape of the formed fiber, and facilitating the improvement of the porosity and viscosity of the fiber layer.
  • the receiving device can be selected as a drum, and the rotational speed of the drum can be selected from 100 to 6000 rpm, for example from 1000 to 2000 rpm.
  • the formed fibers are tightly attached to the surface of the collecting device in a circumferential manner, the fibers are deposited in the same direction, and are substantially in a straight state, that is, a fiber bundle which is straight and extends in the same direction.
  • the surface speed of the surface of the collecting device is too large, the fiber jet is broken due to the excessively fast receiving speed, and continuous fibers cannot be obtained.
  • the speed of the collecting device is 100-6000 rpm, a fiber bundle having straight straight-direction extension can be obtained.
  • the rotational speed of the collecting device is 1000-2000 rpm, the morphology of the fibers in the obtained fibrous layer is better, which is more advantageous for improving the mechanical strength of the fibrous layer.
  • the spinning conditions may include: a temperature of 25-70 ° C, a humidity of 2%-60%, and a liquid pool moving speed of 0-2000 mm/sec.
  • the moving speed of the material is 0-20000mm/min (the collecting device is plate-shaped, not rotating at this time) or the rotating speed of the drum is 100-6000rpm (the collecting device is the drum), and the positive voltage (the voltage at the source end of the fiber) is 0-150kV.
  • the negative voltage (voltage of the collecting device) is -50 to 0 kV, and the voltage difference (the voltage difference between the source end and the collecting device) is 10-100 kV; the optional includes: the temperature is 30-50 ° C, and the humidity is 2% - 50%, the moving speed of the liquid pool is 100-400mm/sec, the moving speed of the substrate is 1000-15000mm/min or the rotating speed of the drum is 1000-2000rpm, the positive voltage is 10-40kV, the negative voltage is -30-0kV, and the voltage difference is 20-60kV.
  • the inventors of the present disclosure have found through a large number of experiments that under the premise of the above-mentioned optional range in the spinning solution, the high temperature polymer concentration can achieve a good match between the solvent volatilization rate and the fiber formation speed by the electrospinning process under the above conditions. , a fiber layer having better morphology, higher adhesion, better adhesion between silk and silk in the heat-resistant layer, and a porosity of 80% or more, optionally 80-90%, for example, can be obtained, for example, It is 80-85%.
  • the present disclosure is not particularly limited to the fiber diameter and thickness in the heat-resistant layer, and may be specifically modified by controlling specific process conditions.
  • the fiber has an average diameter of 100-2000 nm, and the heat-resistant layer is The thickness of one side is 0.5-30 ⁇ m.
  • the fiber layer prepared by the above method has a single face density of 0.2 to 15 g/m 2 .
  • the above electrospinning may be performed on one side of the porous base film or on both sides of the porous base film.
  • the heat-resistant layer is formed on both sides of the porous base film by electrospinning.
  • the electrospinning is first performed on the side of the porous base film, and the hot rolling is selectively performed and dried, and then electrospinning is performed on the other side of the porous base film, and the hot rolling is selectively performed and dried.
  • the film is removed, and the film pressing treatment can be selectively performed at 50-120 ° C and 0.5-15 MPa, for example, hot rolling (the hot rolling condition is: temperature 50- 60 ° C, pressure 1-15 MPa), and then blast dried at 50 ° C for 24 h.
  • hot rolling the hot rolling condition is: temperature 50- 60 ° C, pressure 1-15 MPa
  • the porous base film may be selected from a ceramic separator including a polymer separator and a ceramic layer on a surface of the polymer separator; a heat resistant layer formed on the ceramic On the surface of the ceramic layer in the diaphragm.
  • the ceramic layer using the ceramic separator contains a feature of the inorganic particle layer, so that the heat resistant layer The surface of the ceramic layer can be more firmly bonded, and on the one hand, the peel strength of the prepared lithium ion battery separator can be effectively improved.
  • the inorganic particle layer is located between the polymer separator and the heat-resistant layer, and can impart lithium.
  • the ion battery separator has excellent heat shrinkage resistance as a whole.
  • the method for preparing the ceramic separator in the step S1 comprises: S11, providing a polymer separator; S12, and the ceramic particles, the binder, the dispersing agent and the thickening agent are in a weight ratio of 100: (2-8) : (0.3-1): a ratio of (0.5-1.8) is stirred and mixed to obtain a ceramic layer slurry, and the ceramic layer slurry is coated on at least one side surface of the polymer separator, and dried to obtain a ceramic layer;
  • the number average molecular weight of the dispersant is 50,000 or less.
  • the stirring rotation speed may be selected from 3000 to 10000 rpm, optionally 3000-9000rpm.
  • the density of the ceramic layer is more favorable.
  • the ceramic particles, the binder, the dispersant and the thickener are mixed in the above weight ratio, when the amount of the dispersant is less than 0.3 parts by weight and/or the thickener
  • the amount is less than 0.5 part by weight (relative to 100 parts by weight of the ceramic particles, the same applies hereinafter)
  • the dispersibility of the ceramic layer slurry may be insufficient, and it is difficult to form a high-density packing to obtain 1.8 mg/cm 2 of the present disclosure ⁇ ⁇ 2.7.
  • the areal density of mg/cm 2 when the dispersant is used in an amount of more than 1 part by weight and/or the thickener is used in an amount of more than 1.8 parts by weight, the gas permeability of the lithium ion battery separator may be affected to affect the battery output characteristics. .
  • the amount of the binder is less than 2 parts by weight, the bond strength may be insufficient; when the amount of the binder is more than 8 parts by weight, the gas permeability of the lithium ion battery separator may be seriously affected.
  • the number average molecular weight of the dispersant is higher than 50,000, the dispersion effect of the ceramic layer slurry may be affected, and the areal density may be lowered.
  • the ceramic particles, the binder, the dispersant and the thickener are in a weight ratio of 100:(4-6):(0.4-0.8):(0.7- 1.5) Mix and mix in proportion.
  • the amount of each substance in the ceramic layer slurry is controlled within the above optional range, the obtained ceramic layer can have a higher areal density and better high temperature heat shrinkage resistance.
  • the ceramic layer slurry further contains a surface treatment agent
  • the surface treatment agent is 3-glycidoxypropyltrimethoxysilane and/or 3-glycidyloxypropyl group.
  • Triethoxysilane which further improves the interaction between the ceramic particles and the binder, and enhances the strength of the ceramic layer.
  • the surface treatment agent may be used in an amount of 1.5 parts by weight or less, alternatively 0.5 to 1.2 parts by weight, based on 100 parts by weight of the ceramic particles, which is more advantageous for the improvement of the gas permeability of the ceramic layer.
  • the ceramic layer slurry obtained by mixing in step S12 is further A surfactant such as sodium dodecylbenzenesulfonate may be contained, and the amount of these surfactants may be conventionally selected in the art, and those skilled in the art will recognize that it will not be described herein.
  • a surfactant such as sodium dodecylbenzenesulfonate may be contained, and the amount of these surfactants may be conventionally selected in the art, and those skilled in the art will recognize that it will not be described herein.
  • step S12 comprises stirring the ceramic particles, the dispersant and the thickener at a high speed of 3000-10000 rpm for 0.5-3 hours, adding a surface treatment agent and continuing to stir for 0.5-3 hours.
  • the ceramic layer is formed on both surfaces of the polymer separator in step S12.
  • the amount of the ceramic layer slurry may be selected such that the ceramic layer has a single-sided thickness of 1-5 ⁇ m, optionally 2-3.5 ⁇ m, which is more favorable for the ceramic layer. Improvement in heat shrinkage at high temperatures and improvement in gas permeability.
  • the method further comprises the step S3 of forming a bonding layer on at least one side surface of the composite film obtained by the step S2.
  • the method of forming the bonding layer can be referred to conventional art means in the art.
  • step S3 comprises attaching a bonding layer slurry containing a self-crosslinking type pure acrylic emulsion and a self-crosslinking type styrene-acrylic emulsion and/or a copolymer emulsion of vinylidene fluoride and hexafluoropropylene in a step by On at least one side surface of the composite film obtained in S2, and dried to form a bonding layer having a porosity of 40 to 65%.
  • the lithium ion battery separator not only has good high temperature heat shrinkage resistance, but also has higher ionic conductivity and bonding strength, and has more industrial application prospects.
  • the self-crosslinking type pure acrylic emulsion refers to an emulsion obtained by emulsion polymerization of a reactive acrylate monomer.
  • the degree of crosslinking of the acrylate crosslinked polymer in the self-crosslinking type pure acrylic emulsion may be 2 to 30%, alternatively 5 to 20%.
  • the glass transition temperature of the acrylate-based crosslinked polymer in the self-crosslinking type pure acrylic emulsion may be selected from -20 ° C to 60 ° C, and optionally from -12 ° C to 54 ° C.
  • the self-crosslinking type pure acrylic emulsion is a second self-crosslinking type pure acrylic emulsion, a third self-crosslinking type pure acrylic emulsion, or a first self-crosslinking type pure acrylic emulsion and a second a mixture of a self-crosslinking type pure acrylic emulsion and/or a third self-crosslinking type pure acrylic emulsion;
  • the acrylate-based crosslinked polymer in the first self-crosslinking type pure acrylic emulsion contains 70-80% by weight of poly a methyl methacrylate segment, 2 to 10% by weight of a polyethyl acrylate segment, 10 to 20% by weight of a polybutyl acrylate segment, and 2 to 10% by weight of a polyacrylic acid segment
  • the second self The acrylate crosslinked polymer in the crosslinked type pure acrylic emulsion contains 30-40% by weight of polymethyl methacrylate segments, 2-10% by weight of polyethyl acryl
  • the self-crosslinking type styrene-acrylic emulsion refers to a copolymer emulsion obtained by copolymerizing a styrene monomer and a reactive acrylate monomer.
  • the weight ratio of the styrene structural unit to the acrylate structural unit in the styrene-acrylate copolymer may be 0.5-2:1, and optionally 0.67-1.5:1.
  • the styrene-acrylate crosslinked copolymer in the self-crosslinking styrene-acrylic emulsion may have a crosslinking degree of 2 to 30%, alternatively 5 to 20%.
  • the glass transition temperature of the styrene-acrylate crosslinked copolymer in the self-crosslinking type styrene-acrylic emulsion may be selected from -30 ° C to 50 ° C, alternatively from -20 ° C to 50 ° C.
  • the styrene-acrylate crosslinked copolymer in the self-crosslinking type styrene-acrylic emulsion contains 40 to 50% by weight of a polystyrene segment, and 5 to 15% by weight of a polymethyl group.
  • a methyl acrylate segment 2 to 10% by weight of a polyethyl acrylate segment, 30 to 40% by weight of a polybutyl acrylate segment, and 2 to 10% by weight of a polyacrylic acid segment;
  • the cross-linking copolymer has a glass transition temperature of 15 to 30 °C.
  • the glass transition temperature of the vinylidene fluoride-hexafluoropropylene copolymer in the copolymer emulsion of vinylidene fluoride and hexafluoropropylene may be selected from -65 ° C to -40 ° C, and optionally from -60 ° C to -40 ° C.
  • the vinylidene fluoride-hexafluoropropylene copolymer in the copolymer emulsion of vinylidene fluoride and hexafluoropropylene contains 80 to 98% by weight of a polyvinylidene fluoride segment and 2 to 20% by weight.
  • a polyhexafluoropropylene segment optionally comprising 90-96% by weight of a polyvinylidene fluoride segment and 4-10% by weight of a polyhexafluoropropylene segment; vitrification of the vinylidene fluoride-hexafluoropropylene copolymer
  • the transition temperature can be selected from -60 ° C to -40 ° C.
  • the copolymer emulsion of vinylidene fluoride and hexafluoropropylene can be obtained commercially, or can be obtained by various existing methods, or can be obtained by disposing a vinylidene fluoride-hexafluoropropylene copolymer powder into an emulsion.
  • the copolymer emulsion of vinylidene fluoride and hexafluoropropylene is prepared by the following method:
  • the dispersant is a water-soluble polymer dispersant, and includes both an ionic (polyelectrolyte) and a nonionic.
  • the ionic dispersing agent is a polycarboxylic acid type dispersing agent which is homopolymerized by a carboxyl group-containing vinyl monomer (such as acrylic acid, maleic anhydride, etc.) or copolymerized with other monomers, and then neutralized the alcohol ester with a base. Get it.
  • the ionic dispersing agent include, but are not limited to, polyacrylic acid (PAA), polyethyleneimine (PEI), cetyltrimethylammonium bromide (CTAB), polyamide, polyacrylamide (PAM).
  • the nonionic dispersing agent includes polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), fatty alcohol polyoxyethylene ether (JFC), and the like.
  • the weight average molecular weight is from 100 to 500,000 g/mol, optionally from 1,000 to 100,000 g/mol.
  • concentration of the aqueous solution A of the dispersant is from 0.01 to 10% by weight, alternatively from 0.05 to 5% by weight, alternatively from 0.1 to 2% by weight.
  • the dispersant is used in an amount of 0.05 to 10% by weight, alternatively 0.1 to 6% by weight, alternatively 0.1 to 2% by weight, based on the amount of the vinylidene fluoride-hexafluoropropylene copolymer powder used.
  • the ionic dispersant used is an anionic polymer (such as PAM)
  • the ionic dispersant used is a cationic polymer (such as PEI, CTAB)
  • the propylene copolymer powder is effectively protected so that it is stably dispersed in the aqueous phase.
  • the dispersant used is a nonionic polymeric dispersant, the pH of the solution is not adjusted.
  • the tie layer slurry contains a self-crosslinking type pure acrylic emulsion and a self-crosslinking type styrene-acrylic emulsion and does not contain a copolymerized emulsion of vinylidene fluoride and hexafluoropropylene, the self-crosslinking type.
  • the weight ratio of the solid content of the pure acrylic emulsion to the self-crosslinking styrene-acrylic emulsion is 1:0.05-2, optionally 1:1-2; or the bonding layer slurry contains the self-crosslinking pure acrylic emulsion a copolymerization emulsion with vinylidene fluoride and hexafluoropropylene and containing no self-crosslinking styrene-acrylic emulsion, the solid content ratio of the self-crosslinking pure acrylic emulsion to the copolymerized emulsion of vinylidene fluoride and hexafluoropropylene is 1 : 0.3-25, optionally 1:0.4-19; or, the bonding layer slurry comprises a self-crosslinking type pure acrylic emulsion, a self-crosslinking type styrene-acrylic emulsion, a copolymer emulsion of vinylidene fluoride and hexafluor
  • the tie layer slurry comprises a first self-crosslinking type pure acrylic emulsion, a second self-crosslinking type pure acrylic emulsion, and a self-crosslinking type styrene-acrylic emulsion, and
  • the copolymerized emulsion containing vinylidene fluoride and hexafluoropropylene, the first self-crosslinking type pure acrylic emulsion, the second self-crosslinking type pure acrylic emulsion and the self-crosslinking type styrene-acrylic emulsion have a solid content ratio of 5-10: 1:10-13; or,
  • the adhesive layer slurry comprises a first self-crosslinking type pure acrylic emulsion, a second self-crosslinking type pure acrylic emulsion, and a copolymerized emulsion of vinylidene fluoride and hexafluoropropylene, and does not contain a self-crosslinking type styrene-acrylic emulsion.
  • the weight ratio of the first self-crosslinking type pure acrylic emulsion, the second self-crosslinking type pure acrylic emulsion and the copolymerized emulsion of vinylidene fluoride and hexafluoropropylene is 5-15:1:5-12; or
  • the bonding layer slurry comprises a second self-crosslinking type pure acrylic emulsion and a copolymerized emulsion of vinylidene fluoride and hexafluoropropylene and does not contain a self-crosslinking type styrene-acrylic emulsion, and the second self-crosslinking type pure acrylic emulsion
  • the weight ratio of the solid content of the copolymer emulsion of vinylidene fluoride and hexafluoropropylene is 1:5-20; or
  • the adhesive layer slurry comprises a second self-crosslinking type pure acrylic emulsion, a self-crosslinking type styrene-acrylic emulsion, and a copolymerized emulsion of vinylidene fluoride and hexafluoropropylene, the second self-crosslinking type pure acrylic emulsion, self Crosslinked styrene-acrylic emulsion with vinylidene fluoride and hexafluoropropylene
  • the weight ratio of the solid content of the copolymer emulsion is 1:0.5-2:1-5; or
  • the bonding layer slurry comprises a third self-crosslinking type pure acrylic emulsion, a self-crosslinking type styrene-acrylic emulsion, and a copolymerized emulsion of vinylidene fluoride and hexafluoropropylene, and the third self-crosslinking type pure acrylic emulsion, self
  • the weight ratio of the cross-linking type styrene-acrylic emulsion to the copolymerized emulsion of vinylidene fluoride and hexafluoropropylene is 1:0.5-2:1-5; or
  • the bonding layer slurry comprises a first self-crosslinking type pure acrylic emulsion, a second self-crosslinking type pure acrylic emulsion, a self-crosslinking type styrene-acrylic emulsion, and a copolymer emulsion of vinylidene fluoride and hexafluoropropylene,
  • the weight ratio of the cross-linking type pure acrylic emulsion, the second self-crosslinking type pure acrylic emulsion, the self-crosslinking type styrene-acrylic emulsion and the copolymerized emulsion of vinylidene fluoride and hexafluoropropylene is 10-15:1:0.5- 2:5-10;
  • the acrylate crosslinked polymer in the first self-crosslinking type pure acrylic emulsion contains 70-80% by weight of polymethyl methacrylate segment, 2-10% by weight of polyethyl acrylate segment, 10 -20% by weight of polybutyl acrylate segment and 2-10% by weight of polyacrylic acid segment
  • the acrylate crosslinked polymer in the second self-crosslinking pure acrylic emulsion contains 30-40% by weight Polymethyl methacrylate segment, 2-10% by weight of polyethyl acrylate segment, 50-60% by weight of polybutyl acrylate segment and 2-10% by weight of polyacrylic acid segment
  • the acrylate crosslinked polymer in the self-crosslinking type pure acrylic emulsion contains 50-80% by weight of polymethyl methacrylate segment, 2-10% by weight of polyethyl acrylate segment, 15-40% by weight Polybutyl acrylate segment and 2-10% by weight of polyacrylic acid segment
  • the tie layer slurry further contains at least one of a copolymer emulsion of acrylonitrile and acrylate, a chloropropene emulsion, and a styrene-butadiene latex.
  • the copolymer layer slurry further contains a copolymer emulsion of acrylonitrile and acrylate, it is advantageous to improve the ionic conductivity of the battery separator inside the battery; when the bonding layer slurry further contains a chloropropene emulsion and/or Or styrene-butadiene latex, it is beneficial to reduce the liquid absorption rate of the battery separator, so that the liquid absorption rate is not too high, because the liquid absorption rate is too high, the internal and negative electrodes of the battery lack electrolyte and crack the battery performance.
  • the binder layer slurry further contains a copolymer emulsion of acrylonitrile and acrylate
  • the weight ratio of the solid content of the copolymer emulsion of acrylonitrile and acrylate to the solid content of the self-crosslinking type pure acrylic emulsion is optional. 0.05-2:1, optional 0.08-1.85:1.
  • the binder layer slurry further contains a chloropropene emulsion
  • the weight ratio of the solid content of the chloropropene emulsion to the solid content of the self-crosslinking type pure acrylic emulsion may be 0.15-7:1, optionally 0.2-6:1.
  • the weight ratio of the solid content of the styrene-butadiene latex to the solid content of the self-crosslinking type pure acrylic emulsion may be 0.05-2:1, optionally 0.08-1.85:1.
  • the bonding layer slurry may have a total solid content of 0.5-25% by weight, alternatively 1-20% by weight, optionally 1-10% by weight.
  • the method of attaching may alternatively adopt a spray coating method and/or a screen printing method to form a porous film having the above porosity directly by a discontinuous coating by a spray coating method and/or a screen printing method, so that a porous film can be prepared (not Continuous) self-crosslinking polymer coating without the need for a phase separation process.
  • the spray temperature can be selected from 30 to 80 ° C, optionally from 40 to 75 ° C.
  • the screen printing temperature can be selected from 30 to 80 ° C, optionally from 40 to 75 ° C.
  • the amount of the bonding layer slurry may be selected such that the formed bonding layer has a single-sided thickness of 0.1 to 1 ⁇ m, alternatively 0.2 to 0.6 ⁇ m.
  • the present disclosure also provides a lithium ion battery separator prepared by the above method.
  • the present disclosure also provides a lithium ion battery including a positive electrode, a negative electrode, an electrolyte, and a separator, wherein the separator is the above-described ceramic separator.
  • the electrolyte is well known to those skilled in the art and typically consists of an electrolyte lithium salt and an organic solvent.
  • the lithium salt of the electrolyte is a dissociable lithium salt, for example, at least one selected from the group consisting of lithium hexafluorophosphate (LiPF 6 ), lithium perchlorate (LiClO 4 ), lithium tetrafluoroborate (LiBF 4 ), and the like, an organic solvent. It may be selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), vinylene carbonate (VC), and the like. At least one of them.
  • the concentration of the electrolyte lithium salt in the electrolyte is 0.8-1.5 mol/L.
  • the positive electrode is prepared by coating a positive electrode material for a lithium ion battery, a conductive agent, and a binder onto an aluminum foil.
  • the positive electrode material used includes any positive electrode material usable for a lithium ion battery, for example, lithium cobalt oxide (LiCoO 2 ), lithium nickel oxide (LiNiO 2 ), lithium manganese oxide (LiMn 2 O 4 ), lithium iron phosphate (LiFePO 4 ). At least one of the others.
  • the negative electrode is prepared by coating a negative electrode material for a lithium ion battery, a conductive agent, and a binder onto a copper foil.
  • the negative electrode material used includes any negative electrode material usable for a lithium ion battery, for example, at least one of graphite, soft carbon, hard carbon, and the like.
  • the main improvement of the lithium ion battery provided by the present disclosure is that a new lithium ion battery separator is used, and the arrangement manner (connection manner) of the positive electrode, the negative electrode, the battery separator and the electrolyte can be the same as the prior art, Those skilled in the art will be aware of this and will not be described herein.
  • the method for preparing a lithium ion battery includes sequentially laminating or winding a positive electrode, a separator, and a negative electrode into a pole core. Then, an electrolyte is injected into the pole core and sealed, wherein the separator is the lithium ion battery separator described above.
  • polybutyl acrylate segment accounts for 15% by weight
  • polymethyl methacrylate segment accounts for 75% by weight
  • polyethyl acrylate segment accounts for 5% by weight
  • polyacrylic acid segment accounts for 5% by weight
  • vitrification Transformation temperature Tg 54°C, solid content 50% by weight, Shanghai Aigao Chemical Co., Ltd.;
  • polystyrene segment accounts for 45% by weight
  • polybutyl acrylate segment accounts for 35% by weight
  • polymethyl methacrylate segment accounts for 10% by weight
  • polyethyl acrylate segment accounts for 5% by weight
  • polyacrylic acid chain The segment accounts for 5% by weight
  • the solid content is 50% by weight.
  • Polyvinylidene fluoride segment accounts for 95% by weight
  • polyhexafluoropropylene segment accounts for 5% by weight
  • weight average molecular weight Mw 450000
  • glass transition temperature is -55 ° C
  • solid content is 30% by weight
  • Ceramic layer gas permeability (Gurley value) test The ceramic diaphragm was cut into a ceramic diaphragm sample having an area of 6.45 cm 2 , and a Gurley value tester GURLEY-4110, pressure (water column height) 12.39 cm was used to measure 100 ml of gas. The time (s/100 ml) required for (air) to pass through the aforementioned ceramic diaphragm sample, the smaller the value, the better the gas permeability.
  • the preparation of each process includes only a single a ceramic diaphragm which does not include a heat-resistant layer and a bonding layer, and a sample of 40 mm ⁇ 100 mm is cut therefrom, and both sides of the ceramic diaphragm are fixed on the fixing jig and the movable jig by tape, and the 180 ° C reverse stretching is performed.
  • the ceramic layer and the substrate film are peeled off, the greater the required tensile force, the higher the peel strength of the ceramic separator, indicating that the bond strength is higher.
  • Heat shrinkage test The lithium ion battery separator was cut into 6 cm ⁇ 6 cm samples, placed in an oven, and baked at 120 ° C, 140 ° C, 160 ° C, 180 ° C for 1 h, measuring the length and width of the sample, And calculate the heat shrinkage rate according to the following formula:
  • Heat shrinkage rate (1 - length of sample after heat shrinkage / 6) ⁇ 100%;
  • M 0 is the mass (mg) of the dry film
  • M is the mass (mg) after soaking for 2 hours in n-butanol
  • r is the radius (mm) of the film
  • d is the thickness ( ⁇ m) of the film.
  • Adhesive layer liquid absorption rate test The porous self-crosslinking polymer films Sb1-Sb13 obtained in Examples 11-23 were cut into discs having a diameter of 17 mm, dried, and weighed into a good mass and then immersed in an electrolyte solution ( The electrolyte contained 32.5% by weight of EC (ethylene carbonate), 32.5% by weight of EMC (ethyl methyl carbonate), 32.5% by weight of DMC (dimethyl carbonate), and 2.5% by weight of VC (carbonic acid). 24 hours in the vinyl ester) and 1 mol/L LiPF 6 (lithium hexafluorophosphate), then take out the liquid on the surface of the membrane with a filter paper and weigh the mass at this time. The operation is carried out in an argon-filled glove box, then follow the following The formula calculates the liquid absorption rate:
  • Liquid absorption rate% (Wi-W)/W ⁇ 100%
  • W is the mass of the dry film (g); Wi is the mass (g) of the dry film after soaking for 24 hours in the electrolyte.
  • Example 1 (Porous ion film (PE base film) - heat-resistant layer two-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Polyetherimide (PEI, commercially available from SABIC Innovative Plastics (Shanghai) Co., Ltd., melting point of 370-410 ° C, the same below) and Al 2 O 3 particles (average particle size of 200 nm, the same below)
  • the weight ratio of 10:1 i.e., 100:10 was added to N,N-dimethylpyrrolidone (NMP), followed by thorough magnetic stirring under a water bath at 70 ° C to form a spinning solution having a concentration of 15% by weight.
  • a surface of one side of a PE base film (available from SK Corporation of Japan under the designation BD1201, thickness 11 ⁇ m, the same below) was wrapped on a drum (collection device), and a needle was electrospun on the surface of the PE base film.
  • the above spinning solution was subjected to electrospinning. Adjust the electrospinning parameters as follows: receiving distance is 12cm, temperature is 25°C, humidity is 50%, needle inner diameter is 0.46mm, needle moving speed is 6.6mm/sec, voltage is 10kV, flow rate is 0.3mL/h, drum speed It is 2000 rpm.
  • the heat-resistant layer has a fiber network structure in which the fiber thickness is relatively uniform, and the phenomenon of agglomeration of the beads and the polymer does not occur, and the fibers are intertwined with each other to form a large number of Pores, and part of the fiber surface can clearly see the presence of inorganic particles, and the inorganic particles do not agglomerate.
  • the diameter of the fiber in the SEM image was measured by TEM Macrography software, and the data was recorded.
  • the final calculated fiber diameter was 300 nm
  • the surface density of the heat-resistant layer was 3.3 g/m 2
  • the porosity was 85%.
  • the lithium ion battery separator has a transverse tensile strength and a longitudinal tensile strength of 145 MPa and 148 MPa, a needle punching strength of 0.530 kgf, and an ionic conductivity of 7.8 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were 0%, 0%, 3.8%, and 6.2%, respectively.
  • the longitudinal heat shrinkage rates were: 0%, 0%, 4%, 6.6%.
  • This comparative example is used to illustrate a reference lithium ion battery separator and a method of preparing the same.
  • the PE base film of Example 1 itself was used as a lithium ion battery separator of the present comparative example.
  • the lithium-ion battery separator was tested to have a transverse tensile strength and a longitudinal tensile strength of 150 MPa and 152 MPa, a needle punching strength of 0.501 kgf, and an ionic conductivity of 7.9 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C, and 180 ° C for 1 h, respectively. The results showed that the transverse and longitudinal heat shrinkage rates at 120 ° C were 7% and 75.2%, respectively. Above 140 ° C (including 140 ° C, 160 ° C, 180 ° C), melting into a mass, shrinkage of more than 95%.
  • Example 2 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • the viscosity of the aqueous solution is 2500-3000 mPa ⁇ s, which is purchased from Xinxiang City and Lilida Power Materials Co., Ltd. under the designation BTT-3000).
  • the mixture is uniformly mixed with water, so that the solid content of Al 2 O 3 is 30% by weight.
  • the mixture was stirred at 6000 rpm for 1.5 hours, after which 0.02 kg of 3-glycidoxypropyltrimethoxysilane was added and stirring was continued for 1.5 hours, followed by the addition of 0.1 kg of a polyacrylate binder (the crosslinking monomer was N- Methylol acrylamide and its content was 4% by weight, glass transition temperature was -20 ° C), and stirred at 3000 rpm for 1.5 hours, followed by the addition of 0.08 kg of sodium dodecylbenzene sulfonate, followed by stirring at 3000 rpm 0.5 After hours, a slurry of the ceramic layer was obtained.
  • a polyacrylate binder the crosslinking monomer was N- Methylol acrylamide and its content was 4% by weight, glass transition temperature was -20 ° C
  • the above ceramic layer slurry was coated on both sides of a 11 ⁇ m-thick PE base film (available from SK Corporation, Japan under the designation BD1201, the same below), and dried to obtain a thickness of 1 ⁇ m on both side surfaces of the base film.
  • the ceramic layer is obtained, and the ceramic separator C1 is obtained.
  • the ceramic layers on both sides of the ceramic separator C1 have an areal density of 2.11 mg/cm 2 at a thickness of 1 ⁇ m, a gas permeability of 202 s/100 ml, and a peel strength of 5.4 N.
  • the thermal stability at 120 ° C is A
  • the thermal stability at 160 ° C is A.
  • the lithium ion battery separator was baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 2.3%, 4%, and the longitudinal heat shrinkage rates were: 0%, 0%, 2.4%, 5%.
  • This comparative example is used to illustrate a reference lithium ion battery separator and a method of preparing the same.
  • a lithium ion battery separator was prepared in the same manner as in Example 2 except that the ceramic layer slurry was used in an amount such that the thickness of the ceramic layer was 4 ⁇ m, and the step of forming the heat-resistant layer was not included, and a lithium ion battery separator was obtained.
  • the lithium-ion battery separator was tested to have a transverse tensile strength and a longitudinal tensile strength of 132 MPa and 143 MPa, a needle punching strength of 0.512 kgf, and an ionic conductivity of 6.9 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C, and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were 0.3%, 1%, 6.5%, and 86%, respectively.
  • the longitudinal heat shrinkage rates were : 0.5%, 1.5%, 5.5%, 82.2%.
  • This comparative example is used to illustrate a reference lithium ion battery separator and a method of preparing the same.
  • a lithium ion battery separator was produced in the same manner as in Example 2 except that the heat-resistant layer was formed by a coating method to obtain a lithium ion battery separator in which the heat-resistant layer did not have a porous structure.
  • the lithium-ion battery separator was tested to have a transverse tensile strength and a longitudinal tensile strength of 125 MPa and 130 MPa, a needle punching strength of 0.53 kgf, and an ionic conductivity of 0.05 mS/cm.
  • the lithium ion battery separator was baked at 120 ° C, 140 ° C, 160 ° C, and 180 ° C for 1 h, respectively, and the transverse heat shrinkage rates were: 0%, 0%, 0.2%, 2%, respectively, and the longitudinal heat shrinkage rates were respectively It is: 0%, 0%, 1.5%, 2.4%.
  • Example 3 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Electrospinning was carried out in the same manner as in Example 2 to obtain a lithium ion battery separator F3 having a heat-resistant layer (single-sided thickness: 3 ⁇ m).
  • the average diameter of the fibers in the heat-resistant layer was 258 nm, and the surface density of the heat-resistant layer was 3.2. g/m 2 , porosity is 84%.
  • the lithium ion battery separator has a transverse tensile strength and a longitudinal tensile strength of 122 MPa and 126 MPa, a needle punching strength of 0.530 kgf, and an ionic conductivity of 7.7 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 3.2%, 4.5%
  • the longitudinal heat shrinkage rates were: 0%, 0%, 3.5%, 4.8%.
  • Example 4 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Electrospinning was carried out in the same manner as in Example 2 to obtain a lithium ion battery separator F4 having a heat-resistant layer (thickness: 3 ⁇ m).
  • the average diameter of the fibers in the heat-resistant layer was 420 nm, and the areal density of the heat-resistant layer was 4.1 g/ m 2 , the porosity was 87%.
  • the lithium ion battery separator has a transverse tensile strength and a longitudinal tensile strength of 118 MPa and 122 MPa, a needle punching strength of 0.530 kgf, and an ionic conductivity of 6.9 mS/cm.
  • the lithium ion battery separator was baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 1.2%, 4%, and the longitudinal heat shrinkage rates were: 0%, 0%, 2.3%, 4.5%.
  • Example 5 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Electrospinning was carried out in the same manner as in Example 2 to obtain a lithium ion battery separator F5 having a heat-resistant layer (thickness: 3 ⁇ m).
  • the average diameter of the fibers in the heat-resistant layer was 420 nm, and the areal density of the heat-resistant layer was 4.1 g/ m 2 , the porosity was 87%.
  • the lithium ion battery separator has a transverse tensile strength and a longitudinal tensile strength of 114 MPa and 118 MPa, a needle punching strength of 0.530 kgf, and an ionic conductivity of 6.5 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were 0%, 0%, 1.2%, and 3.5%, respectively.
  • the longitudinal heat shrinkage rates were: 0%, 0%, 2.3%, 4.2%.
  • Example 6 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • the above ceramic layer slurry was coated on one side surface of a 11 ⁇ m-thick PE base film, and dried to obtain a ceramic layer having a thickness of 2 ⁇ m on one side surface of the base film to obtain a ceramic separator C2, and the ceramic separator C2 was examined.
  • the ceramic layer had an areal density of 2.02 mg/cm 2 at a thickness of 1 ⁇ m, a gas permeability of 198 s/100 ml, a peel strength of 5.6 N, a thermal stability at 120 ° C of A, and a thermal stability at 160 ° C of A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C2 in the same manner as in Example 2 to obtain a lithium ion battery separator F6 having a heat-resistant layer formed therein.
  • the average diameter of the fibers in the heat-resistant layer was 320 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator had a transverse tensile strength and a longitudinal tensile strength of 123 MPa and 129 MPa, a needle punching strength of 0.53 kgf, and an ionic conductivity of 7.7 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 3.3%, 5%, and the longitudinal heat shrinkage rates were: 0%, 0%, 3.8%, 6.1%.
  • Example 7 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • titanium dioxide particles (average particle size of 500 nm), 0.008 kg of sodium polyacrylate (number average molecular weight of 9000, purchased from Guangzhou Yuanchang Trading Co., Ltd.), 0.03 kg of sodium carboxymethyl nanocellulose (1% by weight aqueous solution viscosity) 2500-3000mPa ⁇ s, purchased from Xinxiang City and Lalida Power Materials Co., Ltd., grade BTT-3000) and water mixed evenly, so that the solid content of titanium dioxide is 25% by weight of the mixture, the mixture is at 4000 rpm Stir at /min for 1.5 hours, then add 0.024 kg of 3-glycidylpropyltrimethoxysilane and continue to stir for 1.5 hours, then add 0.08 kg of polyacrylate binder (crosslinking monomer hydroxymethyl acrylate and its content) 5 wt%, glass transition temperature was 0 ° C), and stirred at 3000 rpm for 1.5 hours, followed by the addition of 0.08 kg of sodium dodecylbenz
  • the above ceramic layer slurry was coated on one side surface of a 11 ⁇ m thick PE base film, and dried to obtain a ceramic layer having a thickness of 3.5 ⁇ m on one side surface of the base film to obtain a ceramic separator C2, which was tested and ceramic.
  • the ceramic layer of the separator C2 has an areal density of 2.05 mg/cm 2 at a thickness of 1 ⁇ m, a gas permeability of 200 s /100 ml, a peel strength of 5.7 N, a thermal stability at 120 ° C of A, and a thermal stability at 160 ° C. A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C3 in the same manner as in Example 2 to obtain a lithium ion battery separator F7 having a heat-resistant layer.
  • the average diameter of the fibers in the heat-resistant layer was 340 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator had a transverse tensile strength and a longitudinal tensile strength of 117 MPa and 121 MPa, a needle punching strength of 0.53 kgf, and an ionic conductivity of 7.6 mS/cm.
  • the lithium ion battery separator was baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 2.5%, 4.2%, and the longitudinal heat shrinkage rates were: 0%, 0%, 2.5%, 5.5%.
  • Example 8 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Example 2 The method of Example 2 was carried out except that the amount of the polyacrylate binder used in preparing the ceramic layer slurry was 0.06 kg, and the content of the crosslinking monomer in the polyacrylate binder was 7% by weight to obtain a ceramic.
  • Diaphragm C4 after testing, the ceramic layers on both sides of the ceramic diaphragm C4 have an areal density of 1.95 mg/cm 2 at a thickness of 1 ⁇ m, a gas permeability of 208 s/100 ml, a peel strength of 4.3 N, and thermal stability at 120 ° C. The properties are all A, and the thermal stability at 160 ° C is A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C4 in the same manner as in Example 2 to obtain a lithium ion battery separator F8 having a heat-resistant layer.
  • the average diameter of the fibers in the heat-resistant layer was 340 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator had a transverse tensile strength and a longitudinal tensile strength of 121 MPa and 125 MPa, a needle punching strength of 0.53 kgf, and an ionic conductivity of 7.5 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 2.8%, 4.2%, respectively.
  • the longitudinal heat shrinkage rates were: 0%, 0%, 2.6%, 5.2%.
  • Example 9 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • Example 2 The method of Example 2 was carried out except that the amount of the polyacrylate binder used in preparing the ceramic layer slurry was 0.12 kg, and the content of the crosslinking monomer in the polyacrylate binder was 5% by weight, and was not added. 3-Glycidyloxypropyltrimethoxysilane, the ceramic separator C5 was obtained. After testing, the ceramic layers on both sides of the ceramic separator C5 had an areal density of 1.91 mg/cm 2 at a thickness of 1 ⁇ m, and the gas permeability was 212 s. /100ml, the peel strength is 4.5N, the thermal stability at 120 ° C is A, and the thermal stability at 160 ° C is A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C5 in the same manner as in Example 2 to obtain a lithium ion battery separator F9 having a heat-resistant layer.
  • the average diameter of the fibers in the heat-resistant layer was 340 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator had a transverse tensile strength and a longitudinal tensile strength of 119 MPa and 125 MPa, a needle punching strength of 0.53 kgf, and an ionic conductivity of 7.4 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 3.6%, 5.7%, respectively.
  • the longitudinal heat shrinkage rates were: 0%, 0%, 3.1%, 5.9%.
  • Example 10 heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer three-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Example 2 The method of Example 2 was carried out, except that the amount of the polyacrylate binder used in preparing the ceramic layer slurry was 0.08 kg, and the content of the crosslinking monomer in the polyacrylate binder was 2% by weight to obtain a ceramic.
  • Diaphragm C6 after testing, the ceramic layers on both sides of the ceramic separator C6 have an areal density of 2.00 mg/cm 2 at a thickness of 1 ⁇ m, a gas permeability of 207 s/100 ml, a peel strength of 4.6 N, and heat stability at 120 ° C. The properties are all A, and the thermal stability at 160 ° C is A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C6 in the same manner as in Example 2 to obtain a lithium ion battery separator F10 having a heat-resistant layer formed therein.
  • the average diameter of the fibers in the heat-resistant layer was 340 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator has a transverse tensile strength and a longitudinal tensile strength of 120 MPa and 122 MPa, a needle punching strength of 0.54 kgf, and an ionic conductivity of 7.4 mS/cm.
  • the lithium ion battery separator was baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 3%, 4.5%
  • the longitudinal heat shrinkage rates were: 0%, 0%, 2.8%, 5.8%.
  • Embodiment 11 Porous base film (ceramic diaphragm)-heat-resistant layer two-layer structure lithium ion battery separator, wherein the ceramic layer is a non-optional ceramic layer)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Example 2 The method of Example 2 was carried out except that the average particle diameter of the aluminum oxide was 700 nm, and the ceramic separator C7 was obtained. After testing, the ceramic layers on both sides of the ceramic separator C7 had an areal density of 2.11 mg at a thickness of 1 ⁇ m. /cm 2 , gas permeability is 205s/100ml, peel strength is 4.7N, thermal stability at 120°C is A, and thermal stability at 160°C is A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C7 in the same manner as in Example 2 to obtain a lithium ion battery separator F11 having a heat-resistant layer formed therein.
  • the average diameter of the fibers in the heat-resistant layer was 340 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator had a transverse tensile strength and a longitudinal tensile strength of 121 MPa and 125 MPa, a needle punching strength of 0.53 kgf, and an ionic conductivity of 7.1 mS/cm.
  • the lithium ion battery separators were baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were: 0%, 0%, 3%, 6%
  • the longitudinal heat shrinkage rates were: 0%, 0%, 3.5%, 6.5%.
  • Embodiment 12 Porous base film (ceramic diaphragm)-heat-resistant layer two-layer structure lithium ion battery separator, wherein the ceramic layer is a non-optional ceramic layer)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • Example 2 The method of Example 2 was carried out except that the average particle diameter of the aluminum oxide was 250 nm, and the ceramic separator C8 was obtained.
  • the surface density of the ceramic layers on both sides of the ceramic separator C8 was 1.91 mg/cm 2 .
  • the gas permeability was 208 s/100 ml, the peel strength was 4.8 N, the thermal stability at 120 ° C was A, and the thermal stability at 160 ° C was A.
  • Electrospinning was performed on the surface of the ceramic layer of the ceramic separator C8 in the same manner as in Example 2 to obtain a lithium ion battery separator F11 having a heat-resistant layer formed therein.
  • the average diameter of the fibers in the heat-resistant layer was 340 nm, and the areal density of the heat-resistant layer was obtained. It was 3.3 g/m 2 and the porosity was 82%.
  • the lithium ion battery separator has a transverse tensile strength and a longitudinal tensile strength of 120 MPa and 125 MPa, a needle punching strength of 0.52 kgf, and an ionic conductivity of 6.9 mS/cm.
  • the lithium ion battery separator was baked at 120 ° C, 140 ° C, 160 ° C and 180 ° C for 1 h, respectively.
  • the transverse heat shrinkage rates were 0%, 0%, 3.2%, and 6.2%, respectively.
  • the longitudinal heat shrinkage rates were: 0%, 0%, 3.8%, 6.8%.
  • Example 13 bonding layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1040), self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) and self-crosslinking type styrene-acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade S601) is mixed at a mass ratio of 9:1:10, and an appropriate amount of water is added, and uniformly stirred to form a tie layer slurry having a total solid content of 1% by weight.
  • the above-mentioned adhesive layer slurry was sprayed onto both side surfaces of the above composite film and one side surface of the PE base film by a spraying method (temperature: 40 ° C), and then dried at 50 ° C to obtain a porous self.
  • a cross-linked polymer film (bonding layer) of a lithium ion battery separator Sa1 and a porous self-crosslinking polymer film Sb1 on a PE base film wherein the porous self-crosslinking polymer film has a single face density of 0.1 g/m 2 , the thickness of one side is 0.2 ⁇ m, the porosity is 62% and the liquid absorption rate is 263%, and the ionic conductivity of the lithium ion battery separator Sa1 is 8.28mS/cm.
  • Example 14 (tie layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Copolymerization emulsion of vinylidene fluoride and hexafluoropropylene (Arkema, grade 10278), self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) and self-crosslinking styrene-acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade S601) is mixed at a mass ratio of 12:4:4, and added with an appropriate amount of water, and uniformly mixed to form a tie layer slurry having a total solid content of 5% by weight.
  • the above-mentioned adhesive layer paste was printed on both side surfaces of the above composite film and one side surface of the PE base film by screen printing (temperature: 75 ° C), and then dried at 50 ° C, respectively, including a porous self-crosslinking polymer film of a lithium ion battery separator Sa2 and a porous self-crosslinking polymer film Sb2 on a PE base film, wherein the porous self-crosslinking polymer film has a single face density of 0.2 g/m 2 , a single The surface thickness was 0.4 ⁇ m, the porosity was 48%, and the liquid absorption rate was 192%.
  • the ion conductivity of the lithium ion battery separator Sa2 was 7.4 mS/cm.
  • Example 15 bonding layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1040), copolymerized emulsion of vinylidene fluoride and hexafluoropropylene (Arkema, grade 10278), self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) and self-crosslinking styrene-acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade S601) are mixed at a solid content of 12:6:1:1, and added with appropriate amount of water. The mixture was uniformly mixed to form a tie layer slurry having a total solid content of 10% by weight.
  • the above-mentioned adhesive layer slurry was sprayed onto both side surfaces of the composite film and one side surface of the PE base film by a spraying method (temperature: 58 ° C), and then dried at 50 ° C to obtain a porous self.
  • the ion conductivity of the lithium ion battery separator Sa3 was 7 mS/cm.
  • Example 16 (tie layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1040), copolymerized emulsion of vinylidene fluoride and hexafluoropropylene (Arkema, grade 10278) and self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) is mixed at a mass ratio of solid content of 12.7:6.3:1, and an appropriate amount of water is added, and uniformly stirred to form a tie layer slurry having a total solid content of 1% by weight.
  • the above-mentioned adhesive layer paste was printed on both side surfaces of the above composite film and one side surface of the PE base film by screen printing (temperature: 40 ° C), and then dried at 50 ° C, respectively, including a porous self-crosslinking polymer film of a lithium ion battery separator Sa4 and a porous self-crosslinking polymer film Sb4 on a PE base film, wherein the porous self-crosslinking polymer film has a single face density of 0.1 g/m 2 , a single The surface thickness was 0.2 ⁇ m, the porosity was 53%, and the liquid absorption rate was 317%.
  • the ionic conductivity of the lithium ion battery separator Sa4 was 7.46 mS/cm.
  • Example 17 bonding layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1040), self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) and self-crosslinking type styrene-acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade S601) was mixed at a mass ratio of 6:1:13, and an appropriate amount of water was added thereto, and uniformly stirred to form a binder layer slurry having a total solid content of 5% by weight.
  • the above-mentioned adhesive layer slurry was sprayed onto both side surfaces of the above composite film and one side surface of the PE base film by a spraying method (temperature: 75 ° C), and then dried at 50 ° C to obtain a porous self.
  • the ionic conductivity of the lithium ion battery separator Sa5 was 7.15 mS/cm.
  • Example 18 bonding layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Self-crosslinking type pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1040), vinylidene fluoride and hexafluoropropylene Copolymer emulsion (Arkema, grade 10278) and self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) are mixed at a mass ratio of 11.4:7.6:1, and added with appropriate amount of water, stirring The adhesive layer slurry having a total solid content of 10% by weight was uniformly formed.
  • the above-mentioned adhesive layer paste was printed on both side surfaces of the above composite film and one side surface of the PE base film by screen printing (temperature: 75 ° C), and then dried at 50 ° C, respectively, including a porous self-crosslinking polymer film of a lithium ion battery separator Sa6 and a porous self-crosslinking polymer film Sb6 on a PE base film, wherein the porous self-crosslinking polymer film has a single face density of 0.3 g/m 2 , a single The surface thickness was 0.6 ⁇ m, the porosity was 55%, and the liquid absorption rate was 287%.
  • the ion conductivity of the lithium ion battery separator Sa6 was 7.81 mS/cm.
  • Example 19 bonding layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer four-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1040), copolymerized emulsion of vinylidene fluoride and hexafluoropropylene (Arkema, grade 10278) and self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) is mixed at a mass ratio of 9.5:9.5:1, and an appropriate amount of water is added, and uniformly stirred to form a tie layer slurry having a total solid content of 1% by weight.
  • the above-mentioned adhesive layer slurry was sprayed onto both side surfaces of the above composite film and one side surface of the PE base film by a spraying method (temperature: 40 ° C), and then dried at 50 ° C to obtain a porous self.
  • the ionic conductivity of the lithium ion battery separator Sa7 was 7.95 mS/cm.
  • Example 20 (tie layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Copolymerization emulsion of vinylidene fluoride and hexafluoropropylene (Arkema, grade 10278) and self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) were mixed at a mass ratio of 19:1 And adding an appropriate amount of water, and uniformly stirring to form a bonding layer slurry having a total solid content of 5% by weight.
  • the above-mentioned adhesive layer paste was printed on both side surfaces of the above composite film and one side surface of the PE base film by screen printing (temperature: 75 ° C), and then dried at 50 ° C, respectively, including a porous self-crosslinking polymer film of a lithium ion battery separator Sa8 and a porous self-crosslinking polymer film Sb8 on a PE base film, wherein the porous self-crosslinking polymer film has a single face density of 0.2 g/m 2 , a single The surface thickness was 0.3 ⁇ m, the porosity was 53%, and the liquid absorption rate was 76%.
  • the ion conductivity of the lithium ion battery separator Sa8 was 7.58 mS/cm.
  • Example 21 (tie layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • Copolymerization emulsion of vinylidene fluoride and hexafluoropropylene (Arkema, grade 10278) and self-crosslinking pure acrylic emulsion (Shanghai Ai Gao Chemical Co., Ltd., grade 1005) were mixed at a mass ratio of 18:2. And adding an appropriate amount of water, and uniformly mixing to form a bonding layer slurry having a total solid content of 10% by weight.
  • the above-mentioned adhesive layer slurry was sprayed onto both side surfaces of the composite film and one side surface of the PE base film by a spraying method (temperature: 58 ° C), and then dried at 50 ° C to obtain a porous self.
  • the ionic conductivity of the lithium ion battery separator Sa9 was 7.28 mS/cm.
  • Example 22 bonding layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • the adhesive layer slurry was prepared according to the method of Example 13, except that the adhesive layer slurry further contained a copolymer emulsion of acrylonitrile and acrylate (Shanghai Ai Gao Chemical Co., Ltd., grade A1030, polyacrylonitrile chain).
  • the segment accounts for 15% by weight
  • the polybutyl acrylate segment accounts for 30% by weight
  • the polymethyl methacrylate segment accounts for 45% by weight
  • the polyethyl acrylate segment accounts for 5% by weight
  • the polyacrylic acid segment accounts for 5% by weight.
  • the glass transition temperature Tg 28 ° C
  • the solid content was 50% by weight
  • the weight ratio of the solid content of A1030 to the total solid content of 1040 and 1005 was 1:1.
  • the bonding layer slurry was formed into a bonding layer according to the method of Example 13, to obtain a lithium ion battery separator Sa10 comprising a porous self-crosslinking polymer film and a porous self-crosslinking polymer film Sb10 on the PE base film, wherein
  • the surface porous self-crosslinking polymer coatings have an areal density of 0.1 g/m 2 , a thickness of 0.2 ⁇ m, a porosity of 48% and a liquid absorption rate of 293%.
  • the ionic conductivity of the lithium ion battery separator Sa10 It is 7.68 mS/cm.
  • Example 23 bonding layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • the adhesive layer slurry was prepared according to the method of Example 13, except that the adhesive layer slurry further contained a copolymer emulsion of acrylonitrile and acrylate (Shanghai Ai Gao Chemical Co., Ltd., grade A1030, polyacrylonitrile chain).
  • the segment accounts for 15% by weight
  • the polybutyl acrylate segment accounts for 30% by weight
  • the polymethyl methacrylate segment accounts for 45% by weight
  • the polyethyl acrylate segment accounts for 5% by weight
  • the polyacrylic acid segment accounts for 5% by weight.
  • the glass transition temperature Tg 28 ° C
  • the solid content was 50% by weight
  • the weight ratio of the solid content of A1030 to the total solid content of 1040 and 1005 was 1:1.
  • the bonding layer slurry was formed into a bonding layer according to the method of Example 13, to obtain a lithium ion battery separator Sa11 including a porous self-crosslinking polymer film and a porous self-crosslinking polymer film Sb11 on the PE base film, wherein
  • the surface porous self-crosslinking polymer coating has an areal density of 0.1 g/m 2 , a thickness of 0.2 ⁇ m, a porosity of 50% and a liquid absorption rate of 214%, and an ion conductivity of the lithium ion battery separator Sa11. It is 7.18 mS/cm.
  • Example 24 bonding layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • the adhesive layer slurry was prepared according to the method of Example 13, except that the adhesive layer slurry further contained a copolymer emulsion of acrylonitrile and acrylate (Shanghai Ai Gao Chemical Co., Ltd., grade A1030, polyacrylonitrile chain).
  • the segment accounts for 15% by weight
  • the polybutyl acrylate segment accounts for 30% by weight
  • the polymethyl methacrylate segment accounts for 45% by weight
  • the polyethyl acrylate segment accounts for 5% by weight
  • the polyacrylic acid segment accounts for 5% by weight.
  • the glass transition temperature Tg 28 ° C
  • the solid content was 50% by weight
  • the weight ratio of the solid content of A1030 to the total solid content of 1040 and 1005 was 1:1.
  • the bonding layer slurry was formed into a bonding layer according to the method of Example 13, to obtain a lithium ion battery separator Sa12 comprising a porous self-crosslinking polymer film and a porous self-crosslinking polymer film Sb12 on the PE base film, wherein
  • the surface porous self-crosslinking polymer coating has an areal density of 0.1 g/m 2 , a thickness of 0.2 ⁇ m, a porosity of 46% and a liquid absorption rate of 182%.
  • the ionic conductivity of the lithium ion battery separator Sa12 It is 7.27 mS/cm.
  • Example 25 bonding layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is for explaining a lithium ion battery separator provided by the present disclosure and a method of producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • a tie layer slurry was prepared in the same manner as in Example 14 except that the self-crosslinking type pure acrylic emulsion 1005 was replaced with the same part by weight of the self-crosslinking type pure acrylic emulsion 1020.
  • the bonding layer slurry was formed into a bonding layer according to the method of Example 12 to obtain a lithium ion battery separator Sa13 including a porous self-crosslinking polymer film and a porous self-crosslinking polymer film Sb13 on the PE base film, wherein
  • the surface porous self-crosslinking polymer coating has an areal density of 0.2 g/m 2 , a thickness of 0.4 ⁇ m, a porosity of 47% and a liquid absorption rate of 160%, and an ion conductivity of the lithium ion battery separator Sa13. It is 6.98 mS/cm.
  • the bonding layer was subjected to a comparative example (tie layer-heat-resistant layer-porous base film (ceramic diaphragm)-heat-resistant layer-bonding layer five-layer structure lithium ion battery separator)
  • This embodiment is a comparative example for explaining a polymer composite film in which the adhesive layer is a non-selectable adhesive layer and a method for producing the same.
  • a ceramic separator and a heat-resistant layer were prepared in accordance with the method of Example 2 to obtain a composite film.
  • the preparation of the bonding layer slurry was carried out in the same manner as in Example 13, except that the bonding layer was formed by a doctor blade method to obtain a lithium ion battery separator Sa14 and a PE base film including a porous self-crosslinking polymer film, respectively.
  • the porous self-crosslinking polymer film Sb14 prepared as described above was found to have a porosity of 0%, a liquid absorption rate of 156%, and a conductivity of 5.25 mS/cm.
  • the ionic conductivity of the lithium ion battery separator Sa14 prepared as described above was tested to be 5.05 mS/cm.

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Abstract

一种锂离子电池隔膜，包括多孔基膜以及覆盖在所述多孔基膜的至少一侧表面上的耐热层，所述耐热层含有耐高温聚合物以及无机纳米颗粒，所述耐热层具有纤维网络状结构。还公开了该锂离子电池隔膜的制备方法以及包括该电池隔膜的锂离子电池。所述锂离子电池隔膜的制备工艺较为简单，得到的锂离子电池隔膜具有较好的柔韧性，在高温下具有良好的稳定性，高温热收缩率小，高温机械强度好。

Description

锂离子电池隔膜及其制备方法和锂离子电池
相关申请的交叉引用
本公开主张在2016年8月29日在中国提交的中国专利申请号No.201610750611.7的优先权，其全部内容通过引用包含于此。
技术领域
本公开涉及锂离子电池领域，具体地，涉及一种锂离子电池隔膜及其制备方法和锂离子电池。
背景技术
锂离子电池主要由正/负极材料、电解质、隔膜及电池外壳包装材料组成。隔膜是锂离子电池的重要组成部分，用于起着分隔正、负极，防止电池内部短路，允许电解质离子自由通过，完成电化学充放电过程的作用。隔膜的性能决定了电池的界面结构、内阻等，直接影响电池的倍率性能、循环性能以及安全性能(耐高温性能)等特性，性能优异的隔膜对提高电池的综合性能具有重要的作用，被业界称为电池的“第三电极”。
现有的锂离子电池隔膜可以由聚合物材料通过湿度相转化法形成，然而，由于聚合物材料的融化温度通常较低(400-500℃)而可能导致锂离子电池耐高温性能较差，并且聚合物材料不能吸附电池中产生的副反应产物等杂质。对此，现有技术采用由无机颗粒和粘结剂形成的耐热层，以提高锂离子电池隔膜的耐热性能。
例如，CN103474610A公开了一种采用静电纺丝/静电喷雾制备复合锂离子电池隔膜的方法，该方法的具体步骤为：(1)将高分子聚合物加入到有机溶剂中，机械搅拌溶解，形成透明溶液，制得静电纺丝液；(2)将无机纳米颗粒和高分子聚合物混合加入到有机溶剂中，机械搅拌，制得无机纳米颗粒悬浮液；(3)将步骤(1)制备的纺丝液静电纺丝制备下层纳米纤维膜，再将步骤(2)制备的无机纳米颗粒悬浮液经静电喷雾沉积到下层纳米纤维膜上，为中间层，最后，在无机颗粒层上接收一层静电纺纳米纤维膜，即制得复合锂离子电池隔膜。其中，步骤(2)中无机纳米颗粒与高分子聚合物的质量比为(0.8-0.98)：(0.2-0.02)。然而，该产品并不能真正地改善复合隔膜在更高温度下的稳定性能，主要是由于其所使用的高分子聚合物为PMMA、PAN、PVDF和P(VDF-HFP)中的一种或两种以上的混合物，其中，PMMA 的熔点为130-140℃，聚丙烯腈PAN的玻璃化转变温度约为90℃、碳化温度约为200℃，PVDF的熔点为170℃，无法起到改善高温下(>180℃)隔膜热收缩的作用。此外，该方法为先采用静电纺丝方式制备一层纤维膜，然后采用静电喷雾法制备一层无机-有机复合层，接着在无机-有机复合层表面再静电纺丝制备一层纤维层，这样形成的结构在常态下的拉伸强度和穿刺强度都较低，且PVDF-HFP在电解液中溶胀，无法起到保护作用。
发明内容
本公开的目的是为了提供一种新的锂离子电池隔膜及其制备方法和锂离子电池。
在现有的由无机颗粒和聚合物材料形成的耐热层中，由于无机颗粒的耐热性要优于常用的聚合物材料，因此，为了提高锂离子电池隔膜的耐高温性能，现有的耐热层中通常以无机颗粒作为主要成分，而聚合物材料含量较低且仅仅起到粘结作用。此外，由于高温聚合物粘结剂(熔点高)的粘结性能通常要低于低温聚合物粘结剂(熔点低)的粘结性能，因此，为了使得锂离子电池隔膜具有更高的强度，现有技术通常选用低温聚合物作为粘结剂。而本公开的发明人经过深入研究后发现，现有技术的这种耐热层虽然能够在一定程度上提高锂离子电池隔膜的耐热性能，但是其在高温下热收缩非常大，会导致无机颗粒的破裂并降低高温强度。而本公开的发明人通过深入研究后还发现，当采用耐高温聚合物作为耐热层的主要成分，而无机材料作为耐热层的改性材料，两种以特定的比例混合之后通过静电纺丝的方式使得耐热层形成具有纤维网络状结构时，耐高温聚合物形成的纤维作为骨架支撑隔膜在高温下的强度，而添加的无机纳米颗粒相当于一个一个的锚点钉扎纤维进一步增强复合隔膜在高温下的强度，并进一步减少隔膜在高温下的热收缩；同时由于陶瓷颗粒为纳米尺寸，能一定程度上限制高分子链之间的运动从而提高耐热高分子的软化温度，进一步增强复合隔膜的耐热性，相应的锂离子电池隔膜不仅具有较高的离子电导率，而且还能够提高耐热性以及在高温下的机械强度。基于此，完成了本公开。
具体地，本公开提供了一种锂离子电池隔膜，其中，所述锂离子电池隔膜包括多孔基膜以及覆盖在所述多孔基膜的至少一侧表面上的耐热层；所述耐热层含有耐高温聚合物以及无机纳米颗粒，且所述耐热层具有纤维网络状结构。
本公开还提供了一种锂离子电池隔膜的制备方法，该方法包括：
S1、提供多孔基膜；
S2、配制含有耐高温聚合物和无机纳米颗粒的纺丝溶液，并将所述纺丝溶液通过静电纺丝在所述多孔基膜的至少一侧表面上形成耐热层；本公开还提供了由上述方法制备得到的 锂离子电池隔膜。
此外，本公开还提供了一种锂离子电池，其中，该锂离子电池包括正极、负极、电解液以及位于所述正极和负极之间的锂离子电池隔膜，所述锂离子电池隔膜为上述锂离子电池隔膜。
本公开提供的锂离子电池隔膜在高温下(＞160℃)不仅具有很好的稳定性，高温热收缩率很小，而且高温机械强度好，比单纯采用耐高温聚合物纺丝得到的复合隔膜的耐热性和高温机械强度要好很多，而普通陶瓷(CCL)隔膜由于采用不耐热聚合物，在高温下要么表现出很大的热收缩，要么高温下出现聚合物融化而陶瓷颗粒之间连接松散的现象，从而使得整个锂离子电池隔膜不具有很高的机械强度。此外，本公开提供的锂离子电池隔膜的制备工艺较为简单，且得到的锂离子电池隔膜具有较好的柔韧性，易于收卷绕。
本公开的其它特征和优点将在随后的具体实施方式部分予以详细说明。
附图说明
附图是用来提供对本公开的进一步理解，并且构成说明书的一部分，与下面的具体实施方式一起用于解释本公开，但并不构成对本公开的限制。在附图中：
图1为由实施例1得到的耐热层的扫描电镜照片图，放大倍数为10000；
图2为由实施例1得到的耐热层的扫描电镜照片图，放大倍数为5000。
具体实施方式
以下对本公开的具体实施方式进行详细说明。应当理解的是，此处所描述的具体实施方式仅用于说明和解释本公开，并不用于限制本公开。
在本文中所披露的范围的端点和任何值都不限于该精确的范围或值，这些范围或值应当理解为包含接近这些范围或值的值。对于数值范围来说，各个范围的端点值之间、各个范围的端点值和单独的点值之间，以及单独的点值之间可以彼此组合而得到一个或多个新的数值范围，这些数值范围应被视为在本文中具体公开。
本公开提供的锂离子电池隔膜包括多孔基膜以及覆盖在所述多孔基膜的至少一侧表面上的耐热层；所述耐热层含有耐高温聚合物以及无机纳米颗粒，且所述耐热层具有纤维网络状结构。
根据本公开提供的锂离子电池隔膜，所述耐热层中无机纳米材料的含量越高，相应的耐高温性能也好，然而无机纳米材料的含量越高，相应的纤维网络状结构的形貌(强度和韧 性)会有所变差。综合考虑耐热层的耐高温性能和纤维网络状结构的形貌，可选地所述耐高温聚合物与无机纳米材料的重量比为100:(3-50)；可选地所述耐高温聚合物与无机纳米材料的重量比为100：(5-18)。可选地，所述耐热层由耐高温聚合物和无机纳米材料组成，可选地以所述耐热层的总重量100％计，其中耐热聚合物的含量为85-95重量％，无机纳米材料的含量为5-15wt％。
本公开对所述耐热层的厚度和纤维直径没有特别地限定。所述耐热层的单面厚度可选为0.5-30μm。所述耐热层中的纤维平均直径可选为100-2000nm。当所述耐热层的厚度以及其中纤维平均直径在上述可选范围内时可有效对正负极和隔膜进行粘结，提高电池循环性能。
根据本公开提供的锂离子电池隔膜，可选地，所述耐热层的单面面密度为0.2-15g/m2，例如为1-5g/m2。其中，面密度指的是单位面积基材隔膜上所敷物质的质量，由该指标可以知道基材隔膜上的敷料量。当所述耐热层的面密度在上述可选范围内时，能够有效保证电导率，不影响锂离子迁移，同时具有更好的粘结性能，利于提高电池的安全性能。
根据本公开提供的锂离子电池隔膜，可选地，所述耐热层的孔隙率为80％以上，例如为80-90％，如为80-85％。当所述耐热层的孔隙率在上述可选范围内时，能够有效保证锂离子电池隔膜的离子电导率。在本公开中，所述耐热层的孔隙率的测量方法包括：裁取特定体积的耐热层样品，称重，然后将耐热层样品浸泡在异丁醇中，待吸附平衡之后测样品重量，
Figure PCTCN2017097404-appb-000001
根据本公开的实施方式，所述耐热层通过将含有耐高温聚合物和无机纳米颗粒的纺丝溶液经静电纺丝而形成。
本公开对所述耐高温聚合物的种类没有特别地限定，可以为现有的各种耐高温性能较好的聚合物，可选地，所述耐高温聚合物的熔点不低于180℃，例如为200-600℃。所述耐高温聚合物的实例包括但不限于：聚醚酰亚胺(PEI)、聚酰亚胺(PI)、聚醚醚酮(PEEK)、聚醚砜(PES)、聚酰胺酰亚胺(PAI)、聚酰胺酸(PAA)和聚乙烯吡咯烷酮(PVP)中的至少一种。其中聚醚醚酮(PEEK)包括共聚醚醚酮(CoPEEK)和改性(均聚)聚醚醚酮。
根据本公开提供的锂离子电池隔膜，可选地，所述耐高温聚合物选自聚醚酰亚胺(PEI)和聚醚醚酮(PEEK)中的至少一种。采用该两种耐高温聚合物与无机颗粒混合进行静电纺丝得到纤维层时，该耐高温聚合物形成的纤维能够更高地作为骨架支撑隔膜在高温下的强度，而通过与无机颗粒的配合，能进一步减少隔膜在高温下的热收缩以及增强复合隔膜的耐热性，制备得到的电池隔膜具备良好的耐热性以及在高温下的具备良好的机械强度。
本公开对所述无机纳米颗粒的粒径和种类没有特别地限定。可选地，所述无机纳米颗粒的平均粒径为50nm-3μm，例如为50nm-1μm，如为50nm-0.4μm。所述无机纳米颗粒的实例包括但不限于：Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2、CNT、BN、SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α–V2O5、PbTiO3、TiB2、CaSiO3、分子筛、粘土和高岭土中的至少一种颗粒。
本公开对所述耐热层的厚度没有特别地限定，可选单面厚度为1-5μm，例如为1-3μm。
上述耐热层可以位于多孔基膜的一侧，也可以在多孔基膜两侧均设置上述耐热层。可选地，所述多孔基膜两侧面上均设有所述耐热层。
根据本公开的锂离子电池隔膜，其中所述多孔基膜可以为聚合物隔膜，也可以为陶瓷隔膜，所述陶瓷隔膜与本领域常规的陶瓷隔膜一样，同时包括聚合物隔膜和位于所述聚合物隔膜表面的陶瓷层；其中上述聚合物隔膜可采用现有的聚烯烃隔膜。所述聚烯烃隔膜为锂离子电池通用隔膜，包括聚丙烯(PP)隔膜、聚乙烯(PE)隔膜和PE/PP/PE三层隔膜等。在本公开中可选所述多孔基膜为陶瓷隔膜，且所述耐热层位于所述陶瓷隔膜中形成有陶瓷层一侧的表面上。
根据本公开对陶瓷隔膜中的陶瓷层并没有特殊要求，可以选择本领域常规采用的陶瓷层。然而，为了优化所述陶瓷隔膜的耐高温热收缩，在本公开中，可选地所述陶瓷层含有陶瓷颗粒和粘结剂，且所述陶瓷层在单位厚度(1μm)下的面密度ρ满足1.8mg/cm2＜ρ≤2.7mg/cm2，可选满足1.85mg/cm2≤ρ≤2.65mg/cm2，例如满足1.9mg/cm2≤ρ≤2.6mg/cm2。
本公开所提供的上述陶瓷隔膜，通过采用单位厚度(1μm)下的面密度控制在1.8mg/cm2＜ρ≤2.7mg/cm2的陶瓷层，能够提高陶瓷隔膜的耐高温热收缩性，使其耐热温度达到160℃以上，在不增加陶瓷层厚度的情况下改善其热稳定性能，从而不影响电池的能量密度。
根据本公开的锂离子电池隔膜，在一个实施方式中，在所述陶瓷层中，相对于100重量份的所述陶瓷颗粒，所述粘结剂的含量为2-8重量份，可选为4-6重量份。当将所述陶瓷层中各物质的含量控制在上述的范围内时，能够使得到的陶瓷隔膜具有更好的耐高温热收缩性能。
根据本公开的锂离子电池隔膜，在一种相对具体的实施方式中，在所述陶瓷层中，相对于100重量份的所述陶瓷颗粒，包括2-8重量份的粘结剂、0.3-1重量份的分散剂、0.5-1.8重量份的增稠剂、以及0-1.5重量份的表面处理剂，且所述分散剂的数均分子量在5万以下；可选地，在所述陶瓷层中，相对于100重量份的所述陶瓷颗粒，所述粘结剂的含量为4-6重量份，所述分散剂的含量为0.4-0.8重量份，所述增稠剂的含量为0.7-1.5重量份，所述表面处理剂的含量为0.5-1.2重量份。
根据本公开的锂离子电池隔膜，所述陶瓷层中陶瓷颗粒可以包括但不限于Al2O3(包括α,β,γ型)、SiO2、BaSO4、BaO、二氧化钛(TiO2、金红石或锐钛矿)、CuO、MgO、Mg(OH)2、LiAlO2、ZrO2、碳纳米管(CNT)、BN、SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α–V2O5、PbTiO3、TiB2、CaSiO3、分子筛(ZSM-5)、粘土、勃姆石和高岭土中的至少一种，可选采用Al2O3、SiO2和BaSO4中的至少一种。
当无机颗粒为Al2O3(尤其是α-Al2O3)、SiO2或BaSO4时，具有优异的热绝缘性和电化学稳定性，更有利于提高锂离子电池隔膜的热稳定性，从而提高电池的安全性能。
本公开的发明人通过大量实验发现，本公开提供的耐热层与上述陶瓷隔膜的相亲性优于与聚合物隔膜之间的相亲性；同时，陶瓷隔膜中陶瓷层的表面凹凸不平，具有大量颗粒突起，可为耐热层提供更多的附着点，利于提高耐热层在无机颗粒层上的粘结强度。耐热层可更好地将正负极和隔膜粘结为一个整体。同时，陶瓷隔膜的尺寸稳定性，抗热收缩性能更高。在上述耐热层具有优异粘附性的情况下，与上述无机颗粒层相配合，可提高制备得到的锂离子电池的硬度，并且循环时极片不易变形，安全性高。
根据本公开的锂离子电池隔膜，对于陶瓷层中的无机颗粒，在一个实施方式中，其粒径为200-800nm，可选为300nm-600nm。本公开的发明人发现，当无机颗粒层中的无机颗粒的粒径在上述范围内时，不但可有效避免形成陶瓷层所用浆液的凝聚，而且还有利于陶瓷隔膜透气性的提高。
根据本公开的锂离子电池隔膜，对于陶瓷层中粘结剂的选择可以参照本领域的常规选择。例如，可以为聚丙烯酸酯、聚偏氟乙烯与六氟丙烯的共聚物、聚偏氟乙烯与三氯乙烯的共聚物、聚丙烯腈、聚乙烯基吡咯烷酮、聚酰亚胺、聚乙烯醇等中的至少一种，可选为聚丙烯酸酯，例如为玻璃化转变温度满足-40℃至0℃的聚丙烯酸酯。玻璃化转变温度满足-40℃至0℃的聚丙烯酸酯，具体可以为(甲基)丙烯酸甲酯、(甲基)丙烯酸乙酯、(甲基)丙烯酸丁酯、(甲基)丙烯酸己酯的均聚物及共聚物等中的至少一种。当采用玻璃化转变温度满足-40℃至0℃的聚丙烯酸酯作为粘结剂时，能够在不影响陶瓷隔膜的粘结强度的基础上，改善其加工性能，更具工业应用前景。
此外，可选往上述聚丙烯酸酯粘结剂中引入交联性单体，例如，丙烯酸羟甲基和/或羟甲基丙烯酰胺，且将交联性单体的含量可选控制在粘结剂重量的8重量％以内，可选地控制在3-5重量％，这样可以使得该聚丙烯酸酯粘结剂发生轻度交联，从而改善陶瓷隔膜的耐水性并增加陶瓷层的粘结强度。
本公开对陶瓷层中分散剂的种类没有特别地限定，可以为现有的各种有助于陶瓷层浆液中各物质分散的且数均分子量为5万以下、可选为5000-20000的物质，可选为聚丙烯酸 盐、聚乙二醇醚、硅酸盐类化合物、磷酸盐类化合物和古尔胶中的至少一种，可选为聚丙烯酸盐、聚乙二醇醚和磷酸盐类化合物中的至少一种。其中，所述聚丙烯酸盐例如可以为聚丙烯酸钾、聚丙烯酸钠、聚丙烯酸锂等中的至少一种。所述聚乙二醇醚例如可以为聚乙二醇叔辛基苯基醚和/或聚乙二醇单月桂醚。所述磷酸盐类化合物例如可以为三聚偏磷酸钠和/或六聚偏磷酸钠。
本公开对陶瓷层中增稠剂的种类没有特别地限定，可选为聚丙烯酸盐、聚乙烯吡咯烷酮、纤维素类化合物和聚丙烯酰胺中的至少一种，可选为聚丙烯酸盐、丙烯酸共聚物和纤维素类化合物中的至少一种。其中，所述聚丙烯酸盐例如可以为聚丙烯酸钾、聚丙烯酸钠、聚丙烯酸锂等中的至少一种。所述丙烯酸共聚物是指丙烯酸与其他单体的共聚物，例如可以为丙烯酸与苯乙烯的共聚物、丙烯酸与丙烯酸乙酯的共聚物、丙烯酸与乙烯的共聚物等中的至少一种。所述纤维素类化合物例如可以为羧甲基纤维素钠、羧甲基纤维素钾、羟乙基纤维素等中的至少一种。此外，所述增稠剂的1重量％水溶液的粘度为1500-7000mPa·s，这样既能够很好地分散于陶瓷层浆液中，又有利于涂覆的进行，更有利于面密度的提高。此外，虽然所述分散剂和增稠剂均可以为聚丙烯酸盐，但是作为增稠剂的聚丙烯酸盐的数均分子量要远远高于作为分散剂的聚丙烯酸盐的分子量，作为增稠剂的聚丙烯酸盐的数均分子量通常为30万-150万，而作为分散剂的聚丙烯酸盐的数均分子量为5万以下。
本公开对所述表面处理剂的种类没有特别地限定，可选为3-缩水甘油醚氧基丙基三甲氧基硅烷和/或3-缩水甘油醚氧基丙基三乙氧基硅烷，这样能够进一步改善陶瓷颗粒和粘结剂之间的相互作用，增加陶瓷隔膜的强度。
根据本公开的锂离子电池隔膜，在一个实施方式中，所述陶瓷隔膜中聚合物隔膜的厚度为5-30μm，例如为6-25μm。此外，所述陶瓷层的单面厚度可选为1-5μm，例如为2-3.5μm，这样更有利于陶瓷隔膜耐高温热收缩性的改善以及透气性的提高。
根据本公开的锂离子电池隔膜，在一个实施方式中，所述锂离子电池隔膜中还包括粘结层，所述粘结层形成于所述锂离子电池隔膜的至少一侧表面的最外侧，粘结层的形成能够提高锂离子电池隔膜与正负极之间的粘性，增加锂离子电池隔膜的设置稳定性，提高电池的安全性能，并进一步提高锂离子电池隔膜的离子导电性。在本公开中，可选地，所述粘结层含有丙烯酸酯类交联聚合物以及苯乙烯-丙烯酸酯类交联共聚物，和/或，偏氟乙烯-六氟丙烯共聚物，且所述粘结层的孔隙率为40-65％。当所述陶瓷隔膜还包括上述特定的粘结层时，其不仅具有良好的耐高温热收缩性，而且还具有更高的粘结强度以及离子电导率。
“所述粘结层含有丙烯酸酯类交联聚合物以及苯乙烯-丙烯酸酯类交联共聚物和/或偏氟乙烯-六氟丙烯共聚物”指的是所述粘结层含有丙烯酸酯类交联聚合物与苯乙烯-丙烯酸酯类 交联共聚物而不含有偏氟乙烯-六氟丙烯共聚物，或者，含有丙烯酸酯类交联聚合物与偏氟乙烯-六氟丙烯共聚物而不含有苯乙烯-丙烯酸酯类交联共聚物，或者，同时含有丙烯酸酯类交联聚合物与苯乙烯-丙烯酸酯类交联共聚物以及偏氟乙烯-六氟丙烯共聚物。此外，“含有自交联型纯丙乳液以及自交联型苯丙乳液和/或偏氟乙烯和六氟丙烯的共聚乳液”也可类似地进行解释。
所述丙烯酸酯类交联聚合物是指由反应型丙烯酸酯类单体发生交联聚合得到的聚合物。所述丙烯酸酯类交联聚合物的交联度可以为2-30％，可选为5-20％。在本公开中，所述交联度是指交联聚合物的重量占聚合物总重量的百分比。此外，所述丙烯酸酯类交联聚合物的玻璃化转变温度可选为-20℃至60℃，例如为-12℃至54℃。根据本公开的实施方式，所述丙烯酸酯类交联聚合物为第二丙烯酸酯类交联聚合物、第三丙烯酸酯类交联聚合物、或者第一丙烯酸酯类交联聚合物与第二丙烯酸酯类交联聚合物和/或第三丙烯酸酯类交联聚合物的混合物；其中，所述第一丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述第一丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃。
所述苯乙烯-丙烯酸酯类交联共聚物是指由苯乙烯单体与反应型丙烯酸酯类单体发生共聚得到的共聚物。所述苯乙烯-丙烯酸酯类交联共聚物中苯乙烯结构单元与丙烯酸酯结构单元的重量比可以为0.5-2:1，可选为0.67-1.5:1。所述苯乙烯-丙烯酸酯类交联共聚物的交联度可以为2-30％，可选为5-20％。此外，所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度可选为-30℃至50℃，例如为-20℃至50℃。根据本公开的实施方式，所述苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃。
所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度可选为-65℃至-40℃，例如为-60℃至-40℃。根据本公开的实施方式，所述偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段，可选含有90-96重量％的聚偏氟乙烯链段和4-10 重量％的聚六氟丙烯链段；所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
根据本公开的实施方式，所述粘结层含有丙烯酸酯类交联聚合物和苯乙烯-丙烯酸酯类交联共聚物且不含有偏氟乙烯-六氟丙烯共聚物，所述丙烯酸酯类交联聚合物与苯乙烯-丙烯酸酯类交联共聚物的重量比为1：0.05-2，可选为1：1-2；或者，所述粘结层含有丙烯酸酯类交联聚合物和偏氟乙烯-六氟丙烯共聚物且不含有苯乙烯-丙烯酸酯类交联共聚物，所述丙烯酸酯类交联聚合物与偏氟乙烯-六氟丙烯共聚物的重量比为1：0.3-25，可选为1：0.4-19；或者，所述粘结层含有丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物和偏氟乙烯-六氟丙烯共聚物，所述丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物与偏氟乙烯-六氟丙烯共聚物的重量比为1：0.01-2：0.3-5，可选为1：0.05-1.5：0.45-3。本公开的发明人经过深入研究后发现，当采用以上几种聚合物按照上述特定的比例配合使用时，非常有利于电池隔膜吸液率和电导率的提高以及加工性的改善。
根据本公开的实施方式，所述粘结层含有第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物和苯乙烯-丙烯酸酯类交联共聚物且不含有偏氟乙烯-六氟丙烯共聚物，且所述第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物与苯乙烯-丙烯酸酯类交联共聚物的重量比为5-10：1：10-13；或者，
所述粘结层含有第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物和偏氟乙烯-六氟丙烯共聚物且不含有苯乙烯-丙烯酸酯类交联共聚物，所述第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物与偏氟乙烯-六氟丙烯共聚物的重量比为5-15：1：5-12；或者，
所述粘结层含有第二丙烯酸酯类交联聚合物和偏氟乙烯-六氟丙烯共聚物且不含有苯乙烯-丙烯酸酯类交联共聚物，所述第二丙烯酸酯类交联聚合物与偏氟乙烯-六氟丙烯共聚物的重量比为1：5-20；或者，
所述粘结层含有第二丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物和偏氟乙烯-六氟丙烯共聚物，所述第二丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物与偏氟乙烯-六氟丙烯共聚物的重量比为1：0.5-2：1-5；或者，
所述粘结层含有第三丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物和偏氟乙烯-六氟丙烯共聚物，所述第三丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物与偏氟乙烯-六氟丙烯共聚物的重量比为1：0.5-2：1-5；或者，
所述粘结层含有第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物和偏氟乙烯-六氟丙烯共聚物，第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物、苯乙烯-丙烯酸酯类交联共聚物与偏氟乙烯-六氟丙烯共聚物的重量比为 10-15：1：0.5-2：5-10；
其中，所述第一丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段；所述第一丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃，所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃，所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
根据本公开，可选地，所述粘结层中还含有丙烯腈-丙烯酸酯共聚物、氯丙共聚物和丁苯共聚物中的至少一种。当所述粘结层中还含有丙烯腈-丙烯酸酯共聚物时，有利于提高电池隔膜在电池内部的离子电导率；当所述粘结层中还含有氯丙共聚物和/或丁苯共聚物时，有利于降低电池隔膜的吸液率，使吸液率不至于太高，因为吸液率过高会使得电池内部正极和负极缺乏电解液而裂化电池性能。
当所述粘结层中还含有丙烯腈-丙烯酸酯共聚物时，所述丙烯腈-丙烯酸酯共聚物与丙烯酸酯类交联聚合物的重量比可选为0.05-2：1，例如为0.08-1.85：1。当所述粘结层中还含有氯丙共聚物时，所述氯丙共聚物与丙烯酸酯类交联聚合物的重量比可选为0.15-7：1，例如为0.2-6：1。当所述粘结层中还含有丁苯共聚物时，所述丁苯共聚物与丙烯酸酯类交联聚合物的重量比可选为0.05-2：1，例如为0.08-1.85：1。
此外，所述粘结层的单面面密度可选为0.05-0.9mg/cm2，例如为0.1-0.6mg/cm2。所述粘结层的单面厚度可选为0.1-1μm，例如为0.2-0.6μm。
本公开提供的锂离子电池隔膜的制备方法包括如下步骤：
S1、提供多孔基膜；
S2、配制含有耐高温聚合物和无机纳米颗粒的纺丝溶液，并将所述纺丝溶液通过静电纺丝法在所述多孔基膜的至少一侧表面上形成耐热层；可选以所述纺丝溶液中耐高温聚合物与无机纳米材料的重量比为100：(3-50)；例如为100：(5-18)。
根据本公开提供的锂离子电池的制备方法，所述纺丝溶液中的溶剂用于将耐高温聚合物溶解并将无机纳米颗粒分散，以便后续静电纺丝工序的顺利实现。所述溶剂可以为现有的各种能够实现上述目的的惰性液态物质，其具体实例包括但不限于：N-甲基吡咯烷酮(NMP)、N’N-二甲基甲酰胺(DMF)、N’N-二甲基乙酰胺(DMAC)、甲苯、丙酮、四氢呋喃等中的至少一种。此外，所述溶剂的用量可选使得到的纺丝溶液中耐高温聚合物的浓度为5-30重量％，可选为8-25重量％。当纺丝聚合物(耐高温聚合物)的相对分子质量固定时，在其他条件一定的情况下，纺丝溶液的浓度是影响分子链在溶液中缠结的决定性因素。高分子溶液按照浓度大小及分子链形态的不同，可以分为高分子稀溶液、亚浓溶液、浓溶液三种。在稀溶液中，分子链相互分离，分布均一，随着溶液浓度的增加，分子链之间相互穿插交叠，发生缠结。稀溶液与亚浓溶液的分界浓度称为接触浓度，是指随着溶液浓度的增加，分子链发生接触，随后发生交叠的浓度。亚浓溶液与浓溶液的分界浓度称为缠结浓度，是指随着溶液浓度的进一步增加，分子链相互穿插，相互缠结的浓度。本公开中，当纺丝溶液浓度在上述可选范围内时，可有效的保证成丝性能。此外，随着纺丝溶液浓度的升高，高分子缠结度增加，成丝性更好。
所述耐高温聚合物和无机纳米颗粒的种类已经在上文中有所描述，在此不作赘述。
所述静电纺丝的基本原理为本领域技术人员公知，具体为在喷射装置和接受装置之间施加电压，从源自喷射装置的锥体端部的纺丝溶液形成射流，并在电场中被拉伸，最终在接受装置上形成纤维。其中，所述接受装置包括滚筒(可旋转)或者接收板。所述静电纺丝法通常包括有针头纺丝法和无针头纺丝法，具体过程均为本领域技术人员所公知，在此不作赘述。
当所述静电纺丝法为有针头纺丝法时，纺丝溶液的流速可选为0.3-5mL/h，例如为0.6-2mL/h；纺丝温度可选为25-70℃，例如为30-50℃；纺丝湿度可选为2％-60％，例如为2％-50％；纺丝电压可选为5-25kV，例如为8-20kV。当流速在上述可选范围内时，可保证获得合适的纤维直径，同时可有效避免堵塞针头，保证纺丝的顺利进行。尤其是在采用本公开提供的混合溶剂的前提下，控制流速在上述范围内可获得具有优异孔隙率和粘结性能的纤维层。当纺丝温度和湿度在上述范围内时，与前述的混合溶剂配合，保证纺丝获得的纤维顺利成丝后干燥，避免纤维出现粘连而导致孔隙率下降，并可避免纤维层的粘结性能下降。当电压在上述范围内时，可有效激发纺丝溶液形成射流，从而在电场中产生有效的拉伸作用，获得直径合适的纤维，保证形成的纤维的形态，利于提高纤维层的孔隙率和粘结性能。此外，所述接收装置可选为滚筒，且滚筒的转速可选为100-6000rpm，例如为1000-2000rpm。当用于收集纤维的收集装置的表面的线速度过小时，由于快速运动的射流为混乱状态，此时形成 的纤维会在收集装置表面呈无规则堆积的状态分布，得到的纤维层的机械强度较差。而当收集装置表面线速度达到一定程度后，形成的纤维会以圆周的方式紧紧地附着在收集装置表面上，纤维沉积方向相同，并且基本处于笔直状态，即产生笔直同向延伸的纤维束。另一方面，当收集装置表面线速度过大时，由于过快的接收速度会破坏纤维射流，无法得到连续纤维。通过对常规的静电纺丝工艺的不断试验，发明人发现，当收集装置的转速为100-6000rpm时，方可获得具有笔直同向延伸的纤维束。在一个实施方式中，当收集装置的转速为1000-2000rpm时，获得的纤维层中，纤维的形态更好，更利于提高纤维层的机械强度。
当所述静电纺丝法为无针头纺丝法时，纺丝的条件可选包括：温度为25-70℃，湿度为2％-60％，液池移动速度为0-2000mm/sec，基材移动速度0-20000mm/min(此时收集装置为板状，未转动)或者滚筒转速为100-6000rpm(此时收集装置为滚筒)，正极电压(产生纤维的源头端的电压)为0-150kV，负极电压(收集装置的电压)为-50至0kV，电压差(源头端与收集装置之间的电压差)为10-100kV；可选包括：温度为30-50℃，湿度为2％-50％，液池移动速度为100-400mm/sec，基材移动速度为1000-15000mm/min或者滚筒转速为1000-2000rpm，正极电压为10-40kV，负极电压为-30-0kV，电压差为20-60kV。
本公开的发明人通过大量实验发现，在纺丝溶液中耐高温聚合物浓度在前述可选范围的前提下，通过上述条件的静电纺丝工艺，可实现溶剂挥发速度与纤维形成速度的良好匹配，可获得形貌好，粘附性更高，耐热层中丝与丝之间粘附性更好的纤维层，并且其孔隙率可达到80％以上，可选为80-90％，例如为80-85％。
本公开对所述耐热层中纤维直径和厚度没有特别地限定，具体可以通过对具体工艺条件的控制进行更改，可选地，所述纤维平均直径为100-2000nm，所述耐热层的单面厚度为0.5-30μm。可选地，通过上述方法制备得到的纤维层的单面面密度为0.2-15g/m2。
根据本公开提供的锂离子电池隔膜的制备方法，上述静电纺丝可在多孔基膜一侧上进行，也可在多孔基膜两侧进行。在一个实施方式中，步骤S2中，通过静电纺丝，在所述多孔基膜的两个侧面上均形成所述耐热层。此时，先在多孔基膜一侧进行静电纺丝，选择性性进行热辊压并干燥后，在多孔基膜另一侧再进行静电纺丝，并选择性进行热辊压并干燥即可。
根据本公开，静电纺丝结束后，将膜取下，可选择性地在50-120℃、0.5-15Mpa下进行压膜处理，例如进行热辊压(热滚压条件为：温度为50-60℃，压力为1-15MPa)，然后在50℃下鼓风干燥24h。
根据本公开提供的锂离子电池隔膜的制备方法，多孔基膜可选为陶瓷隔膜，所述陶瓷隔膜包括聚合物隔膜和位于所述聚合物隔膜表面的陶瓷层；耐热层形成在所述陶瓷隔膜中陶瓷层的表面上。根据本公开，利用陶瓷隔膜的陶瓷层中含有无机颗粒层的特点，使得耐热层 可以更牢固地粘结在陶瓷层的表面，一方面可有效提高制备得到的锂离子电池隔膜的剥离强度，另一方面，该无机颗粒层位于聚合物隔膜与耐热层之间，可赋予锂离子电池隔膜整体优异的抗热收缩性能。
根据本公开的制备方法，步骤S1中陶瓷隔膜的制备方法包括：S11、提供聚合物隔膜；S12、将陶瓷颗粒、粘结剂、分散剂和增稠剂按照重量比100：(2-8)：(0.3-1)：(0.5-1.8)的比例搅拌混合得到陶瓷层浆液，并将所述陶瓷层浆液涂覆于所述聚合物隔膜的至少一侧表面上，烘干得到陶瓷层；其中所述分散剂的数均分子量为5万以下。
根据本公开的制备方法，综合考虑陶瓷层浆液中各原料的分散性和陶瓷层浆液的稳定性，可选地，在步骤S12中，所述搅拌的转速可选为3000-10000rpm，可选为3000-9000rpm。当将形成陶瓷层浆液的各物质置于上述可选转速下进行混合，更有利于陶瓷层面密度的提高。
根据本公开的制备方法，可选地，将陶瓷颗粒、粘结剂、分散剂和增稠剂按照上述重量比例混合，当所述分散剂的用量低于0.3重量份和/或增稠剂的用量低于0.5重量份(相对于100重量份的陶瓷颗粒，下同)时，可能会导致陶瓷层浆液分散性不足，难以形成较高密堆积从而获得本公开的1.8mg/cm2＜ρ≤2.7mg/cm2的面密度；当所述分散剂的用量高于1重量份和/或增稠剂的用量高于1.8重量份时，可能会影响锂离子电池隔膜的透气性从而影响电池输出特性。当所述粘结剂的用量低于2重量份时，可能会导致粘结强度不足；当所述粘结剂的用量高于8重量份时，可能会严重影响锂离子电池隔膜的透气性。当所述分散剂的数均分子量高于5万可能会影响陶瓷层浆液分散效果，降低面密度。
根据本公开提供的制备方法，可选地，步骤S12中，将陶瓷颗粒、粘结剂、分散剂和增稠剂按照重量比100：(4-6)：(0.4-0.8)：(0.7-1.5)的比例搅拌混合。将所述陶瓷层浆液中各物质的用量控制在上述可选范围内时，能够使得到的陶瓷层具有更高的面密度以及更好的耐高温热收缩性能。
此外，所述陶瓷颗粒、粘结剂、分散剂和增稠剂的种类和性质已经在上文中有所描述，在此不作赘述。
根据本公开的实施方式，所述陶瓷层浆液中还含有表面处理剂，所述表面处理剂为3-缩水甘油醚氧基丙基三甲氧基硅烷和/或3-缩水甘油醚氧基丙基三乙氧基硅烷，这样能够进一步改善陶瓷颗粒和粘结剂之间的相互作用，增强陶瓷层的强度。此外，相对于100重量份的所述陶瓷颗粒，所述表面处理剂的用量可选为1.5重量份以下，可选为0.5-1.2重量份，这样更有利于陶瓷层透气性的提高。
根据本公开的制备方法，在一个实施方式中，步骤S12中混合得到的陶瓷层浆液中还 可以含有十二烷基苯磺酸钠等表面活性剂，这些表面活性剂的用量均可以为本领域的常规选择，对此本领域技术人员均能知悉，在此不作赘述。
根据本公开的一种具体实施方式，步骤S12包括将陶瓷颗粒、分散剂和增稠剂在3000-10000rpm的转速下高速搅拌0.5-3小时，再加入表面处理剂并继续搅拌0.5-3小时，然后加入粘结剂并在3000-4000rpm的转速下搅拌0.5-2小时，接着将得到的陶瓷层浆料涂覆于聚合物隔膜的至少一侧表面上，然后烘干以在所述聚合物隔膜的至少一侧表面上形成陶瓷层；其中陶瓷颗粒、粘结剂、分散剂和增稠剂按照重量比100：(2-8)：(0.3-1)：(0.5-1.8)的比例投料，且所述分散剂的数均分子量为5万以下。其中，所述烘干的温度为50-80℃。可选地，步骤S12中在所述聚合物隔膜的两个表面上均形成所述陶瓷层。
根据本公开的制备方法，可选地，所述陶瓷层浆料的用量可选使得到的陶瓷层的单面厚度为1-5μm，可选为2-3.5μm，这样更有利于陶瓷层耐高温热收缩性的改善以及透气性的提高。
根据本公开的制备方法，该方法还包括步骤S3，在由步骤S2所得到的复合膜的至少一侧表面上形成粘结层。该粘结层的形成方法可以参照本领域的常规技术手段。
根据本公开的实施方式，步骤S3包括将含有自交联型纯丙乳液以及自交联型苯丙乳液和/或偏氟乙烯和六氟丙烯的共聚乳液的粘结层浆料附着在由步骤S2所得到的复合膜的至少一侧表面上，并干燥以形成孔隙率为40-65％的粘结层。此时，所述锂离子电池隔膜不仅具有良好的耐高温热收缩性，而且还具有更高的离子导电率以及粘结强度，更具工业应用前景。
所述自交联型纯丙乳液是指由反应型丙烯酸酯类单体发生乳液聚合得到的乳液。所述自交联型纯丙乳液中的丙烯酸酯类交联聚合物的交联度可以为2-30％，可选为5-20％。此外，所述自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度可选为-20℃至60℃，可选为-12℃至54℃。根据本公开的实施方式，所述自交联型纯丙乳液为第二自交联型纯丙乳液、第三自交联型纯丙乳液、或者第一自交联型纯丙乳液与第二自交联型纯丙乳液和/或第三自交联型纯丙乳液的混合物；所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二 自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃。
所述自交联型苯丙乳液是指由苯乙烯单体与反应型丙烯酸酯类单体发生共聚得到共聚物乳液。其中，所述苯乙烯-丙烯酸酯类共聚物中苯乙烯结构单元与丙烯酸酯结构单元的重量比可以为0.5-2:1，可选为0.67-1.5:1。所述自交联型苯丙乳液中的苯乙烯-丙烯酸酯类交联共聚物的交联度可以为2-30％，可选为5-20％。此外，所述自交联型苯丙乳液中的苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度可选为-30℃至50℃，可选为-20℃至50℃。根据本公开的实施方式，所述自交联型苯丙乳液中的苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃。
所述偏氟乙烯和六氟丙烯的共聚乳液中的偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度可选为-65℃至-40℃，可选为-60℃至-40℃。根据本公开的实施方式，所述偏氟乙烯和六氟丙烯的共聚乳液中的偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段，可选含有90-96重量％的聚偏氟乙烯链段和4-10重量％的聚六氟丙烯链段；所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度可选为-60℃至-40℃。
所述偏氟乙烯和六氟丙烯的共聚乳液可以通过商购得到，也可以通过现有的各种方法制备得到，还可以通过将偏氟乙烯-六氟丙烯共聚物粉末配置成乳液而得到。根据本公开的一种具体实施方式，所述偏氟乙烯和六氟丙烯的共聚乳液通过以下方法制备得到：
(1)将分散剂溶解于水中，并选择性地调节其pH值，得到分散剂的水溶液A；
(2)将偏氟乙烯-六氟丙烯共聚物粉末在搅拌下缓慢加入到分散剂的水溶液A中，待偏氟乙烯-六氟丙烯共聚物粉末加完之后，先低速搅拌，后高速搅拌，最后再高压均质分散，形成偏氟乙烯和六氟丙烯的共聚乳液。
所述分散剂为水溶性聚合物分散剂，包括离子型(聚电解质)和非离子型两类。其中，所述离子型分散剂为聚羧酸类分散剂，其由含羧基的乙烯基单体(如丙烯酸、马来酸酐等)均聚或与其他单体共聚，后用碱中和醇酯化得到。所述离子型分散剂的实例包括但不限于：聚丙烯酸(PAA)、聚乙烯亚胺(PEI)、十六烷基三甲基溴化铵(CTAB)、聚酰胺、聚丙烯酰胺(PAM)、丙烯酸-丙烯酸酯类共聚物、丙烯酸-丙烯酰胺的共聚物[P(AA/AM)]、丙烯酸铵-丙烯酸酯类的共聚物、苯乙烯-马来酸酐共聚物(SMA)、苯乙烯-丙烯酸共聚物、丙烯酸-马来酸酐共聚物、马来酸酐-丙烯酰胺共聚物等。所述非离子型分散剂包括聚乙二醇(PEG)、聚乙烯醇(PVA)、聚乙烯吡咯烷酮(PVP)、脂肪醇聚氧乙烯醚(JFC)等。所述分散剂的 重均分子量为100-500000g/mol，可选1000-100000g/mol。所述分散剂的水溶液A的浓度为0.01-10重量％，可选为0.05-5重量％，可选为0.1-2重量％。所述分散剂的用量为所用偏氟乙烯-六氟丙烯共聚物粉末用量的0.05-10重量％，可选0.1-6重量％，可选0.1-2重量％。当所采用的离子型分散剂为阴离子型聚合物(如PAM)时，将溶液调节至pH＝8-9，可使阴离子型聚合物完全解离，从而对偏氟乙烯-六氟丙烯共聚物粉末进行有效地保护，并使其稳定地分散在水相里。当所采用的离子型分散剂为阳离子型聚合物(如PEI，CTAB)时，将溶液调节至pH＝4-5，可使阳离子型聚合物很好地解离，从而对偏氟乙烯-六氟丙烯共聚物粉末进行有效地保护，使其稳定地分散在水相里。当所采用的分散剂为非离子型聚合物分散剂时，不调节溶液的pH值。
根据本公开的实施方式，所述粘结层浆料含有自交联型纯丙乳液与自交联型苯丙乳液且不含有偏氟乙烯和六氟丙烯的共聚乳液，所述自交联型纯丙乳液与自交联型苯丙乳液的固含量的重量比为1：0.05-2，可选为1：1-2；或者，所述粘结层浆料含有自交联型纯丙乳液与偏氟乙烯和六氟丙烯的共聚乳液且不含有自交联型苯丙乳液，所述自交联型纯丙乳液与偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：0.3-25，可选为1：0.4-19；或者，所述粘结层浆料含有自交联型纯丙乳液、自交联型苯丙乳液、偏氟乙烯和六氟丙烯的共聚乳液，所述自交联型纯丙乳液、自交联型苯丙乳液、偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：0.01-2：0.3-5，可选为1：0.05-1.5：0.45-3。本公开的发明人经过深入研究后发现，当采用以上几种聚合物乳液按照上述特定的比例配合使用时，非常有利于陶瓷隔膜吸液率和电导率的提高以及加工性的改善。
根据本公开的一种特别可选的实施方式，所述粘结层浆料含有第一自交联型纯丙乳液、第二自交联型纯丙乳液和自交联型苯丙乳液且不含有偏氟乙烯和六氟丙烯的共聚乳液，第一自交联型纯丙乳液、第二自交联型纯丙乳液与自交联型苯丙乳液的固含量的重量比为5-10：1：10-13；或者，
所述粘结层浆料含有第一自交联型纯丙乳液、第二自交联型纯丙乳液以及偏氟乙烯和六氟丙烯的共聚乳液且不含有自交联型苯丙乳液，所述第一自交联型纯丙乳液、第二自交联型纯丙乳液与偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为5-15：1：5-12；或者，
所述粘结层浆料含有第二自交联型纯丙乳液以及偏氟乙烯和六氟丙烯的共聚乳液且不含有自交联型苯丙乳液，所述第二自交联型纯丙乳液与偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：5-20；或者，
所述粘结层浆料含有第二自交联型纯丙乳液、自交联型苯丙乳液以及偏氟乙烯和六氟丙烯的共聚乳液，所述第二自交联型纯丙乳液、自交联型苯丙乳液与偏氟乙烯和六氟丙烯的 共聚乳液的固含量的重量比为1：0.5-2：1-5；或者，
所述粘结层浆料含有第三自交联型纯丙乳液、自交联型苯丙乳液以及偏氟乙烯和六氟丙烯的共聚乳液，所述第三自交联型纯丙乳液、自交联型苯丙乳液与偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：0.5-2：1-5；或者，
所述粘结层浆料含有第一自交联型纯丙乳液、第二自交联型纯丙乳液、自交联型苯丙乳液以及偏氟乙烯和六氟丙烯的共聚乳液，第一自交联型纯丙乳液、第二自交联型纯丙乳液、自交联型苯丙乳液与偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为10-15：1：0.5-2：5-10；
所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述自交联型苯丙乳液中的苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述偏氟乙烯和六氟丙烯的共聚乳液中的偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段；所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃，所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃，所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
根据本公开，可选地，所述粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液、氯丙乳液和丁苯胶乳中的至少一种。当所述粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液时，有利于提高电池隔膜在电池内部的离子电导率；当所述粘结层浆料中还含有氯丙乳液和/或丁苯胶乳时，有利于降低电池隔膜的吸液率，使吸液率不至于太高，因为吸液率过高会使得电池内部正极和负极缺乏电解液而裂化电池性能。
当所述粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液时，所述丙烯腈和丙烯酸酯的共聚乳液的固含量与自交联型纯丙乳液的固含量的重量比可选为0.05-2：1，可选为 0.08-1.85：1。当所述粘结层浆料中还含有氯丙乳液时，所述氯丙乳液的固含量与自交联型纯丙乳液的固含量的重量比可选为0.15-7：1，可选为0.2-6：1。当所述粘结层浆料中还含有丁苯胶乳时，所述丁苯胶乳的固含量与自交联型纯丙乳液的固含量的重量比可选为0.05-2：1，可选为0.08-1.85：1。
此外，为了更有利于所述粘结层浆料的附着，可选地，所述粘结层浆料的总固含量为0.5-25重量％，可选为1-20重量％，可选为1-10重量％。
所述附着的方法可选采用喷涂法和/或丝网印刷法，通过喷涂法和/或丝网印刷法形成不连续覆盖从而直接形成具有上述孔隙率的多孔膜，这样能够制备出多孔(不连续)自交联聚合物涂层，而不需要相分离的过程。
本公开对所述喷涂和丝网印刷的条件没有特别地限定。例如，所述喷涂温度可选为30-80℃，可选为40-75℃。所述丝网印刷的温度可选为30-80℃，可选为40-75℃。
所述粘结层浆料的用量可选使得形成的粘结层的单面厚度为0.1-1μm，可选为0.2-0.6μm。
本公开还提供了由上述方法制备得到的锂离子电池隔膜。
此外，本公开还提供了一种锂离子电池，所述锂离子电池包括正极、负极、电解质和隔膜，其中，所述隔膜为上述陶瓷隔膜。
所述电解液为本领域技术人员公知，其通常由电解液锂盐和有机溶剂组成。其中，电解液锂盐采用可离解的锂盐，例如，可以选自六氟磷酸锂(LiPF6)、高氯酸锂(LiClO4)、四氟硼酸锂(LiBF4)等中的至少一种，有机溶剂可以选自碳酸乙烯酯(EC)、碳酸丙烯酯(PC)、碳酸二甲酯(DMC)、碳酸甲乙酯(EMC)和碳酸二乙酯(DEC)、碳酸亚乙烯酯(VC)等中的至少一种。可选地，所述电解液中电解液锂盐的浓度为0.8-1.5mol/L。
所述正极是由用于锂离子电池的正极材料、导电剂和粘结剂调成浆料涂布于铝箔上制成。所用的正极材料包括任意可用于锂离子电池的正极材料，例如，氧化钴锂(LiCoO2)、氧化镍锂(LiNiO2)、氧化锰锂(LiMn2O4)、磷酸亚铁锂(LiFePO4)等中的至少一种。
所述负极是由用于锂离子电池的负极材料、导电剂和粘结剂调成浆料涂布于铜箔上制成。所用负极材料包括任意可用于锂离子电池的负极材料，例如，石墨、软碳、硬碳等中的至少一种。
本公开提供的锂离子电池的主要改进之处在于采用了一种新的锂离子电池隔膜，而正极、负极、电池隔膜和电解液的排布方式(连接方式)可以与现有技术相同，对此本领域技术人员均能知悉，在此不作赘述。
本公开提供的锂离子电池的制备方法包括将正极、隔膜和负极依次层叠或卷绕成极芯， 然后往所述极芯中注入电解液并封口，其中，所述隔膜为上述锂离子电池隔膜。
其中，所述正极、负极和电解液的材质或组成已经在上文中有所描述，在此不作赘述。
以下将通过实施例对本公开进行详细描述。
以下实施例和对比例中，原料的物化参数如下：
(1)自交联型纯丙乳液的成分：
1.1)1040：聚丙烯酸丁酯链段占15重量％，聚甲基丙烯酸甲酯链段占75重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝54℃，固含量为50重量％，上海爱高化工有限公司；
1.2)1005：聚丙烯酸丁酯链段占55重量％，聚甲基丙烯酸甲酯链段占35重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝-12℃，固含量为50重量％，上海爱高化工有限公司；
1.3)1020：聚丙烯酸丁酯链段占25重量％，聚甲基丙烯酸甲酯链段占65重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝40℃，固含量为50重量％，上海爱高化工有限公司。
(2)自交联型苯丙乳液的成分：
S601：聚苯乙烯链段占45重量％，聚丙烯酸丁酯链段占35重量％，聚甲基丙烯酸甲酯链段占10重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝22℃，固含量为50重量％，上海爱高化工有限公司。
(3)偏氟乙烯和六氟丙烯的共聚乳液：
10278：聚偏氟乙烯链段占95重量％，聚六氟丙烯链段占5重量％，重均分子量Mw＝450000，玻璃化温度为-55℃，固含量为30重量％，阿科玛。
在以下实施例和对比例中，性能参数按照如下方法测定：
(1)陶瓷层的面密度测试：取10cm2×10cm2隔膜纸(未形成耐热层之前的陶瓷隔膜)和PE基膜，称其重量分别为m1(mg)和m2(mg)，测其膜厚分别为d1(μm)和d2(μm，陶瓷层在单位厚度下的面密度＝(m1-m2)×ρAl2O3/[10×10×(d1-d2)×10-4×ρ]，其中，ρAl2O3为三氧化二铝的真密度，ρ为所用陶瓷颗粒的真密度；
(2)陶瓷层透气性(格利值)测试：将陶瓷隔膜剪切为面积6.45cm2的陶瓷隔膜样品，利用格利值测试仪GURLEY-4110，压力(水柱高)12.39cm，测定100ml气体(空气)透过前述陶瓷隔膜样品所需要的时间(s/100ml)，其数值越小，表明透气性越好。
(3)陶瓷层剥离强度的测试：分别按照如下实施例和对比例各自的工艺制备仅包括单 面陶瓷层且不包括耐热层和粘结层的陶瓷隔膜，并从中裁取40mm×100mm的样品，用胶带把陶瓷隔膜两面分别固定在固定夹具和活动夹具上，180℃反向拉伸使陶瓷层和基材膜剥离，所需的拉力越大，则陶瓷隔膜的剥离强度就越高，说明粘结强度也就越高。
(4)陶瓷隔膜的热稳定性测试：从陶瓷隔膜中裁取5cm×5cm的陶瓷隔膜试样，分别放置于120℃和160℃烘箱中烘烤1小时，对比烘烤前后的面积变化，取面积的变化值与原面积的比值(收缩率)衡量陶瓷隔膜的热稳定性，不超过5％为A，大于5％为B。
(5)耐热层孔隙率测试：裁取一定体积的耐热层样品，称重，然后将耐热层样品浸泡在异丁醇中，待吸附平衡之后测样品重量，其
Figure PCTCN2017097404-appb-000002
(6)力学强度测试：采用深圳君瑞的万能试验机(均校准过)对锂离子电池隔膜的拉伸性能和针刺强度进行测定，其中，测试温度均为25℃；
(7)热收缩率测试：将锂离子电池隔膜裁成6cm×6cm的样品，置于烘箱中，分别在120℃、140℃、160℃、180℃下烘烤1h，测量样品的长宽，并按照以下公式计算热收缩率：
热收缩率＝(1-热收缩之后样品的长度/6)×100％；
(8)粘结层孔隙率测试：将实施例11-23得到的多孔自交联聚合物膜Sb1-Sb13分别裁成直径为17mm的圆片，测量厚度，称好质量后在正丁醇中浸泡2h，然后取出且用滤纸吸干膜表面的液体并称量出此时的质量。按照如下公式计算孔隙率：
Figure PCTCN2017097404-appb-000003
P为孔隙率，M0为干膜的质量(mg)，M为在正丁醇中浸泡2h后的质量(mg)，r为膜的半径(mm)，d为膜的厚度(μm)。
(9)粘结层的面密度：分别取0.2m×0.2m的PE基膜和含有粘结层的PE基膜，称其重量分别为M0(g)和M(g)，面密度＝[(M-M0)/0.04]g/m2。
(10)粘结层吸液率测试：将实施例11-23得到的多孔自交联聚合物膜Sb1-Sb13裁成直径为17mm的圆片，干燥好，称好质量后浸入到电解液(该电解液含有32.5重量％的EC(碳酸乙烯酯)、32.5重量％的EMC(乙基甲基碳酸酯)、32.5重量％的DMC(二甲基碳酸酯)、2.5重量％的VC(碳酸亚乙烯酯)和1mol/L LiPF6(六氟磷酸锂))中24h，然后取出用滤纸吸干膜表面的液体并称量出此时的质量，操作都在充满氩气的手套箱中进行，接着按照以下公式计算吸液率：
吸液率％＝(Wi-W)/W×100％
其中，W为干膜的质量(g)；Wi为干膜在电解液中浸泡了24h后的质量(g)。
(11)离子电导率的测试：采用交流阻抗测试，具体地，将如上各实施例和对比例中所制备的锂离子电池隔膜分别裁成直径为17mm的圆片，烘干后，放在两个不锈钢(SS)电极之间，吸收足够量的电解液(该电解液含有32.5重量％的EC(碳酸乙烯酯)、32.5重量％的EMC(乙基甲基碳酸酯)、32.5重量％的DMC(二甲基碳酸酯)、2.5重量％的VC(碳酸亚乙烯酯)和1mol/L LiPF6(六氟磷酸锂))，然后密封于2016型扣式电池后，进行交流阻抗实验，线性与实轴的交点即为电解质的本体电阻，由此可以计算得到离子电导率：σ＝L/A·R(其中L表示隔膜的厚度(cm)，A为不锈钢板与隔膜的接触面积(cm2)，R为电解液的本体电阻(mS))。
实施例1(多孔基膜(PE基膜)-耐热层两层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
将聚醚酰亚胺(PEI，商购自沙伯基础创新塑料(上海)有限公司，熔点为370-410℃，下同)与Al2O3颗粒(平均粒径为200nm，下同)按重量比10：1(即100：10)加入N,N-二甲基吡咯烷酮(NMP)中，然后在70℃水浴下磁力搅拌充分混合，形成浓度为15wt％的纺丝溶液。
将PE基膜(购自日本SK公司，牌号为BD1201，厚度为11μm，下同)的一侧表面上包裹在滚筒上(收集装置)，在该PE基膜的表面上以有针头静电纺丝法对上述纺丝溶液进行静电纺丝。调节静电纺丝参数如下：接收距离为12cm，温度为25℃，湿度为50％，针头内径为0.46mm，针头移动速度为6.6mm/sec，电压为10kV，流速为0.3mL/h，滚筒转速为2000rpm。
静电纺丝结束后，将PE基膜取下，在100℃、15MPa下压膜1min，然后在50℃下鼓风干燥24h，得到形成有耐热层(厚度为3μm)的锂离子电池隔膜F1，其扫描电镜(SEM)照片图如图1和图2所示。如图1和图2可以看出耐热层具有纤维网络状结构，其中纤维粗细比较均匀，并没有出现珠粒和聚合物团聚的现象，且纤维之间互相交缠在一起，形成了大量的孔隙，并且部分的纤维表面能清楚的看见无机颗粒的存在，而且无机颗粒没有发生团聚。
采用TEM Macrography软件测量SEM图中纤维的直径，记录数据，最终计算得到的纤维平均直径为300nm，耐热层的面密度为3.3g/m2，孔隙率为85％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为145Mpa和148MPa，针刺强度为0.530kgf，离子电导率为7.8mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3.8％、6.2％，纵向热收缩率分别为：0％、0％、4％、6.6％。
对比例1
该对比例用于说明参比的锂离子电池隔膜及其制备方法。
将实施例1的PE基膜本身作为本对比例的锂离子电池隔膜。经测试，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为150MPa和152MPa，针刺强度为0.501kgf，离子电导率为7.9mS/cm。此外，将该锂离子电池隔膜分别在120℃、140℃、160℃、180℃下烘烤1h，结果表明，在120℃下，横向和纵向热收缩率分别为：7％、75.2％，在140℃以上(包括140℃、160℃、180℃)，熔化为一团，收缩率在95％以上。
实施例2(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
将2kg Al2O3颗粒(平均粒径为400nm)、0.01kg聚丙烯酸钠(数均分子量为9000，购自广州市缘昌贸易有限公司)、0.024kg羧甲基纤维素钠(1重量％水溶液粘度为2500-3000mPa·s，购自新乡市和略利达电源材料有限公司，牌号为BTT-3000)与水混合均匀，使得到Al2O3的固含量为30重量％的混合物，将该混合物在6000rpm下搅拌1.5小时，之后加入0.02kg的3-缩水甘油醚氧基丙基三甲氧基硅烷继续搅拌1.5小时，然后加入0.1kg聚丙烯酸酯粘结剂(交联单体为N-羟甲基丙烯酰胺且其含量为4重量％，玻璃化转变温度为-20℃)，并在3000rpm下搅拌1.5小时，接着加入0.08kg十二烷基苯磺酸钠，之后在3000rpm下搅拌0.5小时，得到形成陶瓷层浆液。
将上述陶瓷层浆液涂覆在11μm厚的PE基膜(购自日本SK公司，牌号为BD1201，下同)的两侧表面上，烘干以在基膜的两侧表面上得到厚度均为1μm的陶瓷层，得到陶瓷隔膜C1，经检测，陶瓷隔膜C1两侧的陶瓷层在1μm厚度下的面密度均为2.11mg/cm2，透气性均为202s/100ml，剥离强度均为5.4N，120℃下的热稳定性均为A，160℃下的热稳定性均为A。
(2)制备耐热层：参照实施例1的方式在陶瓷隔膜C1的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F2，耐热层中的纤维平均直径为320nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为120MPa和125MPa，针刺强度为0.53kgf，离子电导率为7.7mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、2.3％、4％，纵向热收缩率分别为：0％、0％、2.4％、5％。
对比例2
该对比例用于说明参比的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备锂离子电池隔膜，不同的是，陶瓷层浆料的用量使得陶瓷层的厚度为4μm，且不包括形成耐热层的步骤，得到锂离子电池隔膜。经测试，该锂离子电池隔膜的横向拉伸强度和纵向拉伸强度分别为132MPa和143MPa，针刺强度为0.512kgf，离子电导率为6.9mS/cm。此外，将锂离子电池隔膜分别在120℃、140℃、160℃、180℃下烘烤1h，横向热收缩率分别为：0.3％、1％、6.5％、86％，纵向热收缩率分别为：0.5％、1.5％、5.5％、82.2％。
对比例3
该对比例用于说明参比的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备锂离子电池隔膜，不同的是，形成耐热层的方式为涂覆法，得到锂离子电池隔膜，其中，耐热层不具有多孔结构。经测试，该锂离子电池隔膜的横向拉伸强度和纵向拉伸强度分别为125MPa和130MPa，针刺强度为0.53kgf，离子电导率为0.05mS/cm。此外，将该锂离子电池隔膜分别在120℃、140℃、160℃、180℃下烘烤1h，横向热收缩率分别为：0％、0％、0.2％、2％，纵向热收缩率分别为：0％、0％、1.5％、2.4％。
实施例3(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：与实施例2相同，得到陶瓷隔膜C1。
(2)制备耐热层：将聚醚酰亚胺与Al2O3颗粒按重量比95：5(即100：5.26)加入N,N-二甲基吡咯烷酮(NMP)中，然后在70℃的水浴下磁力搅拌充分混合，形成浓度为20wt％的纺丝溶液。
按照实施例2的方法进行静电纺丝，得到形成有耐热层(单面厚度为3μm)的锂离子电池隔膜F3，耐热层中的纤维平均直径为258nm，耐热层的面密度为3.2g/m2，孔隙率为84％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为122MPa和126MPa，针刺强度为0.530kgf，离子电导率为7.7mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3.2％、4.5％，纵向热收缩率分别为：0％、0％、3.5％、4.8％。
实施例4(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：与实施例2相同，得到陶瓷隔膜C1。
(2)制备耐热层：将聚醚酰亚胺与Al2O3颗粒按重量比17：3(即100:17.6)加入N,N-二甲基吡咯烷酮(NMP)中，然后在70℃的水浴下磁力搅拌充分混合，形成浓度为10wt％的纺丝溶液。
按照实施例2的方法进行静电纺丝，得到形成有耐热层(厚度为3μm)的锂离子电池隔膜F4，耐热层中的纤维平均直径为420nm，耐热层的面密度为4.1g/m2，孔隙率为87％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为118MPa和122MPa，针刺强度为0.530kgf，离子电导率为6.9mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、1.2％、4％，纵向热收缩率分别为：0％、0％、2.3％、4.5％。
实施例5(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：与实施例2相同，得到陶瓷隔膜C1。
(2)制备耐热层：将聚醚酰亚胺与Al2O3颗粒按重量比2：1(即100:50)加入N,N-二甲基吡咯烷酮(NMP)中，然后在70℃的水浴下磁力搅拌充分混合，形成浓度为25wt％的纺丝溶液。
按照实施例2的方法进行静电纺丝，得到形成有耐热层(厚度为3μm)的锂离子电池隔膜F5，耐热层中的纤维平均直径为420nm，耐热层的面密度为4.1g/m2，孔隙率为87％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为114MPa和118MPa，针刺强度为0.530kgf，离子电导率为6.5mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、1.2％、3.5％，纵向热收缩率分别为：0％、0％、2.3％、4.2％。
实施例6(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
将2kg勃姆石(平均粒径为300nm)、0.016kg聚丙烯酸钠(数均分子量为9000，购自广州市缘昌贸易有限公司)、0.014kg羧甲基纳米纤维素钠(1重量％水溶液粘度为2500-3000mPaS，购自新乡市和略利达电源材料有限公司，牌号为BTT-3000)和水混合均匀，使得到勃姆石的固含量为50重量％的混合物，将该混合物在8000rpm下搅拌1.5小时，之 后加入0.01kg的3-缩水甘油醚氧基丙基三甲氧基硅烷继续搅拌1.5小时，然后加入0.12kg聚丙烯酸酯粘结剂(交联单体为N-羟甲基丙烯酰胺且其含量为3重量％，玻璃化转变温度为-40℃)，并在3000rpm下搅拌1.5小时，接着加入0.08kg十二烷基苯磺酸钠，并在3000rpm下搅拌1.5小时，得到形成陶瓷层浆液。
将上述陶瓷层浆液涂覆在11μm厚的PE基膜的一侧表面上，烘干以在基膜的一侧表面上得到厚度为2μm的陶瓷层，得到陶瓷隔膜C2，经检测，陶瓷隔膜C2的陶瓷层在1μm厚度下的面密度为2.02mg/cm2，透气性为198s/100ml，剥离强度为5.6N，120℃下的热稳定性为A，160℃下的热稳定性为A。
(2)制备耐热层：将聚醚醚酮(PEEK，商购自德国Evonik公司，熔点为334℃)、3g的TiO2颗粒(平均粒径为50μm)按重量比9:1(即100：11.1)加入N,N-二甲基吡咯烷酮(NMP)中，然后在70℃水浴下磁力搅拌充分混合，形成浓度为15wt％的纺丝溶液。
参照实施例2的方式在陶瓷隔膜C2的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F6，耐热层中的纤维平均直径为320nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为123MPa和129MPa，针刺强度为0.53kgf，离子电导率为7.7mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3.3％、5％，纵向热收缩率分别为：0％、0％、3.8％、6.1％。
实施例7(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
将2kg二氧化钛颗粒(平均粒径为500nm)、0.008kg聚丙烯酸钠(数均分子量为9000，购自广州市缘昌贸易有限公司)、0.03kg羧甲基纳米纤维素钠(1重量％水溶液粘度为2500-3000mPa·s，购自新乡市和略利达电源材料有限公司，牌号为BTT-3000)和水混合均匀，使得到二氧化钛的固含量为25重量％的混合物，将该混合物在4000转/min下搅拌1.5小时，之后加入0.024kg的3-缩水甘油基丙基三甲氧基硅烷继续搅拌1.5小时，然后加入0.08kg聚丙烯酸酯粘结剂(交联单体丙烯酸羟甲酯且其含量为5重量％，玻璃化温度为0℃)，并在3000转/min下搅拌1.5小时，接着加入0.08kg十二烷基苯磺酸钠，并在3000转/min下搅拌1.5小时，得到形成陶瓷层浆液。
将上述陶瓷层浆液涂覆在11μm厚的PE基膜的一侧表面上，烘干以在基膜的一侧表面上得到厚度均为3.5μm的陶瓷层，得到陶瓷隔膜C2，经检测，陶瓷隔膜C2的陶瓷层在1μm 厚度下的面密度为2.05mg/cm2，透气性为200s/100ml，剥离强度为5.7N，120℃下的热稳定性为A，160℃下的热稳定性为A。
(2)制备耐热层：
参照实施例2的方式在陶瓷隔膜C3的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F7，耐热层中的纤维平均直径为340nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为117MPa和121MPa，针刺强度为0.53kgf，离子电导率为7.6mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、2.5％、4.2％，纵向热收缩率分别为：0％、0％、2.5％、5.5％。
实施例8(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
按照实施例2的方法进行，不同的是，制备陶瓷层浆液时聚丙烯酸酯粘结剂的用量为0.06kg，且聚丙烯酸酯粘结剂中交联单体的含量为7重量％，得到陶瓷隔膜C4，经检测，陶瓷隔膜C4两侧的陶瓷层在1μm厚度下的面密度均为1.95mg/cm2，透气性均为208s/100ml，剥离强度均为4.3N，120℃下的热稳定性均为A，160℃下的热稳定性均为A。
(2)制备耐热层：
参照实施例2的方式在陶瓷隔膜C4的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F8，耐热层中的纤维平均直径为340nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为121MPa和125MPa，针刺强度为0.53kgf，离子电导率为7.5mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、2.8％、4.2％，纵向热收缩率分别为：0％、0％、2.6％、5.2％。
实施例9(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
(1)制备陶瓷隔膜：
按照实施例2的方法进行，不同的是，制备陶瓷层浆液时聚丙烯酸酯粘结剂的用量为0.12kg，聚丙烯酸酯粘结剂中交联单体的含量为5重量％，且不加入3-缩水甘油醚氧基丙基三甲氧基硅烷，得到陶瓷隔膜C5，经检测，陶瓷隔膜C5两侧的陶瓷层在1μm厚度下的面密度均为1.91mg/cm2，透气性均为212s/100ml，剥离强度均为4.5N，120℃下的热稳定性均 为A，160℃下的热稳定性均为A。
(2)制备耐热层：
参照实施例2的方式在陶瓷隔膜C5的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F9，耐热层中的纤维平均直径为340nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为119MPa和125MPa，针刺强度为0.53kgf，离子电导率为7.4mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3.6％、5.7％，纵向热收缩率分别为：0％、0％、3.1％、5.9％。
实施例10(耐热层-多孔基膜(陶瓷隔膜)-耐热层三层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
按照实施例2的方法进行，不同的是，制备陶瓷层浆液时聚丙烯酸酯粘结剂的用量为0.08kg，且聚丙烯酸酯粘结剂中交联单体的含量为2重量％，得到陶瓷隔膜C6，经检测，陶瓷隔膜C6两侧的陶瓷层在1μm厚度下的面密度均为2.00mg/cm2，透气性均为207s/100ml，剥离强度均为4.6N，120℃下的热稳定性均为A，160℃下的热稳定性均为A。
(2)制备耐热层：
参照实施例2的方式在陶瓷隔膜C6的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F10，耐热层中的纤维平均直径为340nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为120MPa和122MPa，针刺强度为0.54kgf，离子电导率为7.4mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3％、4.5％，纵向热收缩率分别为：0％、0％、2.8％、5.8％。
实施例11(多孔基膜(陶瓷隔膜)-耐热层两层结构的锂离子电池隔膜，其中，陶瓷层为非可选的陶瓷层)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
按照实施例2的方法进行，不同的是，三氧化二铝的平均粒径为700nm，得到陶瓷隔膜C7，经检测，陶瓷隔膜C7两侧的陶瓷层在1μm厚度下的面密度均为2.11mg/cm2，透气性均为205s/100ml，剥离强度均为4.7N，120℃下的热稳定性均为A，160℃下的热稳定性均 为A。
(2)制备耐热层：
参照实施例2的方式在陶瓷隔膜C7的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F11，耐热层中的纤维平均直径为340nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为121MPa和125MPa，针刺强度为0.53kgf，离子电导率为7.1mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3％、6％，纵向热收缩率分别为：0％、0％、3.5％、6.5％。
实施例12(多孔基膜(陶瓷隔膜)-耐热层两层结构的锂离子电池隔膜，其中，陶瓷层为非可选的陶瓷层)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
(1)制备陶瓷隔膜：
按照实施例2的方法进行，不同的是，三氧化二铝的平均粒径为250nm，得到陶瓷隔膜C8，经检测，陶瓷隔膜C8两侧的陶瓷层的面密度均为1.91mg/cm2，透气性均为208s/100ml，剥离强度均为4.8N，120℃下的热稳定性均为A，160℃下的热稳定性均为A。
(2)制备耐热层：
参照实施例2的方式在陶瓷隔膜C8的陶瓷层表面上进行静电纺丝，得到形成有耐热层的锂离子电池隔膜F11，耐热层中的纤维平均直径为340nm，耐热层的面密度为3.3g/m2，孔隙率为82％。此外，该锂离子电池隔膜的横向拉伸强度与纵向拉伸强度分别为120MPa和125MPa，针刺强度为0.52kgf，离子电导率为6.9mS/cm。将该锂离子电池隔膜分别在120℃、140℃、160℃和180℃下烘烤1h，横向热收缩率分别为：0％、0％、3.2％、6.2％，纵向热收缩率分别为：0％、0％、3.8％、6.8％。
实施例13(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将自交联型纯丙乳液(上海爱高化工有限公司，牌号为1040)、自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)和自交联型苯丙乳液(上海爱高化工有限公司，牌号为S601)以固含量9:1:10的质量比混合，并加入适量水，搅拌均匀配成总固含量为1重量％的粘结层浆料。
将上述粘结层浆料以喷涂的方法(温度为40℃)喷涂到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜(粘结层)的锂离子电池隔膜Sa1和PE基膜上的多孔自交联聚合物膜Sb1，其中多孔自交联聚合物膜的单面面密度均为0.1g/m2，单面厚度均为0.2μm，孔隙率均为62％且吸液率为263％，锂离子电池隔膜Sa1的离子电导率为8.28mS/cm。
实施例14(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将偏氟乙烯和六氟丙烯的共聚乳液(阿科玛，牌号为10278)、自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)和自交联型苯丙乳液(上海爱高化工有限公司，牌号为S601)以固含量12:4:4的质量比混合，并加入适量水，搅拌均匀配成总固含量为5重量％的粘结层浆料。
将上述粘结层浆料以丝网印刷的方法(温度为75℃)印到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa2和PE基膜上的多孔自交联聚合物膜Sb2，其中多孔自交联聚合物膜的单面面密度均为0.2g/m2，单面厚度均为0.4μm，孔隙率均为48％且吸液率为192％，锂离子电池隔膜Sa2的离子电导率为7.4mS/cm。
实施例15(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将自交联型纯丙乳液(上海爱高化工有限公司，牌号为1040)、偏氟乙烯和六氟丙烯的共聚乳液(阿科玛，牌号为10278)、自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)和自交联型苯丙乳液(上海爱高化工有限公司，牌号为S601)以固含量12:6:1:1的质量比混合，并加入适量水，搅拌均匀配成总固含量为10重量％的粘结层浆料。
将上述粘结层浆料以喷涂的方法(温度为58℃)喷涂到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa3和PE基膜上的多孔自交联聚合物膜Sb3，其中多孔自交联聚合物膜的单面面密度均为0.3g/m2，单面厚度均为0.3μm，孔隙率均为51％且吸液率为300％，锂离子电池隔膜Sa3的离子电导率为7mS/cm。
实施例16(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将自交联型纯丙乳液(上海爱高化工有限公司，牌号为1040)、偏氟乙烯和六氟丙烯的共聚乳液(阿科玛，牌号为10278)和自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)以固含量12.7:6.3:1的质量比混合，并加入适量水，搅拌均匀配成总固含量为1重量％的粘结层浆料。
将上述粘结层浆料以丝网印刷的方法(温度为40℃)印到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa4和PE基膜上的多孔自交联聚合物膜Sb4，其中多孔自交联聚合物膜的单面面密度均为0.1g/m2，单面厚度均为0.2μm，孔隙率均为53％且吸液率为311％，锂离子电池隔膜Sa4的离子电导率为7.46mS/cm。
实施例17(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将自交联型纯丙乳液(上海爱高化工有限公司，牌号为1040)、自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)和自交联型苯丙乳液(上海爱高化工有限公司，牌号为S601)以固含量6:1:13的质量比混合，并加入适量水，搅拌均匀配成总固含量为5重量％的粘结层浆料。
将上述粘结层浆料以喷涂的方法(温度为75℃)喷涂到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa5和PE基膜上的多孔自交联聚合物膜Sb5，其中多孔自交联聚合物膜的单面面密度均为0.2g/m2，单面厚度均为0.3μm，孔隙率均为46％且吸液率为220％，锂离子电池隔膜Sa5的离子电导率为7.15mS/cm。
实施例18(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将自交联型纯丙乳液(上海爱高化工有限公司，牌号为1040)、偏氟乙烯和六氟丙烯的 共聚乳液(阿科玛，牌号为10278)和自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)以固含量11.4:7.6:1的质量比混合，并加入适量水，搅拌均匀配成总固含量为10重量％的粘结层浆料。
将上述粘结层浆料以丝网印刷的方法(温度为75℃)印到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa6和PE基膜上的多孔自交联聚合物膜Sb6，其中多孔自交联聚合物膜的单面面密度均为0.3g/m2，单面厚度均为0.6μm，孔隙率均为55％且吸液率为287％，锂离子电池隔膜Sa6的离子电导率为7.81mS/cm。
实施例19(粘结层-多孔基膜(陶瓷隔膜)-耐热层-粘结层四层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将自交联型纯丙乳液(上海爱高化工有限公司，牌号为1040)、偏氟乙烯和六氟丙烯的共聚乳液(阿科玛，牌号为10278)和自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)以固含量9.5:9.5:1的质量比混合，并加入适量水，搅拌均匀配成总固含量为1重量％的粘结层浆料。
将上述粘结层浆料以喷涂的方法(温度为40℃)喷涂到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa7和PE基膜上的多孔自交联聚合物膜Sb7，其中多孔自交联聚合物膜的单面面密度均为0.1g/m2，单面厚度均为0.2μm，孔隙率均为59％且吸液率为252％，锂离子电池隔膜Sa7的离子电导率为7.95mS/cm。
实施例20(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将偏氟乙烯和六氟丙烯的共聚乳液(阿科玛，牌号为10278)和自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)以固含量19:1的质量比混合，并加入适量水，搅拌均匀配成总固含量为5重量％的粘结层浆料。
将上述粘结层浆料以丝网印刷的方法(温度为75℃)印到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电 池隔膜Sa8和PE基膜上的多孔自交联聚合物膜Sb8，其中多孔自交联聚合物膜的单面面密度均为0.2g/m2，单面厚度均为0.3μm，孔隙率均为53％且吸液率为76％，锂离子电池隔膜Sa8的离子电导率为7.58mS/cm。
实施例21(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
将偏氟乙烯和六氟丙烯的共聚乳液(阿科玛，牌号为10278)和自交联型纯丙乳液(上海爱高化工有限公司，牌号为1005)以固含量18:2的质量比混合，并加入适量水，搅拌均匀配成总固含量为10重量％的粘结层浆料。
将上述粘结层浆料以喷涂的方法(温度为58℃)喷涂到上述复合膜的两侧表面上以及PE基膜的一侧表面上，再在50℃下烘干，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa9和PE基膜上的多孔自交联聚合物膜Sb9，其中多孔自交联聚合物膜的单面面密度均为0.3g/m2，单面厚度均为0.6μm，孔隙率均为47％且吸液率为112％，锂离子电池隔膜Sa9的离子电导率为7.28mS/cm。
实施例22(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
按照实施例13的方法形成制备粘结层浆液，不同的是，该粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液(上海爱高化工有限公司，牌号为A1030，聚丙烯腈链段占15重量％，聚丙烯酸丁酯链段占30重量％，聚甲基丙烯酸甲酯链段占45重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝28℃，固含量为50重量％)，且A1030的固含量与1040和1005的总固含量的重量比为1：1。
将该粘结层浆料按照实施例13的方法形成粘结层，得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa10和PE基膜上的多孔自交联聚合物膜Sb10，其中单面多孔自交联聚合物涂层的面密度均为0.1g/m2，厚度均为0.2μm，孔隙率均为48％且吸液率均为293％，锂离子电池隔膜Sa10的离子电导率为7.68mS/cm。
实施例23(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
按照实施例13的方法形成制备粘结层浆液，不同的是，该粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液(上海爱高化工有限公司，牌号为A1030，聚丙烯腈链段占15重量％，聚丙烯酸丁酯链段占30重量％，聚甲基丙烯酸甲酯链段占45重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝28℃，固含量为50重量％)，且A1030的固含量与1040和1005的总固含量的重量比为1：1。
将该粘结层浆料按照实施例13的方法形成粘结层，得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa11和PE基膜上的多孔自交联聚合物膜Sb11，其中单面多孔自交联聚合物涂层的面密度均为0.1g/m2，厚度均为0.2μm，孔隙率均为50％且吸液率均为214％，锂离子电池隔膜Sa11的离子电导率为7.18mS/cm。
实施例24(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
按照实施例13的方法形成制备粘结层浆液，不同的是，该粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液(上海爱高化工有限公司，牌号为A1030，聚丙烯腈链段占15重量％，聚丙烯酸丁酯链段占30重量％，聚甲基丙烯酸甲酯链段占45重量％，聚丙烯酸乙酯链段占5重量％，聚丙烯酸链段占5重量％，玻璃化转变温度Tg＝28℃，固含量为50重量％)，且A1030的固含量与1040和1005的总固含量的重量比为1：1。
将该粘结层浆料按照实施例13的方法形成粘结层，得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa12和PE基膜上的多孔自交联聚合物膜Sb12，其中单面多孔自交联聚合物涂层的面密度均为0.1g/m2，厚度均为0.2μm，孔隙率均为46％且吸液率均为182％，锂离子电池隔膜Sa12的离子电导率为7.27mS/cm。
实施例25(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例用于说明本公开提供的锂离子电池隔膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
按照实施例14的方法形成制备粘结层浆液，不同的是，将自交联型纯丙乳液1005采用相同重量份的的自交联型纯丙乳液1020代替。
将该粘结层浆料按照实施例12的方法形成粘结层，得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa13和PE基膜上的多孔自交联聚合物膜Sb13，其中单面多孔自交联聚合物涂层的面密度均为0.2g/m2，厚度均为0.4μm，孔隙率均为47％且吸液率均为160％，锂离子电池隔膜Sa13的离子电导率为6.98mS/cm。
粘结层实施对照例(粘结层-耐热层-多孔基膜(陶瓷隔膜)-耐热层-粘结层五层结构的锂离子电池隔膜)
该实施例为对比实施例，用于说明粘结层为非可选的粘结层时的聚合物复合膜及其制备方法。
按照实施例2的方法制备陶瓷隔膜和耐热层，得到复合膜。
按照实施例13的方法形成制备粘结层浆液，不同的是，形成粘结层的方法为刮涂法，分别得到包括多孔自交联聚合物膜的锂离子电池隔膜Sa14和PE基膜上的多孔自交联聚合物膜Sb14，其中单面多孔自交联聚合物膜(粘结层)的面密度为1g/m2，厚度为2μm。经检测前述制备的多孔自交联聚合物膜Sb14的孔隙率为0％，吸液率为156％，导电率为5.25mS/cm。经测试前述制备的锂离子电池隔膜Sa14的离子电导率为5.05mS/cm。
以上详细描述了本公开的实施方式，但是，本公开并不限于上述实施方式中的具体细节，在本公开的技术构思范围内，可以对本公开的技术方案进行多种简单变型，这些简单变型均属于本公开的保护范围。
另外需要说明的是，在上述具体实施方式中所描述的各个具体技术特征，在不矛盾的情况下，可以通过任何合适的方式进行组合。为了避免不必要的重复，本公开对各种可能的组合方式不再另行说明。
此外，本公开的各种不同的实施方式之间也可以进行任意组合，只要其不违背本公开的思想，其同样应当视为本公开所公开的内容。

Claims (38)

  1. 一种锂离子电池隔膜，包括
    多孔基膜，和覆盖在所述多孔基膜的至少一侧表面上的耐热层；所述耐热层含有耐高温聚合物以及无机纳米颗粒，且所述耐热层具有纤维网络状结构。
  2. 根据权利要求1所述的锂离子电池隔膜，其中，所述耐高温聚合物与无机纳米材料的重量比为100：(3-50)；可选为100：(5-18)。
  3. 根据权利要求1所述的锂离子电池隔膜，其中，所述耐热层由耐高温聚合物和无机纳米材料组成，所述耐热层中的纤维平均直径为100-2000nm。
  4. 根据权利要求1所述的锂离子电池隔膜，其中，所述耐热层的孔隙率为80％以上，所述耐热层的单面面密度为0.2-15g/m2。
  5. 根据权利要求1所述的锂离子电池隔膜，其中，所述耐热层通过将含有耐高温聚合物和无机纳米颗粒的纺丝溶液经静电纺丝而形成。
  6. 根据权利要求1所述的锂离子电池隔膜，其中，所述耐高温聚合物的熔点不低于180℃，可选为200-600℃。
  7. 根据权利要求1所述的锂离子电池隔膜，其中，所述耐高温聚合物为聚醚酰亚胺、聚酰亚胺、聚醚醚酮、聚醚砜、聚酰胺酰亚胺、聚酰胺酸和聚乙烯吡咯烷酮中的至少一种；可选地，所述耐高温聚合物为聚醚酰亚胺和聚醚醚酮中的至少一种。
  8. 根据权利要求1所述的锂离子电池隔膜，其中，所述无机纳米颗粒的平均粒径为50nm-3μm；
    可选地，所述无机纳米颗粒为Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2、CNT、BN、SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α–V2O5、PbTiO3、TiB2、CaSiO3、分子筛、粘土和高岭土中的至少一种。
  9. 根据权利要求1所述的锂离子电池隔膜，其中，所述多孔基膜为聚合物隔膜或陶瓷隔膜，所述陶瓷隔膜包括聚合物隔膜和位于所述聚合物隔膜至少一侧表面的陶瓷层；
    可选地，所述多孔基膜为陶瓷隔膜，所述耐热层位于所述陶瓷隔膜中形成有陶瓷层一侧的表面上；
    可选地，所述聚合物隔膜为聚烯烃隔膜。
  10. 根据权利要求9所述的锂离子电池隔膜，其中，所述陶瓷层含有陶瓷颗粒和粘结剂，且所述陶瓷层在1μm厚度下的面密度ρ满足1.8mg/cm2＜ρ≤2.7mg/cm2，可选地满足1.85mg/cm2≤ρ≤2.65mg/cm2，可选地满足1.9mg/cm2≤ρ≤2.6mg/cm2；
    可选地，所述陶瓷颗粒选自Al2O3、SiO2、BaSO4、BaO、TiO2、CuO、MgO、Mg(OH)2、LiAlO2、ZrO2、CNT、BN、SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α-V2O5、PbTiO3、TiB2、CaSiO3、分子筛、粘土、勃姆石和高岭土中的至少一种，可选地所述陶瓷颗粒的平均粒径为200-800nm；
    可选地，所述粘结剂为玻璃化转变温度满足-40℃至0℃的聚丙烯酸酯；
    可选地，所述陶瓷层的单面厚度为1-5μm。
  11. 根据权利要求10所述的锂离子电池隔膜，其中，在所述陶瓷层中，相对于100重量份的所述陶瓷颗粒，所述粘结剂的含量为2-8重量份；
    可选地，在所述陶瓷层中，相对于100重量份的所述陶瓷颗粒，还包括0.3-1重量份的分散剂、0.5-1.8重量份的增稠剂、以及0-1.5重量份的表面处理剂，且所述分散剂的数均分子量在5万以下；
    可选地，在所述陶瓷层中，相对于100重量份的所述陶瓷颗粒，所述粘结剂的含量为4-6重量份，所述分散剂的含量为0.4-0.8重量份，所述增稠剂的含量为0.7-1.5重量份，所述表面处理剂的含量为0.5-1.2重量份；
    可选地，所述分散剂为聚丙烯酸盐、聚乙二醇醚、硅酸盐类化合物、磷酸盐类化合物和古尔胶中的至少一种；
    可选地，所述增稠剂为聚丙烯酸盐、丙烯酸共聚物、聚乙烯吡咯烷酮、纤维素类化合物和聚丙烯酰胺中的至少一种；
    可选地，所述表面处理剂为3-缩水甘油醚氧基丙基三甲氧基硅烷和/或3-缩水甘油醚氧基丙基三乙氧基硅烷。
  12. 根据权利要求1至11中任一项所述的锂离子电池隔膜，其中，所述锂离子电池隔膜还包括粘结层，所述粘结层形成于所述锂离子电池隔膜的至少一侧表面的最外侧，所述粘结层含有丙烯酸酯类交联聚合物以及苯乙烯-丙烯酸酯类交联共聚物和/或偏氟乙烯-六氟丙烯共聚物，且所述粘结层的孔隙率为40-65％。
  13. 根据权利要求12所述的锂离子电池隔膜，其中，所述丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至60℃，所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为-30℃至50℃，所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-65℃至-40℃。
  14. 根据权利要求12所述的锂离子电池隔膜，其中，
    所述粘结层含有所述丙烯酸酯类交联聚合物和所述苯乙烯-丙烯酸酯类交联共聚物且不含有所述偏氟乙烯-六氟丙烯共聚物，所述丙烯酸酯类交联聚合物与所述苯乙烯-丙烯酸酯类交联共聚物的重量比为1：0.05至1：2；或者，
    所述粘结层含有所述丙烯酸酯类交联聚合物和所述偏氟乙烯-六氟丙烯共聚物且不含有所述苯乙烯-丙烯酸酯类交联共聚物，所述丙烯酸酯类交联聚合物与所述偏氟乙烯-六氟丙烯共聚物的重量比为1：0.3至1：25；或者，
    所述粘结层含有所述丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物和所述偏氟乙烯-六氟丙烯共聚物，所述丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物与所述偏氟乙烯-六氟丙烯共聚物的重量比为1：(0.01-2)：(0.3-5)。
  15. 根据权利要求12所述的锂离子电池隔膜，其中，
    所述丙烯酸酯类交联聚合物为第一丙烯酸酯类交联聚合物与第二丙烯酸酯类交联聚合物和/或第三丙烯酸酯类交联聚合物的混合物，或为所述第二丙烯酸酯类交联聚合物，或为所述第三丙烯酸酯类交联聚合物；
    所述第一丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述第一丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二丙烯酸酯类交联聚合物的 玻璃化转变温度为-20℃至-5℃，所述第三丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃；
    所述苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃；
    所述偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段；所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
  16. 根据权利要求12所述的锂离子电池隔膜，其中，所述粘结层含有第一丙烯酸酯类交联聚合物、第二丙烯酸酯类交联聚合物和所述苯乙烯-丙烯酸酯类交联共聚物且不含有所述偏氟乙烯-六氟丙烯共聚物，且所述第一丙烯酸酯类交联聚合物、所述第二丙烯酸酯类交联聚合物与所述苯乙烯-丙烯酸酯类交联共聚物的重量比为(5-10)：1：(10-13)；或者，
    所述粘结层含有所述第一丙烯酸酯类交联聚合物、所述第二丙烯酸酯类交联聚合物和所述偏氟乙烯-六氟丙烯共聚物且不含有所述苯乙烯-丙烯酸酯类交联共聚物，所述第一丙烯酸酯类交联聚合物、所述第二丙烯酸酯类交联聚合物与所述偏氟乙烯-六氟丙烯共聚物的重量比为(5-15)：1：(5-12)；或者，
    所述粘结层含有所述第二丙烯酸酯类交联聚合物和所述偏氟乙烯-六氟丙烯共聚物且不含有所述苯乙烯-丙烯酸酯类交联共聚物，所述第二丙烯酸酯类交联聚合物与所述偏氟乙烯-六氟丙烯共聚物的重量比为1：5至1：20；或者，
    所述粘结层含有所述第二丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物和所述偏氟乙烯-六氟丙烯共聚物，所述第二丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物与所述偏氟乙烯-六氟丙烯共聚物的重量比为1：(0.5-2)：(1-5)；或者，
    所述粘结层含有第三丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物和所述偏氟乙烯-六氟丙烯共聚物，所述第三丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物与所述偏氟乙烯-六氟丙烯共聚物的重量比为1：(0.5-2)：(1-5)；或者，
    所述粘结层含有所述第一丙烯酸酯类交联聚合物、所述第二丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物和所述偏氟乙烯-六氟丙烯共聚物，所述第一丙烯酸酯类交联聚合物、所述第二丙烯酸酯类交联聚合物、所述苯乙烯-丙烯酸酯类交联共聚物与所述偏氟乙烯-六氟丙烯共聚物的重量比为(10-15)：1：(0.5-2)：(5-10)；
    其中，所述第一丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10 重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段；所述第一丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃，所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃，所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
  17. 根据权利要求12所述的锂离子电池隔膜，其中，所述粘结层中还含有丙烯腈-丙烯酸酯共聚物、氯丙共聚物和丁苯共聚物中的至少一种；
    可选地，当所述粘结层中还含有丙烯腈-丙烯酸酯共聚物时，所述丙烯腈-丙烯酸酯共聚物与所述丙烯酸酯类交联聚合物的重量比为0.05：1至2：1；
    可选地，当所述粘结层中还含有氯丙共聚物时，所述氯丙共聚物与所述丙烯酸酯类交联聚合物的重量比为0.15：1至7：1；
    可选地，当所述粘结层中还含有丁苯共聚物时，所述丁苯共聚物与所述丙烯酸酯类交联聚合物的重量比为0.05：1至2：1。
  18. 根据权利要求12所述的锂离子电池隔膜，其中，所述粘结层的单面面密度为0.05-0.9mg/cm2；所述粘结层的单面厚度为0.1-1μm。
  19. 一种锂离子电池隔膜的制备方法，该方法包括如下步骤：
    S1、提供多孔基膜；
    S2、配制含有耐高温聚合物和无机纳米颗粒的纺丝溶液，并将所述纺丝溶液通过静电纺丝在所述多孔基膜的至少一侧表面上形成耐热层；
    可选地，所述纺丝溶液中耐高温聚合物与无机纳米材料的重量比为100:(3-50)；可选为100：(5-18)。
  20. 根据权利要求19所述的制备方法，其中，
    所述静电纺丝法包括有针头纺丝法和无针头纺丝法；
    当所述静电纺丝法为有针头纺丝法时，纺丝的条件包括：纺丝溶液的流速为0.3-5mL/h，纺丝温度为25-70℃，纺丝湿度为2％-60％，纺丝电压为5-25kV，滚筒的转速为100-6000rpm；
    当所述静电纺丝法为无针头纺丝法时，纺丝的条件包括：温度为25-70℃，湿度为2％-60％，液池移动速度为0-2000mm/sec，基材移动速度为0-20000mm/min，正极电压为0-150kV，负极电压为-50至0kV，电压差为10-100kV。
  21. 根据权利要求19所述的制备方法，其中，所述耐高温聚合物的熔点不低于180℃，可选为200-600℃。
  22. 根据权利要求19所述的制备方法，其中，所述耐高温聚合物为聚醚酰亚胺、聚酰亚胺、共聚醚醚酮、聚醚醚酮、聚醚砜、聚酰胺酰亚胺、聚酰胺酸和聚乙烯吡咯烷酮中的至少一种。
  23. 根据权利要求19所述的制备方法，其中，所述无机纳米颗粒的平均粒径为50nm-3μm；
    可选地，所述无机纳米颗粒为Al2O3、SiO2、BaSO4、TiO2、CuO、MgO、LiAlO2、ZrO2、CNT、BN、SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α–V2O5、PbTiO3、TiB2、CaSiO3、分子筛、粘土和高岭土中的至少一种。
  24. 根据权利要求19所述的制备方法，还包括在静电纺丝之后，在50-120℃、0.5-15MPa下进行压膜的步骤。
  25. 根据权利要求19至24中任一项所述的制备方法，其中，所述多孔基膜为陶瓷隔膜，所述陶瓷隔膜包括聚合物隔膜和位于所述聚合物隔膜表面的陶瓷层；所述耐热层形成在所述陶瓷隔膜中所述陶瓷层的表面上。
  26. 根据权利要求25所述的制备方法，其中，所述陶瓷隔膜的制备方法包括：
    S11、提供聚合物隔膜；
    S12、将陶瓷颗粒、粘结剂、分散剂和增稠剂按照重量比100：(2-8)：(0.3-1)：(0.5-1.8)的比例搅拌混合得到陶瓷层浆液，并将所述陶瓷层浆液涂覆于所述聚合物隔膜的至少一侧表面上，烘干得到所述陶瓷层；所述分散剂的数均分子量为5万以下；
    可选地，步骤S12中，所述搅拌的转速为3000-10000rpm，可选为3000-9000rpm；
    可选地，步骤S12中，将所述陶瓷颗粒、所述粘结剂、所述分散剂和所述增稠剂按照重量比100：(4-6)：(0.4-0.8)：(0.7-1.5)的比例搅拌混合。
  27. 根据权利要求26所述的制备方法，其中，步骤S12中，
    所述陶瓷颗粒选自选自Al2O3、SiO2、BaSO4、BaO、TiO2、CuO、MgO、Mg(OH)2、LiAlO2、ZrO2、CNT、BN、SiC、Si3N4、WC、BC、AlN、Fe2O3、BaTiO3、MoS2、α–V2O5、PbTiO3、TiB2、CaSiO3、分子筛、粘土、勃姆石和高岭土中的至少一种，可选地，所述陶瓷颗粒的平均粒径为200-800nm；
    所述粘结剂为玻璃化转变温度满足-40℃至0℃的聚丙烯酸酯；
    所述分散剂为聚丙烯酸盐、聚乙二醇醚、硅酸盐类化合物、磷酸盐类化合物和古尔胶中的至少一种；
    所述增稠剂为聚丙烯酸盐、丙烯酸共聚物、聚乙烯吡咯烷酮、纤维素类化合物和聚丙烯酰胺中的至少一种。
  28. 根据权利要求26所述的制备方法，其中，步骤S12中混合得到的所述陶瓷层浆液中还含有表面处理剂，所述表面处理剂为3-缩水甘油醚氧基丙基三甲氧基硅烷和/或3-缩水甘油醚氧基丙基三乙氧基硅烷；
    可选地，相对于100重量份的所述陶瓷颗粒，所述表面处理剂的用量为1.5重量份以下，可选为0.5-1.2重量份。
  29. 根据权利要求19至28中任一项所述的制备方法，还包括：S3、在由步骤S2所得到的复合膜的至少一侧表面上形成粘结层。
  30. 根据权利要求29所述的制备方法，其中，步骤S3包括：
    将含有自交联型纯丙乳液以及自交联型苯丙乳液和/或偏氟乙烯和六氟丙烯的共聚乳液的粘结层浆料附着在由步骤S2所得到的复合膜的至少一侧表面上，并干燥以形成孔隙率为40-65％的粘结层；
    可选地，所述自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至60℃，所述自交联型苯丙乳液中的苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为-30℃至50℃，所述偏氟乙烯和六氟丙烯的共聚乳液中的偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-65℃至-40℃。
  31. 根据权利要求30所述的制备方法，其中，步骤S3中，
    所述粘结层浆料含有所述自交联型纯丙乳液和所述自交联型苯丙乳液且不含有所述偏氟乙烯和六氟丙烯的共聚乳液，所述自交联型纯丙乳液与所述自交联型苯丙乳液的固含量的重量比为1：0.05至1：2；或者，
    所述粘结层浆料含有所述自交联型纯丙乳液和所述偏氟乙烯和六氟丙烯的共聚乳液且不含有所述自交联型苯丙乳液，所述自交联型纯丙乳液与所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：0.3至1：25；或者，
    所述粘结层浆料含有所述自交联型纯丙乳液、所述自交联型苯丙乳液、所述偏氟乙烯和六氟丙烯的共聚乳液，所述自交联型纯丙乳液、所述自交联型苯丙乳液、所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：(0.01-2)：(0.3-5)。
  32. 根据权利要求30所述的制备方法，其中，所述自交联型纯丙乳液为第一自交联型纯丙乳液与第二自交联型纯丙乳液和/或第三自交联型纯丙乳液的混合物，或为第二自交联型纯丙乳液或为第三自交联型纯丙乳液；所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃；
    所述自交联型苯丙乳液中的所述苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段；所述苯乙烯-丙烯酸酯类交联共 聚物的玻璃化转变温度为15-30℃；
    所述偏氟乙烯和六氟丙烯的共聚乳液中的所述偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段；所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
  33. 根据权利要求30所述的制备方法，其中，
    所述粘结层浆料含有第一自交联型纯丙乳液、第二自交联型纯丙乳液和所述自交联型苯丙乳液且不含有所述偏氟乙烯和六氟丙烯的共聚乳液，所述第一自交联型纯丙乳液、所述第二自交联型纯丙乳液与所述自交联型苯丙乳液的固含量的重量比为(5-10)：1：(10-13)；或者，
    所述粘结层浆料含有所述第一自交联型纯丙乳液、所述第二自交联型纯丙乳液以及所述偏氟乙烯和六氟丙烯的共聚乳液且不含有所述自交联型苯丙乳液，所述第一自交联型纯丙乳液、所述第二自交联型纯丙乳液与所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为(5-15)：1：(5-12)；或者，
    所述粘结层浆料含有所述第二自交联型纯丙乳液和所述偏氟乙烯和六氟丙烯的共聚乳液且不含有所述自交联型苯丙乳液，所述第二自交联型纯丙乳液与所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：5至1：20；或者，
    所述粘结层浆料含有所述第二自交联型纯丙乳液、所述自交联型苯丙乳液以及所述偏氟乙烯和六氟丙烯的共聚乳液，所述第二自交联型纯丙乳液、所述自交联型苯丙乳液与所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：(0.5-2)：(1-5)；或者，
    所述粘结层浆料含有第三自交联型纯丙乳液、所述自交联型苯丙乳液以及所述偏氟乙烯和六氟丙烯的共聚乳液，所述第三自交联型纯丙乳液、所述自交联型苯丙乳液与所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为1：(0.5-2)：(1-5)；或者，
    所述粘结层浆料含有所述第一自交联型纯丙乳液、所述第二自交联型纯丙乳液、所述自交联型苯丙乳液以及所述偏氟乙烯和六氟丙烯的共聚乳液，所述第一自交联型纯丙乳液、所述第二自交联型纯丙乳液、所述自交联型苯丙乳液与所述偏氟乙烯和六氟丙烯的共聚乳液的固含量的重量比为(10-15)：1：(0.5-2)：(5-10)；
    所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有70-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、10-20重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有30-40重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、50-60重量％的聚丙烯酸 丁酯链段和2-10重量％的聚丙烯酸链段，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物含有50-80重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、15-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述自交联型苯丙乳液中的苯乙烯-丙烯酸酯类交联共聚物含有40-50重量％的聚苯乙烯链段、5-15重量％的聚甲基丙烯酸甲酯链段、2-10重量％的聚丙烯酸乙酯链段、30-40重量％的聚丙烯酸丁酯链段和2-10重量％的聚丙烯酸链段，所述偏氟乙烯和六氟丙烯的共聚乳液中的偏氟乙烯-六氟丙烯共聚物含有80-98重量％的聚偏氟乙烯链段和2-20重量％的聚六氟丙烯链段；所述第一自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为50℃-60℃，所述第二自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为-20℃至-5℃，所述第三自交联型纯丙乳液中的丙烯酸酯类交联聚合物的玻璃化转变温度为30℃-50℃，所述苯乙烯-丙烯酸酯类交联共聚物的玻璃化转变温度为15-30℃，所述偏氟乙烯-六氟丙烯共聚物的玻璃化转变温度为-60℃至-40℃。
  34. 根据权利要求30所述的制备方法，其中，所述粘结层浆料中还含有丙烯腈和丙烯酸酯的共聚乳液、氯丙乳液和丁苯胶乳中的至少一种；
    可选地，当所述粘结层浆料中还含有所述丙烯腈和丙烯酸酯的共聚乳液时，所述丙烯腈和丙烯酸酯的共聚乳液与所述自交联型纯丙乳液的固含量的重量比为0.05：1至2：1；
    可选地，当所述粘结层浆料中还含有所述氯丙乳液时，所述氯丙乳液与所述自交联型纯丙乳液的固含量的重量比为0.15：1至7：1；
    可选地，当所述粘结层浆料中还含有所述丁苯胶乳时，所述丁苯胶乳与所述自交联型纯丙乳液的固含量的重量比为0.05：1至2：1。
  35. 根据权利要求30所述的制备方法，其中，所述附着的方法为喷涂法和/或丝网印刷法；所述喷涂法和丝网印刷法的操作温度各自独立地为30-80℃；所述干燥的温度为30-80℃。
  36. 由权利要求19至35中任一项所述的方法制备得到的锂离子电池隔膜。
  37. 一种锂离子电池，所述锂离子电池包括正极、负极、电解质和隔膜，其中所述隔膜为权利要求1至18和36中任一项所述的陶瓷隔膜。
  38. 一种锂离子电池的制备方法，该方法包括将正极、隔膜和负极依次层叠或卷绕成极芯，然后往所述极芯中注入电解液并封口，其中所述隔膜为权利要求1至18和36中任意一项所述的锂离子电池隔膜
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EP3490031A4 (en) 2019-05-29
CN107799696A (zh) 2018-03-13
EP3490031A1 (en) 2019-05-29
KR20190042576A (ko) 2019-04-24

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