WO2025112293A1 - 隔离膜及其制备方法、电池和用电装置 - Google Patents

隔离膜及其制备方法、电池和用电装置 Download PDF

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Publication number
WO2025112293A1
WO2025112293A1 PCT/CN2024/092042 CN2024092042W WO2025112293A1 WO 2025112293 A1 WO2025112293 A1 WO 2025112293A1 CN 2024092042 W CN2024092042 W CN 2024092042W WO 2025112293 A1 WO2025112293 A1 WO 2025112293A1
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coating
base film
fluorine
lithium
present application
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English (en)
French (fr)
Inventor
刘锋
范玉磊
钟韡
葛销明
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Contemporary Amperex Technology Co Ltd
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Contemporary Amperex Technology Co Ltd
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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
    • 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
    • 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
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application belongs to the field of batteries, and specifically, relates to an isolation membrane and a preparation method thereof, a battery and an electrical device.
  • batteries are widely used in various fields. Take lithium-ion batteries as an example. They are green, environmentally friendly, high-energy, and low-carbon. They are not only used in energy storage power systems such as hydropower, thermal, wind, and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, and ships, as well as military equipment and aerospace and other fields. With the development of the current society, people's requirements for batteries are getting higher and higher.
  • the present application provides an isolation membrane, aiming to inhibit dendrites from piercing the isolation membrane.
  • an isolation film which comprises:
  • a base film and a coating wherein the coating comprises a fluorine-containing carbon material, and a solid electrolyte and/or a metal oxide, wherein the coating is arranged on at least one of the two sides of the base film along its thickness direction, and/or the coating is arranged in the middle of the base film along its thickness direction.
  • the isolation membrane of the present application has the following beneficial effects: it can inhibit the growth of dendrites and improve the isolation membrane's resistance to dendrite penetration, thereby reducing the risk of dendrites penetrating the isolation membrane and short circuiting within the battery.
  • the general formula of the fluorine-containing carbon material is CFx, 0.85 ⁇ x ⁇ 1.5, and optionally, 1 ⁇ x ⁇ 1.25, which is beneficial to further improve the performance of the battery.
  • the fluorine-containing carbon material includes one or more of fluorinated graphite, fluorinated carbon black, fluorinated carbon, fluorinated graphene, fluorinated carbon nanotubes, and fluorinated carbon fibers, thereby reducing the risk of the isolation membrane being pierced by dendrites.
  • the particle size of the fluorine-containing carbon material is 50 nm to 5 ⁇ m, and can be 50 nm to 1 ⁇ m. Meeting the given conditions is beneficial to improving the uniformity and adhesion of the coating, and is also beneficial to making the isolation membrane have better ion transmission capacity.
  • the volume particle size Dv50 of the fluorine-containing carbon material is 50 nm to 1000 nm, and can be 50 nm to 500 nm, which is conducive to further taking into account the uniformity of the coating and the ion transmission capacity of the isolation membrane.
  • the volume particle size Dv90 of the fluorine-containing material is ⁇ 3 ⁇ m, and can be ⁇ 1 ⁇ m, which is conducive to further taking into account the uniformity of the coating and the ion transmission capacity of the isolation membrane.
  • the surface density of the coating is 3.5 g/m 2 to 15 g/m 2 ; and/or the surface density of the fluorocarbon material in the coating is 2 g/m 2 to 14.5 g/m 2 .
  • the total mass percentage of the solid electrolyte and/or the metal oxide is ⁇ 70%, and can be 20% to 50%. This is conducive to further reducing the isolation membrane from being pierced by dendrites. risks while taking into account good ion transmission capabilities.
  • the wetting angles of the solid electrolyte and the metal oxide are independently ⁇ 15°, thereby improving the affinity between the isolation membrane and the highly polar electrolyte and the problem that the isolation membrane is easily pierced by dendrites.
  • the ionic conductivity of the solid electrolyte at 25° C. is ⁇ 10 ⁇ 4 S/cm. Meeting the given conditions can further improve the ion transport capability of the isolation membrane and inhibit the growth of lithium dendrites.
  • the lithium insertion capacity of the metal oxide is ⁇ 600 mAh/g, which is beneficial to further improve the puncture resistance of the isolation film and inhibit the growth of lithium dendrites.
  • the solid electrolyte includes one or more of an oxide electrolyte, a sulfide electrolyte, and an acid salt electrolyte, and optionally includes one or more of Li 7 La 3 Zr 2 O 12 , Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , LiTi 2 (PO 4 ) 3 , Li 3 PS 4 , Li 10 GeP 2 S 12 , and Li 6 PS 5 Cl. This is beneficial to further improve the puncture resistance of the isolation membrane and inhibit the growth of lithium dendrites.
  • the metal oxide includes one or more of Fe oxide, Sn oxide, Ti oxide, Cu oxide, Mn oxide, Al oxide, Ge oxide, Zr oxide, and Zn oxide, thereby effectively inhibiting the formation of dendrites.
  • the coating further comprises: a lithium supplement material, which is also helpful in compensating for the slight capacity loss that may be caused by the consumption of lithium by the coating.
  • the mass percentage of the lithium supplementing material is ⁇ 25% based on the mass of the fluorine-containing carbon material. This is beneficial for compensating for the slight capacity loss of the battery caused by the consumption of lithium by the coating, and also for avoiding the risk of weakening the inhibitory effect of the coating on lithium dendrite growth caused by excessive use of the lithium supplementing material.
  • the lithium supplement material includes one or more of LiF, Li 3 N, M-coated Li 2 O, and Li x Si-coated Li 2 O
  • M includes one or more of Fe, Co, Ni, and Mn
  • x ranges from 0.5 to 3.75, thereby achieving a better lithium supplement effect at a lower dosage.
  • the coating further includes: one or more of a binder, a dispersant, and a thickener.
  • the coating satisfies one or more of the following conditions: (I) the mass percentage of the binder is 0.5% to 5%; (II) the mass percentage of the dispersant is ⁇ 2%; (III) the mass percentage of the thickener is ⁇ 2%.
  • the coating satisfies one or more of the following conditions: (i) the mass percentage of the binder is 1% to 3%; (ii) the mass percentage of the dispersant is 1% to 1.5%; (iii) the mass percentage of the thickener is 1% to 1.5%.
  • the thickness of a single layer of the coating is 1.5 ⁇ m to 3.5 ⁇ m, and can be 1.5 ⁇ m to 3 ⁇ m. This can not only improve the ability of the isolation film to resist dendrite puncture, but also reduce the risk of increased reversible capacity loss of the battery and decreased battery energy density caused by excessive coating thickness.
  • the total thickness of the coating is ⁇ 5 ⁇ m, which is helpful to further reduce the risk of increased battery reversible capacity loss and decreased battery energy density caused by excessive coating thickness.
  • the ratio of the total thickness of the coating to the thickness of the base film is 1:(2.5-10). Meeting the given conditions can take into account both the dendrite puncture resistance of the isolation film and the energy density of the battery.
  • the coating is only provided on at least one of the two sides of the base film along the thickness direction thereof, the two sides of the base film along the thickness direction thereof are respectively close to the positive electrode sheet and the negative electrode sheet, and the coating is provided on the side of the base film close to the negative electrode sheet. This can achieve a better effect of inhibiting dendrite growth.
  • the coating is only provided on at least one of the two sides of the base film along the thickness direction thereof, and the thickness of the coating provided on the side of the base film close to the negative electrode plate is greater than or equal to the thickness of the coating provided on the side of the base film close to the positive electrode plate. This can achieve a better effect of inhibiting dendrite growth.
  • the coating is provided only on at least one side of the two sides of the base film along the thickness direction thereof, and the thickness of the base film is ⁇ 7 ⁇ m.
  • the coating is only provided in the middle of the base film along the thickness direction, and the thickness of the base film on both sides of the coating along the thickness direction is independently ⁇ 9 ⁇ m, and can be 5 ⁇ m to 9 ⁇ m. This is conducive to improving the puncture resistance of the separator while taking into account the energy density of the battery.
  • the coating is only provided in the middle of the base film along the thickness direction thereof, and the coating includes a lithium supplement material, and the mass percentage of the lithium supplement material is ⁇ 10% based on the mass of the fluorocarbon-containing material. Meeting the given conditions can take into account both the dendrite puncture resistance of the isolation film and the energy density of the battery.
  • the puncture strength of the isolation film is ⁇ 350 gf, and can be optionally ⁇ 450 gf.
  • the electronic conductivity of the coating at 25° C. is 10 -6 mS/cm to 10 -10 mS/cm.
  • the second aspect of the present application provides a method for preparing the isolation membrane of the first aspect of the present application, which comprises: forming a coating on at least one of the two sides of the base membrane along the thickness direction; and/or forming the coating in the middle of the base membrane along the thickness direction, wherein the coating comprises a fluorine-containing carbon material, and a solid electrolyte and/or a metal oxide.
  • the isolation membrane prepared by the method is conducive to inhibiting the growth of dendrites and improving the isolation membrane's resistance to dendrite penetration.
  • a coating raw material including a fluorine-containing carbon material, a solid electrolyte and/or a metal oxide, and an adhesive is mixed with a solvent to obtain a coating slurry.
  • the coating slurry is coated on at least one of the two sides of the base film distributed along its thickness direction to obtain the coating; or, the base film includes a first base film and a second base film, and the coating slurry is coated on one of the two sides of the first base film distributed along its thickness direction to form the coating, and the second base film is stacked on the side of the coating away from the first base film.
  • the third aspect of the present application provides a battery, which includes: the isolation membrane of the first aspect of the present application, and/or the isolation membrane prepared by the method for preparing the isolation membrane of the second aspect of the present application.
  • the fourth aspect of the present application provides an electrical device, which includes: the battery of the third aspect of the present application.
  • FIG. 1 is a schematic structural diagram of an isolation membrane according to an embodiment of the present application.
  • FIG. 2 is a schematic structural diagram of an isolation membrane according to yet another embodiment of the present application.
  • FIG3 is a schematic structural diagram of an isolation membrane according to another embodiment of the present application.
  • FIG. 4 is a schematic structural diagram of a battery according to an embodiment of the present application.
  • FIG. 5 is a schematic structural diagram of a battery module according to an embodiment of the present application.
  • FIG. 6 is a schematic structural diagram of a battery pack according to an embodiment of the present application.
  • FIG. 7 is an exploded view of a battery pack according to an embodiment of the present application.
  • FIG. 8 is a schematic diagram of an electric device using a battery as a power source according to an embodiment of the present application.
  • 11 base film
  • 11a side of the base film close to the negative electrode
  • 11b side of the base film close to the positive electrode
  • 111 first sub-base film
  • 112 second sub-base film
  • 12 coating
  • 1 battery
  • 2 battery module
  • 3 battery pack
  • 4 upper case
  • 5 lower case.
  • range disclosed in the present application is defined in the form of a lower limit and/or an upper limit, and a given range is defined by selecting a lower limit and/or an upper limit, and the selected lower limit and/or upper limit define the boundaries of the particular range.
  • the range defined in this way may be inclusive of the end values or exclusive of the end values, and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form an unambiguous range, and any lower limit may be combined with other lower limits to form an unambiguous range, and similarly any upper limit may be combined with any other upper limit to form an unambiguous range.
  • each individually disclosed point or single numerical value itself can be combined as a lower limit or upper limit with any other point or single numerical value or with other lower limits or upper limits to form an unambiguous range.
  • ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also expected.
  • the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4 and 5 are listed, the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.
  • the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers.
  • the numerical range "0-5" means that all real numbers between "0-5" have been listed in this document, and "0-5" is just an abbreviation of these numerical combinations.
  • a parameter when a parameter is expressed as an integer ⁇ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
  • lithium batteries especially lithium metal batteries
  • the isolation membranes that are widely used in related fields usually only serve as physical barriers. As the cycle progresses and the dendrites grow, there is still the possibility of dendrites growing along the pores and piercing.
  • a coating is formed by compounding a fluorine-containing carbon material with one or both of a solid electrolyte and a metal oxide, and the coating is formed on at least one side of the two sides of the diaphragm along its thickness direction and/or the middle of the diaphragm.
  • the isolation membrane disclosed in the embodiment of the present application is suitable for secondary batteries, and the battery disclosed in the embodiment of the present application can be used in electrical equipment that uses the battery as a power source or various energy storage systems that use the battery as an energy storage element.
  • Electrical equipment may include but is not limited to mobile phones, tablets, laptops, electric toys, electric tools, battery cars, electric cars, ships, spacecraft, etc.
  • electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplanes.
  • spacecraft can include airplanes, rockets, space shuttles and spacecraft, etc.
  • the first aspect of the present application provides an isolation membrane, which includes: a base membrane and a coating, the coating including a fluorine-containing carbon material, and a solid electrolyte and/or a metal oxide, the coating being arranged on at least one of the two sides of the base membrane along its thickness direction, and/or the coating being arranged in the middle of the base membrane along its thickness direction.
  • the fluorine-containing carbon material refers to a carbon-based material having a carbon-fluorine covalent bond
  • the solid electrolyte refers to a solid ion conductor electrolyte.
  • the isolation membrane includes a base film 11 and a coating 12, the coating 12 includes a fluorine-containing carbon material, and a solid electrolyte and/or a metal oxide, and the coating 12 is arranged on at least one of the two sides of the base film 11 distributed along its thickness direction (with reference to Figure 1 or Figure 2 for understanding), and/or, the coating 12 is arranged in the middle of the base film 11 along its thickness direction (with reference to Figure 3 for understanding).
  • the coating 12 may include a fluorine-containing carbon material and a solid electrolyte, or may include a fluorine-containing carbon material and a metal oxide, or may include a fluorine-containing carbon material, a solid electrolyte and a metal oxide at the same time.
  • the metal oxide may include, but is not limited to, a transition metal oxide and/or an oxide of a metal having a plurality of different valence states.
  • the material composition of the coating can be obtained by combining one or more analyses of conventional methods, and the conventional methods may include but are not limited to ICP elemental analysis, EDS energy spectrum analysis, XRD test, XPS test, infrared test, atomic absorption method, etc.
  • the position of the coating can be obtained by characterizing the microstructure of the cross-section of the isolation membrane with the help of conventional instruments such as scanning electron microscopes.
  • the isolation membrane can be used for batteries of the type such as lithium batteries or sodium batteries, wherein, by compounding a fluorine-containing carbon material with a solid electrolyte (usually used to prepare a solid electrolyte layer of a solid-state battery) and at least one of a metal oxide and forming a coating on the base membrane of the isolation membrane, it is beneficial to inhibit the generation or growth of dendrites, and can also improve the mechanical strength of the isolation membrane and enhance its resistance to dendrite penetration, thereby achieving a better synergistic effect.
  • a fluorine-containing carbon material usually used to prepare a solid electrolyte layer of a solid-state battery
  • a metal oxide usually used to prepare a solid electrolyte layer of a solid-state battery
  • fluorine-containing carbon materials have high lithium insertion capacity and lithium reaction activity, can react with Li to generate C and LiF, and have no intermediate products, which is beneficial to consume lithium to inhibit the generation of lithium dendrites, and can also react the generated lithium dendrites to inhibit the growth of lithium dendrites (further, forming the coating on the side of the isolation membrane facing the negative electrode is also beneficial to the reaction to generate a LiF interface layer, which helps to form a good and stable SEI and improve the coulomb efficiency, which is more obvious at high rates); in addition, solid electrolytes and metal oxides can also react with lithium or have a certain lithium insertion capacity, and can also consume part of the lithium, thereby inhibiting the generation and growth of lithium dendrites; further, the solid electrolyte also has good ion conductivity, which can improve the ion transmission capacity of the coating and further inhibit the generation of lithium dendrites; further, the base film of the isolation membrane is usually a polymer.
  • the mechanical strength and heat resistance of the solid electrolyte and the metal oxide are relatively better, and the oxygen that may exist in the solid electrolyte and the metal oxide can also combine with the fluorine-containing carbon material to form a denser coating structure. Furthermore, a better synergistic effect can be exerted to reduce the risk of dendrites piercing the isolation membrane and short circuiting within the battery.
  • the isolation membrane of the present application has the following beneficial effects: it can inhibit the growth of dendrites and improve the isolation membrane's resistance to dendrite penetration, thereby reducing the risk of dendrites piercing the isolation membrane and short circuiting within the battery.
  • isolation membrane of the first aspect of the present application may optionally satisfy one or more of the following conditions on the basis of satisfying the above conditions.
  • the general formula of the fluorine-containing carbon material may be CFx, 0.85 ⁇ x ⁇ 1.5.
  • the value of x can be 0.85, 0.9, 1, 1.1, 1.2, 1.25, 1.3, 1.4, 1.5, and the like.
  • the value of x in CFx can be obtained by combining the correlation analysis of the fluorine-carbon bond absorption peak area and the carbon-carbon bond absorption peak area in the infrared spectrum.
  • Increasing the fluorine content (atomic percentage) in the fluorine-containing carbon material is conducive to obtaining improved thermal stability.
  • the fluorine content in the fluorine-containing carbon material meets the given conditions, which is conducive to making the coating have good thermal stability, insulation and ion conductivity, thereby helping to further improve the performance of the battery.
  • the fluorinated carbon material may include one or more of fluorinated graphite, fluorinated carbon black, fluorinated carbon, fluorinated graphene, fluorinated carbon nanotubes, and fluorinated carbon fibers.
  • fluorinated carbon may also include but is not limited to fluorinated (nano) carbon fibers, etc.
  • fluorinated graphite may include but is not limited to fluorinated graphite microsheets, etc.
  • the fluorinated carbon material in the given range has a high lithium insertion capacity and lithium reaction activity, and can be used in lithium batteries or sodium batteries and other types of batteries to inhibit dendrite growth and reduce the risk of dendrites piercing the isolation membrane.
  • the particle size of the fluorine-carbon material may be 50 nm to 5 ⁇ m.
  • the particle size of the fluorine-carbon material may be 50 nm to 1 ⁇ m.
  • the particle size of the fluorocarbon-containing material can be 50nm, 100nm, 200nm, 500nm, 800nm, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, and the like.
  • the particle size of the fluorocarbon-containing material can be measured by combining conventional instruments and methods such as a scanning electron microscope and a particle size analyzer.
  • the increase in the particle size of the fluorocarbon-containing material is conducive to reducing the risk of particles blocking the micropores of the base membrane when forming the coating, thereby reducing the risk of ion transmission channel blocking caused by the decrease in the air permeability of the isolation membrane and the resulting decrease in battery capacity and cycle life; in addition, the increase in the particle size of the fluorocarbon-containing material will also increase the viscosity of the coating slurry.
  • fluorocarbon-containing materials with smaller particle sizes is not only conducive to making the coating slurry obtain a suitable viscosity, reducing the risk of decreased coating uniformity and increased coating difficulty due to the high viscosity of the coating slurry, but also conducive to improving the adhesion effect of the fluorocarbon-containing material on the surface of the base membrane and reducing the risk of powder loss that may occur during the coating process.
  • the particle size of the fluorocarbon-containing material that meets the given range is not only conducive to coating, improving the uniformity and adhesion of the coating, but also conducive to the isolation membrane taking into account the good ion transmission ability.
  • the particle size of the fluorocarbon-containing material can be 50nm to 1 ⁇ m, which is conducive to further taking into account the uniformity of the coating and the ion transmission ability of the isolation membrane.
  • the air permeability of the isolation membrane can be ⁇ 300s/100mL, wherein when the air permeability of the isolation membrane is ⁇ 300s/100mL, the isolation membrane has good air permeability and good ion transmission characteristics.
  • the volume particle size Dv50 of the fluorocarbon-containing material may be 50nm to 1000nm.
  • the volume particle size Dv50 of the fluorocarbon-containing material may be 50nm to 500nm.
  • the volume particle size Dv50 of the fluorocarbon material may be 50nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, and the like.
  • the volume particle size Dv90 of the fluorocarbon-containing material may be ⁇ 3 ⁇ m.
  • the volume particle size Dv90 of the fluorocarbon-containing material may be ⁇ 1 ⁇ m.
  • the volume particle size Dv90 of the fluorocarbon-containing material may be 100 nm to 3 ⁇ m, 200 nm to 1 ⁇ m, 500 nm to 1 ⁇ m, 300 nm, 600 nm, 800 nm, 900 nm, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, and the like.
  • the particle sizes of the solid electrolyte and the metal oxide may be 50 nm to 5 ⁇ m, respectively.
  • the particle sizes of the solid electrolyte and the metal oxide may be 50 nm to 1 ⁇ m, respectively, such as 50 nm, 100nm, 200nm, 500nm, 800nm, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, etc. This is conducive to further taking into account the uniformity of the coating and the ion transmission ability of the isolation membrane.
  • the surface density of the coating may be 3.5 g/m 2 to 15 g/m 2 .
  • the surface density of the coating may be 3.5 g/m 2 , 4 g/m 2 , 5 g/m 2 , 6 g/m 2 , 7 g/m 2 , 8 g/m 2 , 9 g/m 2 , 10 g/m 2 , 11 g/m 2 , 12 g/m 2 , 13 g/m 2 , 14 g/m 2 , 15 g/m 2 , and the like.
  • the surface density of the coating may be measured by conventional methods, for example, the surface density of the coating may be calculated by measuring the weight difference of the isolation film before and after the coating is stripped and the area of the isolation film sample, wherein the stripping method of the coating is not particularly limited, and may include but is not limited to a mechanical stripping method, a solvent immersion method, and the like.
  • the coating thickness or the coating density is beneficial to improving the dendrite puncture resistance of the isolation film, and reducing the coating thickness or the coating density is beneficial to obtaining better ion transmission characteristics.
  • the surface density of the coating satisfies the given range conditions, which is beneficial to reducing the risk of dendrites piercing the isolation membrane and also helps the isolation membrane to have better ion transmission capacity.
  • the surface density of the fluorocarbon material in the coating can be 2g/ m2 to 14.5g/ m2 .
  • the surface density of the fluorocarbon material in the coating can be 2g/ m2 , 3g/ m2 , 4g/ m2 , 5g/ m2 , 6g/m2, 7g/ m2 , 8g/ m2 , 9g/ m2 , 10g/ m2 , 11g/ m2 , 12g/ m2 , 13g/ m2 , 14g/ m2 , 14.5g/ m2 , etc.
  • the surface density of the fluorocarbon material in the coating can be measured by conventional methods, for example, the content relationship between the solid electrolyte and/or metal oxide and the fluorocarbon material in the coating can be obtained by combining one or more conventional methods such as elemental analysis and infrared testing, and calculated in combination with the surface density of the coating.
  • Increasing the content of fluorocarbon materials in the coating is conducive to consuming more lithium through reaction with lithium, improving the inhibition effect on dendrite growth, and increasing the content of solid electrolyte and/or metal oxide in the coating is conducive to improving the strength of the separator itself and improving the ability to resist dendrite piercing.
  • the surface density of the fluorocarbon material in the coating meets the given conditions, which is conducive to further inhibiting dendrite growth and reducing the risk of dendrite piercing the separator.
  • the total mass percentage of the solid electrolyte and/or the metal oxide may be ⁇ 70%.
  • the total mass percentage of the solid electrolyte and/or the metal oxide may be 20% to 50%.
  • the total mass percentage of the solid electrolyte and/or metal oxide can be 70%, 60%, 50%, 40%, 30%, 20%, 10%, and so on.
  • the content relationship of the solid electrolyte and/or metal oxide and the fluorocarbon-containing material can be obtained by combining one or more analyses of conventional methods such as elemental analysis and infrared testing. Increasing the content of the solid electrolyte and/or metal oxide is conducive to further improving the mechanical strength of the isolation membrane and improving the ability of the isolation membrane to resist dendrite puncture.
  • the amount of the solid electrolyte and/or metal oxide meet the given range is not only conducive to improving the dense structure of the coating and improving the ability of the isolation membrane to resist dendrite puncture, but also enables the coating to have a better inhibitory effect on dendrite growth, and is also conducive to making the isolation membrane take into account better ion transmission ability.
  • the total mass percentage of the solid electrolyte and/or metal oxide can be 20% to 50%, which is conducive to further reducing the risk of the isolation membrane being pierced by dendrites and taking into account better ion transmission ability.
  • the wetting angles of the solid electrolyte and the metal oxide may be independently ⁇ 15°.
  • the wetting angles of the solid electrolyte and the metal oxide can be 15°, 12°, 10°, 8°, 5°, etc., respectively, or can be a range of any of the above values.
  • the wetting angles of the solid electrolyte and the metal oxide can be measured using conventional equipment and conventional methods, for example, using a contact angle meter (such as Dataphysics OCA25 video optical contact angle measurement Instruments, etc.), drop the liquid water seat on the solid electrolyte or metal oxide sample, and obtain its contact angle value by fitting the image contour through software.
  • Fluorocarbon materials are highly hydrophobic and have poor affinity with highly polar electrolytes, which is not conducive to the isolation membrane absorbing and retaining electrolytes.
  • Metal oxides usually have good hydrophilicity, and the oxygen-containing functional groups on their surfaces can form hydrogen bonds to improve hydrophilicity. Influenced by factors such as polar hydrophilic groups, solid electrolytes usually also show strong hydrophilicity. Introducing solid electrolytes and/or metal oxides into the coating is also conducive to the isolation membrane absorbing and retaining electrolytes, and making the isolation membrane and the electrode interface fully infiltrated with electrolytes can also improve the problem of the isolation membrane being easily pierced by dendrites to a certain extent. Furthermore, by making the wetting angles of the solid electrolyte and the metal oxide meet the given conditions, the affinity of the isolation membrane with highly polar electrolytes and the problem of the isolation membrane being easily pierced by dendrites can be further improved.
  • the ionic conductivity of the solid electrolyte at 25° C. may be ⁇ 10 ⁇ 4 S/cm.
  • the ionic conductivity of the solid electrolyte at 25°C may be ⁇ 10 -4 S/cm, ⁇ 5 ⁇ 10 -4 S/cm, ⁇ 10 -3 S/cm, ⁇ 5 ⁇ 10 -3 S/cm, ⁇ 10 -2 S/cm, and the like.
  • the ionic conductivity may be obtained by AC impedance testing.
  • the increase in the ionic conductivity of the solid electrolyte is beneficial to improving the ion transport capacity of the isolation membrane.
  • satisfying the given conditions can further improve the ion transport capacity of the isolation membrane and inhibit the growth of lithium dendrites.
  • the solid electrolyte may include one or more of an oxide electrolyte, a sulfide electrolyte, and an acid salt electrolyte.
  • the acid salt electrolyte refers to a solid electrolyte composed of an acid salt material (such as common acid salts such as phosphates and borates), which may include but is not limited to phosphate solid electrolyte materials.
  • the solid electrolyte may include but is not limited to one or more of lithium lanthanum zirconium oxide (LLZO), lithium aluminum titanium phosphate (LATP), lithium titanium phosphate (LTP), lithium aluminum germanium phosphate (LAGP), lithium germanium phosphosulfur sulfide (LGPS), lithium tetrathiophosphate (Li 3 PS 4 ), lithium phosphorus sulfur chlorosulfide (Li 6 PS 5 Cl), etc.
  • LLZO lithium lanthanum zirconium oxide
  • LATP lithium aluminum titanium phosphate
  • LTP lithium titanium phosphate
  • LAGP lithium aluminum germanium phosphate
  • LGPS lithium germanium phosphosulfur sulfide
  • Li 3 PS 4 lithium phosphorus sulfur chloro
  • the solid electrolyte in the given range can be combined with a fluorine-containing carbon material to form a dense structure, or can react with lithium to consume lithium, which is beneficial to improve the puncture resistance of the isolation membrane and inhibit the growth of lithium dendrites.
  • the solid electrolyte may include but is not limited to one or more of Li 7 La 3 Zr 2 O 12 , Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 , Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 , Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 , LiTi 2 (PO 4 ) 3 , Li 3 PS 4 , Li 10 GeP 2 S 12 , and Li 6 PS 5 Cl, which is beneficial to further improve the puncture resistance of the isolation membrane and inhibit the growth of lithium dendrites.
  • the lithium insertion capacity of the metal oxide may be ⁇ 600 mAh/g.
  • the lithium insertion capacity of the metal oxide can be ⁇ 600mAh/g, ⁇ 650mAh/g, ⁇ 700mAh/g, ⁇ 750mAh/g, ⁇ 800mAh/g, ⁇ 850mAh/g, ⁇ 900mAh/g, and the like.
  • the lithium insertion capacity of the metal oxide can be expressed by the reversible capacity when it is used as a negative electrode active material. It can be used as an active material for the negative electrode pole piece and assembled into a battery for charge and discharge tests.
  • a higher lithium insertion capacity can consume more lithium, which is beneficial to further improve the inhibitory effect of the coating on dendrite growth. Therefore, meeting the given conditions can not only improve the mechanical strength of the isolation membrane and improve its puncture resistance, but also help to further inhibit the growth of lithium dendrites.
  • the metal oxide may include one or more of Fe oxide, Sn oxide, Ti oxide, Cu oxide, Mn oxide, Al oxide, Ge oxide, Zr oxide, and Zn oxide.
  • the metal oxide in the given range has a certain lithium insertion capacity or can react with lithium to consume lithium, which can better inhibit the growth of lithium dendrites.
  • the coating 12 may also include: lithium supplement material.
  • lithium supplement material For lithium batteries, the coating consumes a small amount of lithium due to lithium insertion or reaction with lithium. Further addition of lithium supplement material can also help to compensate for the slight capacity loss caused by the consumption of lithium by the coating.
  • the mass percentage of the lithium supplementing material may be ⁇ 25%.
  • the mass percentage of the lithium supplement material can be 25%, 23%, 20%, 15%, 10%, 5%, and so on.
  • the relative amount of the lithium supplement material and the fluorinated carbon material can be determined by combining conventional methods such as elemental analysis, XRD testing, infrared testing, etc.
  • the specific type and content of the fluorinated carbon material and the lithium supplement material in the coating can be determined and obtained by calculation.
  • controlling the content of the lithium supplement material within the given range is not only conducive to compensating for the slight capacity loss of the battery that may be caused by the consumption of lithium by the coating, but also reduces the risk of excessive self-consumption of lithium in the coating due to the large amount of lithium supplement material, resulting in a decrease in the storage capacity and reaction capacity of lithium outside the coating, thereby weakening the coating's inhibitory effect on lithium dendrite growth.
  • the lithium supplement material may include one or more of LiF, Li 3 N, M-coated Li 2 O, and Li x Si-coated Li 2 O, M includes one or more of Fe, Co, Ni, and Mn, and the value range of x is 0.5-3.75.
  • the value of x can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 3.75, etc.
  • the specific type of lithium supplement material can be determined by combining one or more conventional methods such as elemental analysis, atomic absorption spectrometry, XRD testing, etc.
  • the given lithium supplement material is conducive to achieving a better lithium supplement effect at a lower dosage.
  • the use of M or Li x Si coated Li 2 O can form a passivation layer on the surface of Li 2 O to play a role in slow release of lithium supplement, and can also avoid the capacity attenuation caused by Li 2 O contacting with air before addition.
  • the coating further includes: one or more of a binder, a dispersant, and a thickener.
  • a binder can improve the adhesion strength between the coating and the base film and reduce the risk of powdering of each component in the coating;
  • adding a dispersant is beneficial to improving the dispersion uniformity of the coating slurry, thereby improving the uniformity of the coating;
  • adding a thickener is beneficial to improving the stability of the coating slurry, reducing the risk of stratification or sedimentation, and improving the coating effect and uniformity of the coating.
  • the binder, the dispersant, and the thickener can be independently selected from conventional options in the relevant field, and can be prepared by conventional methods or obtained commercially.
  • the binder can include but is not limited to one or more of polyvinylidene fluoride (PVDF), styrene butadiene rubber (SBR), etc.;
  • the dispersant can include but is not limited to one or more of hydrolyzed polymaleic anhydride, acrylic acid block polymer, polyester block polymer, polyethylene glycol type polyol and polyethyleneimine derivatives;
  • the thickener can include but is not limited to one or more of sodium hydroxymethylcellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, polyacrylate, polyurethane, polyether, etc.
  • the mass percentage of the binder can be 0.5% to 5% based on the mass of the coating.
  • the mass percentage of the binder can be 1% to 3%.
  • it can be 0.5%, 1%, 2%, 3%, 4%, 5%, etc.
  • the mass percentage of the dispersant may be ⁇ 2% based on the mass of the fluorocarbon-containing material.
  • the mass percentage of the dispersant may be 1% to 1.5%.
  • it may be 0.1%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 2%, etc.
  • the uniformity of the coating may be effectively improved.
  • the mass percentage of the thickener may be ⁇ 2%.
  • the mass percentage of the thickener may be 1% to 1.5%, for example, 0.5%, 1%, 2%, 3%, 4%, 5%, etc.
  • the operability of coating and the uniformity of the coating may be effectively improved.
  • the thickness of the single-layer coating may be 1.5 ⁇ m to 3.5 ⁇ m.
  • the thickness of the single-layer coating may be 1.5 ⁇ m to 3 ⁇ m.
  • the thickness of a single-layer coating can be 1.5 ⁇ m, 2 ⁇ m, 2.5 ⁇ m, 3 ⁇ m, 3.5 ⁇ m, and so on.
  • the thickness of the coating can be measured by a film thickness meter. Meeting the given conditions can not only improve the strength of the isolation film and inhibit the growth of dendrites, but also improve the ability of the isolation film to resist dendrite penetration, and obtain better processability, while also reducing the risk of increased reversible capacity loss of the battery and decreased battery energy density caused by excessive coating thickness.
  • the ratio of the total thickness of the coating layer to the thickness of the base film may be 1:(2.5-10).
  • the ratio of the total thickness of the coating to the thickness of the base film can be 1/2.5, 1/3, 1/4, 1/5, 1/6, 1/7, 1/8, 1/9, 1/10, etc.
  • the thickness of the base film can also be measured using a film thickness meter. Meeting the given conditions is conducive to further reducing the risk of increased battery reversible capacity loss and decreased battery energy density caused by excessive coating thickness on the basis of obtaining better dendrite puncture resistance for the isolation film.
  • the coating 12 may be provided only on at least one of the two sides of the base film 11 along the thickness direction thereof, the two sides of the base film 11 along the thickness direction thereof are respectively close to the positive electrode sheet and the negative electrode sheet, and the side 11a of the base film 11 close to the negative electrode sheet may be provided with the coating 12. This can be understood with reference to FIG1. Providing a coating on the side of the base film facing the negative electrode sheet can further improve the effect of inhibiting dendrite growth.
  • the coating 12 may be provided only on at least one of the two sides of the base film 11 distributed along its thickness direction, and the thickness of the coating 12 provided on the side 11a of the base film 11 close to the negative electrode sheet may be ⁇ the thickness of the coating 12 provided on the side 11b of the base film 11 close to the positive electrode sheet.
  • the coating 12 may be provided only on at least one of the two sides of the base film 11 distributed along its thickness direction, and the thickness of the coating 12 provided on the side 11a of the base film 11 close to the negative electrode sheet may be ⁇ the thickness of the coating 12 provided on the side 11b of the base film 11 close to the positive electrode sheet.
  • Figure 2 for understanding. Providing coatings on both sides of the base film along its thickness direction is conducive to further improving the mechanical strength and puncture resistance of the separator, and even if one side of the separator is punctured by dendrites, it is conducive to delaying the time of being completely punctured.
  • the thickness of the coating 12 provided on the side 11a of the base film 11 close to the negative electrode sheet may be greater than the thickness of the coating 12 provided on the side 11b of the base film 11 close to the positive electrode sheet, thereby further improving the inhibitory effect on dendrite growth.
  • the coating 12 may be provided only on at least one of the two sides of the base film 11 along the thickness direction thereof, and the thickness of the base film may be ⁇ 7 ⁇ m.
  • the thickness of the base film may be 7 ⁇ m, 8 ⁇ m, 10 ⁇ m, 12 ⁇ m, 15 ⁇ m, etc. Meeting the given conditions is conducive to further reducing the risk of being pierced by dendrites.
  • the coating 12 may be provided only in the middle of the base film 11 along the thickness direction thereof.
  • the thickness of the base film on both sides of the coating 12 along the thickness direction may be independently ⁇ 9 ⁇ m.
  • the thickness of the base film on both sides of the coating 12 along the thickness direction may be independently 5 ⁇ m to 9 ⁇ m.
  • the base film 11 may include a first sub-base film 111 and a second sub-base film 112 arranged along its thickness direction, and the coating 12 may be sandwiched between the first sub-base film 111 and the second sub-base film 112.
  • This arrangement can avoid direct contact between the coating and the pole piece, which is beneficial to reduce the attenuation of the battery capacity that may be caused by the reaction of the solid electrolyte and/or metal oxide with lithium on the basis of improving the puncture resistance of the isolation film.
  • the thickness of the first sub-base film 111 and the second sub-base film 112 can be independently ⁇ 9 ⁇ m, and can be independently 5 ⁇ m to 9 ⁇ m.
  • the thickness of the first sub-base film 111 and the second sub-base film 112 can be independently 9 ⁇ m, 8 ⁇ m, 7 ⁇ m, 6 ⁇ m, 5 ⁇ m, 4 ⁇ m, etc., and meeting the given conditions is beneficial to further take into account the energy density of the battery on the basis of reducing the risk of the isolation film being pierced by dendrites.
  • the coating 12 may be provided only in the middle of the base film 11 along its thickness direction, and the coating 12 may include a lithium supplement material. Based on the mass of the fluorocarbon material, the mass percentage of the lithium supplement material may be ⁇ 10%. Exemplarily, the mass percentage of the lithium supplement material may be 10%, 8%, 5%, 3%, and so on. With reference to FIG3 , when the coating 12 may be sandwiched between the first sub-base film 111 and the second sub-base film 112, the amount of lithium consumed by the reaction of the solid electrolyte and/or metal oxide with lithium is also small.
  • Controlling the content of the lithium supplement material within the given range is not only conducive to compensating for the slight capacity loss of the battery that may be caused by the consumption of lithium by the coating, but also reduces the risk of weakening the inhibitory effect of the coating on the growth of lithium dendrites due to the large amount of lithium supplement material.
  • the puncture strength of the isolation membrane may be ⁇ 350 gf.
  • the puncture strength of the isolation membrane may be ⁇ 350 gf, ⁇ 400 gf, ⁇ 450 gf, ⁇ 500 gf, ⁇ 550 gf, ⁇ 650 gf, ⁇ 700 gf, ⁇ 750 gf, ⁇ 800 gf, and the like. Meeting the given conditions may further reduce the risk of the isolation membrane being punctured by dendrites.
  • the puncture strength of the isolation membrane may be ⁇ 450 gf.
  • the electronic conductivity of the coating at 25° C. may be 10 -6 mS/cm to 10 -10 mS/cm. This can not only further reduce the negative impact of the coating on the impedance of the isolation membrane, but also inhibit the transfer of electrons through the isolation membrane, thereby reducing the risk of short circuits in the battery.
  • the second aspect of the present application provides a method for preparing the isolation membrane of the first aspect of the present application, which comprises: forming a coating on at least one of the two sides of the base membrane along the thickness direction; and/or forming a coating on the middle part of the base membrane along the thickness direction, the coating comprising a fluorine-containing carbon material, and a solid electrolyte and/or a metal oxide.
  • the isolation membrane prepared by the method is conducive to inhibiting dendrite growth and improving the isolation membrane's resistance to dendrite penetration.
  • a coating raw material including a fluorocarbon material, a solid electrolyte and/or a metal oxide, and an adhesive can be mixed with a solvent to obtain a coating slurry.
  • a fluorocarbon material such as graphite fluoride powder can be uniformly dispersed in a solvent according to a preset ratio for primary dispersion, and then a binder is added for secondary dispersion.
  • a dispersant can also be added to the primary dispersion, and the dispersion method is not limited to ultrasonic dispersion, wherein the ultrasonic time can be flexibly selected according to actual conditions.
  • a thickener can also be added to the secondary dispersion.
  • the primary dispersion and the secondary dispersion can be performed separately and independently under stirring conditions.
  • the stirring speed during the primary dispersion can be 700 rpm to 1200 rpm, and the mixing time can be 30 min to 60 min; the stirring speed during the secondary dispersion can be 1000 rpm to 1600 rpm, and the mixing time can be 30min ⁇ 90min.
  • the specific type of the solvent is not particularly limited, and those skilled in the art can flexibly select it according to actual needs, for example, it can include but is not limited to one or more of deionized water, NN dimethylformamide (DMF), NN methylpyrrolidone (NMP), NN dimethylacetamide (DMAC), tetrahydrofuran (THF), etc.
  • the mass percentage of the solvent can be 55% ⁇ 75%, and can be 60% ⁇ 70% optionally. Meeting the given conditions is conducive to making the coating slurry have better viscosity and stability, and then it is conducive to obtaining better coating effect and coating uniformity. It should be noted that the selection and relative dosage of fluorocarbon materials, solid electrolytes, metal oxides, binders, dispersants and thickeners have been described in detail in the previous section and will not be repeated here.
  • a coating slurry can be prepared and uniformly coated on a base film, and after drying, a barrier film with a coating can be obtained.
  • the coating includes but is not limited to scraping; the drying conditions are not particularly limited, and those skilled in the art can flexibly select according to actual needs, for example, the drying temperature can be 60°C to 80°C, and the drying time can be 5min to 30min.
  • the drying temperature can be 60°C to 80°C
  • the drying time can be 5min to 30min.
  • a coating slurry may be applied to at least one of the two sides of the base film distributed along the thickness direction thereof to obtain a coating; or, the base film includes a first base film and a second base film, and a coating slurry may be applied to one of the two sides of the first base film distributed along the thickness direction thereof to form a coating, and the second base film may be stacked on the side of the coating away from the first base film.
  • the coating on the first base film may be dried under vacuum conditions and then the second base film may be stacked on the side of the coating away from the first base film for compounding.
  • the third aspect of the present application provides a battery, which includes: the isolation membrane of the first aspect of the present application, and/or the isolation membrane prepared by the method for preparing the isolation membrane of the second aspect of the present application.
  • the battery may be a secondary battery, that is, a battery that can be continuously used by activating the active material by charging after discharge.
  • a battery typically includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte.
  • active ions are embedded and released back and forth between the positive electrode sheet and the negative electrode sheet.
  • the separator is arranged between the positive electrode sheet and the negative electrode sheet to serve as an isolation.
  • the electrolyte serves to conduct ions between the positive electrode sheet and the negative electrode sheet.
  • the raw material composition and structure of the positive electrode sheet, the raw material composition and structure of the negative electrode sheet, the material and structural characteristics of the separator, the composition of the electrolyte, etc. can all be conventional choices in the art.
  • the embodiments of the present application do not have any special restrictions on the type of battery, which may include but is not limited to lithium batteries, sodium batteries, etc. In this application, lithium batteries are used as an example for detailed description:
  • the positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, and the positive electrode active material layer may include a positive electrode active material.
  • the positive electrode current collector may be a conventional metal foil or a composite current collector (a metal material may be disposed on a polymer substrate to form a composite current collector).
  • the positive electrode current collector may include at least one of copper foil, aluminum foil, nickel foil, stainless steel foil, stainless steel mesh, and carbon-coated aluminum foil, and may be aluminum foil.
  • the positive electrode active material can be a positive electrode active material commonly used in lithium-ion batteries, and can be a reversibly embedded and deintercalated Li + Compounds, for example, may include but are not limited to lithium-containing composite oxides represented by Li x M′O 2 or Li y M′ 2 O 4 (M is a transition metal element, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 2), spinel-like oxides, layered metal chalcogenides, olivine-structured positive electrode active materials, etc.
  • Exemplarily may include but are not limited to lithium cobalt oxides such as LiCoO 2 , lithium manganese oxides such as LiMn 2 O 4 , lithium nickel oxides such as LiNiO 2 , lithium titanium oxides such as Li 4/3 Ti 5/3 O 4 , lithium manganese nickel composite oxides, lithium manganese nickel cobalt composite oxides, materials with olivine-type crystal structures such as LiM′′PO 4 (M′′ includes one or more of Fe, Mn, Ni), etc.
  • lithium cobalt oxides such as LiCoO 2
  • lithium manganese oxides such as LiMn 2 O 4
  • lithium nickel oxides such as LiNiO 2
  • lithium titanium oxides such as Li 4/3 Ti 5/3 O 4
  • lithium manganese nickel composite oxides lithium manganese nickel cobalt composite oxides
  • materials with olivine-type crystal structures such as LiM′′PO 4 (M′′ includes one or more of Fe, Mn, Ni), etc.
  • a lithium-containing composite oxide with a layered structure or a spinel structure may be used, such as lithium manganese nickel composite oxides represented by LiCoO2 , LiMn2O4 , LiNiO2 , LiNi1 /2Mn1 /2O2 , etc. , lithium manganese nickel cobalt composite oxides represented by LiNi1 / 3Mn1 / 3Co1 / 3O2 , LiNi0.6Mn0.2Co0.2O2 , etc. , or lithium-containing composite oxides such as LiNi1-xyzCoxAlyMgzO2 ( 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.1 , 0 ⁇ z ⁇ 0.1 , 0 ⁇ 1 -xyz ⁇ 1).
  • the above-mentioned lithium-containing composite oxides may also include but are not limited to lithium-containing composite oxides doped with elements such as Ge, Ti, Zr, Mg, Al, Mo, and Sn. It can also be understood that the positive electrode active material can be used alone or in combination. For example, by using a layered lithium-containing composite oxide and a spinel lithium-containing composite oxide at the same time, both large capacity and improved stability can be achieved.
  • conductive additives such as carbon black and acetylene black, or binders such as polyvinylidene fluoride and polyethylene oxide may be appropriately added to the positive electrode active material layer, and other optional additives may be optionally included. After the positive electrode slurry is prepared, it is coated on the positive electrode collector.
  • the negative electrode sheet generally includes a negative electrode current collector and a negative electrode active material layer disposed on the negative electrode current collector, wherein the negative electrode active material layer includes a negative electrode active material.
  • the negative electrode current collector may be a conventional metal foil or a composite current collector (for example, a metal material may be disposed on a polymer substrate to form a composite current collector).
  • the negative electrode current collector may be a copper foil.
  • the negative electrode active material may be a negative electrode active material commonly used in lithium ion batteries, and may be a compound capable of intercalating and deintercalating lithium metal or lithium.
  • it may include, but is not limited to, alloys or oxides of aluminum, silicon, tin, etc., carbon materials, and the like.
  • Oxides may include, but are not limited to, titanium dioxide, etc.
  • carbon materials may include, but are not limited to, graphite, pyrolytic carbon, coke, glassy carbon, sintered bodies of organic polymer compounds, mesophase carbon microbeads, and the like.
  • conductive additives such as carbon black, acetylene black, or binders such as styrene-butadiene rubber, polyvinylidene fluoride, polyethylene oxide, etc. may be appropriately added to the negative electrode active material layer, and other optional additives may be optionally included.
  • conductive additives such as carbon black, acetylene black, or binders such as styrene-butadiene rubber, polyvinylidene fluoride, polyethylene oxide, etc.
  • the battery of the third aspect of the present application may also be a lithium metal battery, in which case its negative electrode active material may include but is not limited to metallic lithium.
  • the negative electrode active material may also be an alloy formed by metallic lithium and other various metals or non-metallic elements.
  • the battery of the third aspect of the present application may also be a negative electrode-free lithium metal battery.
  • the negative electrode may be composed only of a metal foil current collector without lithium metal on its surface. During the cycle, only the lithium in the positive electrode is used, which is precipitated and stripped off in the form of lithium metal on the negative electrode side.
  • the electrolyte solution may include an electrolyte salt and a solvent.
  • the solvent may use a non-aqueous solvent (organic solvent) as a non-aqueous electrolyte.
  • the non-aqueous solvent may include but is not limited to carbonates, ethers, and the like.
  • the carbonate solvent may include, but is not limited to, cyclic carbonate and chain carbonate
  • the cyclic carbonate may include, but is not limited to, ethylene carbonate, propylene carbonate, butylene carbonate, ⁇ -butyrolactone, sulfur esters (ethylene glycol sulfide, etc.), etc.
  • Chain carbonate may include, but is not limited to, low-viscosity polar chain carbonate represented by dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, etc., and aliphatic branched-chain carbonate compounds.
  • the carbonate solvent may be a mixed solvent comprising cyclic carbonate (particularly ethylene carbonate) and chain carbonate.
  • the ether solvent may include, but is not limited to, one or more of tetraethylene glycol dimethyl ether (TEGDME), ethylene glycol dimethyl ether (DME), 1,3-dioxolane (DOL), and the like.
  • TEGDME tetraethylene glycol dimethyl ether
  • DME ethylene glycol dimethyl ether
  • DOL 1,3-dioxolane
  • nonaqueous solvents that can be used include chain alkyl esters such as methyl propionate, chain triesters such as trimethyl phosphate, nitrile solvents such as 3-methoxypropionitrile, and branched compounds having ether bonds such as dendrimers.
  • fluorine-based solvents may also be used.
  • the fluorine-based solvents may include but are not limited to H(CF 2 ) 2 OCH 3 , C 4 F 9 OCH 3 , H(CF 2 ) 2 OCH 2 CH 3 , H(CF 2 ) 2 OCH 2 CF 3 , H(CF 2 ) 2 CH 2 O(CF 2 ) 2 H, etc., or may include but are not limited to CF 3 CHFCF 2 OCH 3 , CF 3 CHFCF 2 OCH 2 CH 3 and the like, i.e., 2-trifluoromethylhexafluoropropyl methyl ether, 2-trifluoromethylhexafluoropropyl ethyl ether, 2-trifluoromethylhexafluoropropyl propyl ether, 3-trifluoromethyloctafluorobutyl methyl ether, 3-trifluoromethyloctafluorobutyl methyl ether, 3-trifluoromethyl
  • the electrolyte salt may include but is not limited to lithium perchlorate, organic boron lithium salt, lithium salt of fluorine-containing compound, lithium imide salt, etc., and may include but is not limited to LiClO 4 , LiPF 6 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 2 F 4 (SO 3 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiC(CF 3 SO 2 ) 3 , LiC n F 2n+1 SO 3 (n ⁇ 2), LiN(RfOSO 2 ) 2 (wherein Rf is a fluoroalkyl group), etc.
  • LiClO 4 LiPF 6 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 2 F 4 (SO 3 ) 2 , LiN(C 2 F 5 SO 2 ) 2 , LiC
  • the electrolyte salt may include a fluorine-containing organic lithium salt, which is easily soluble in a non-aqueous electrolyte due to its large anionicity and easy separation into ions.
  • the concentration of the electrolyte lithium salt in the electrolyte can be ⁇ 0.3 mol/L, optionally ⁇ 0.7 mol/L, optionally ⁇ 1.7 mol/L, and further optionally ⁇ 1.2 mol/L. Controlling the concentration of the electrolyte lithium salt within the given range can not only obtain better ion conductivity, but also help avoid the problem of electrolyte salt precipitation due to failure of the electrolyte salt to dissolve completely.
  • the electrolyte may further include additives.
  • the additives may include negative electrode film-forming additives, positive electrode film-forming additives, or additives that can improve certain battery properties, such as but not limited to additives that improve battery overcharge performance, additives that improve battery high temperature performance, additives that improve battery low temperature performance, etc.
  • the isolation membrane adopts the isolation membrane of the first aspect of the present application or the isolation membrane prepared by the method of the second aspect of the present application.
  • the present application has no special restrictions on the base membrane of the isolation membrane, and any known porous structure membrane with electrochemical stability and mechanical stability can be selected according to actual needs, for example, it can include but is not limited to a single-layer or multi-layer film containing at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • FIG4 is a square-structured battery 1 as an example.
  • the battery may include an outer packaging for packaging the positive electrode sheet, the negative electrode sheet, and the electrolyte.
  • the outer package may include a shell and a cover plate.
  • the shell may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose a receiving cavity.
  • the shell has an opening connected to the receiving cavity, and the cover plate can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the separator can be wound or laminated to form an electrode assembly.
  • the electrode assembly is packaged in the receiving cavity.
  • the number of electrode assemblies contained in the battery can include one or more, which can be adjusted according to demand.
  • the outer packaging of the battery may include a hard shell, such as a hard plastic shell, an aluminum shell, or a steel shell.
  • the outer packaging of the battery may also include a soft package, such as a bag-type soft package.
  • the material of the soft package may be plastic, such as at least one of polypropylene (PP), polybutylene terephthalate (PBT), and polybutylene succinate (PBS).
  • the battery may be either a single battery cell or a battery module or battery pack assembled from battery cells.
  • the battery module or battery pack may contain multiple batteries, and the specific number may be adjusted according to the application and capacity of the battery module.
  • FIG5 is a battery module 2 as an example.
  • a plurality of batteries 1 may be arranged in sequence along the length direction of the battery module 2. Of course, they may also be arranged in any other manner. Further, the plurality of batteries 1 may be fixed by fasteners.
  • the battery module 2 may also include a housing having a storage space, in which a plurality of batteries 1 are stored.
  • the battery modules may be assembled into a battery pack, and the number of battery modules contained in the battery pack may be adjusted according to the application and capacity of the battery pack.
  • FIG6 and FIG7 are battery packs 3 as an example.
  • the battery pack 3 may include a battery box and a plurality of battery modules 2 disposed in the battery box.
  • the battery box includes an upper box body 4 and a lower box body 5, and the upper box body 4 can be covered on the lower box body 5 to form a closed space for accommodating the battery modules 2.
  • the plurality of battery modules 2 can be arranged in the battery box in any manner.
  • the fourth aspect of the present application provides an electrical device, which includes: the battery of the third aspect of the present application.
  • the battery can be used as a power source for the electrical device or as an energy storage unit for the electrical device.
  • the electrical device may include, but is not limited to, mobile devices (e.g., mobile phones, laptops), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks), electric trains, ships, satellites, and energy storage systems.
  • FIG8 is an example of an electric device.
  • the electric device includes a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid Power electric vehicles.
  • electric devices may include mobile phones, tablet computers, and laptop computers. Such electric devices are usually required to be thin and light, and batteries may be used as power sources.
  • the mass ratio of fluorinated graphite powder, hydrolyzed polymaleic anhydride, sodium hydroxymethyl cellulose and PVDF is 1:0.3:0.01:0.01:0.03
  • the mass percentage of solvent NMP in the coating slurry is 65%.
  • Puncture strength test of separator Referring to the requirements of GB/T 36363-2018 Polyolefin separator for lithium-ion batteries, the separator is flattened and clamped in the fixture, and punctured at a rate of (100+10) mm/min. After completion, take out the sample and perform a thickness test at 4 points around the pinhole in accordance with the provisions of GB/T 6672-2001. Take the average value and calculate the puncture strength.
  • Isolation film air permeability test refer to GB/T36363-2018 standard.
  • Example 2 to 19 and Comparative Examples 1 to 3 and Example 1 are detailed in Table 1.
  • Example 2 to 19 and Comparative Examples 1 to 3 the total mass of the fluorine-containing carbon material, the solid electrolyte and the metal oxide in the coating remains unchanged.
  • appropriately increasing the particle size of the fluorocarbon-containing material has a positive promoting effect on improving the air permeability of the isolation membrane
  • appropriately reducing the particle size of the fluorocarbon-containing material has a promoting effect on improving the tensile strength and thermal yield of the isolation membrane.
  • Keeping the particle size of the fluorocarbon-containing material within a reasonable range is beneficial to taking into account the air permeability, mechanical strength and thermal shrinkage of the isolation membrane at the same time.

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Abstract

一种隔离膜及其制备方法、电池和用电装置。所述隔离膜包括：基膜和涂层，所述涂层包括含氟碳材料，以及固态电解质和/或金属氧化物，所述涂层设在所述基膜沿其厚度方向分布的两侧中的至少一侧，和/或，所述涂层设在所述基膜沿其厚度方向的中部。由此，可以抑制枝晶生长，并改善隔离膜的耐枝晶刺穿能力，从而可以降低枝晶刺穿隔离膜和电池内短路的风险。

Description

隔离膜及其制备方法、电池和用电装置 技术领域
本申请属于电池领域，具体而言，涉及隔离膜及其制备方法、电池和用电装置。
背景技术
电池作为储能装置，广泛应用于各个领域。以锂离子电池为例，其具有绿色、环保、高能、低碳等特点，不仅被应用于水力、火力、风力和太阳能电站等储能电源系统，还被广泛应用于电动自行车、电动摩托车、电动汽车、船舶等电动交通工具，以及军事装备和航空航天等多个领域。随着当前社会的发展，人们对于电池的要求也越来越高。
公开内容
鉴于背景技术中存在的技术问题，本申请提供一种隔离膜，旨在抑制枝晶刺穿隔离膜。
为了实现上述目的，本申请的第一方面提供了一种隔离膜，其包括：
基膜和涂层，所述涂层包括含氟碳材料，以及固态电解质和/或金属氧化物，所述涂层设在所述基膜沿其厚度方向分布的两侧中的至少一侧，和/或，所述涂层设在所述基膜沿其厚度方向的中部。
本申请的隔离膜具有以下有益效果：可以抑制枝晶生长，并改善隔离膜的耐枝晶刺穿能力，从而可以降低枝晶刺穿隔离膜和电池内短路的风险。
在本申请的一些实施例中，所述含氟碳材料的通式为CFx，0.85≤x≤1.5，可选地，1≤x≤1.25。由此有利于进一步改善电池的使用性能。
在本申请的一些实施例中，所述含氟碳材料包括氟化石墨、氟化炭黑、氟化碳、氟化石墨烯、氟化碳纳米管、氟化碳纤维中的一种或多种。由此，可以降低隔离膜被枝晶刺穿的风险。
在本申请的一些实施例中，所述含氟碳材料的粒径为50nm～5μm，可选为50nm～1μm。满足所给条件既有利于改善涂层的均匀性和附着效果，还有利于使隔离膜兼顾较好的离子传输能力。
在本申请的一些实施例中，所述含氟碳材料的体积粒径Dv50为50nm～1000nm，可选为50nm～500nm。由此有利于进一步兼顾涂层的均匀性和隔离膜的离子传输能力。
在本申请的一些实施例中，所述含氟碳材料的体积粒径Dv90≤3μm，可选≤1μm。由此有利于进一步兼顾涂层的均匀性和隔离膜的离子传输能力。
在本申请的一些实施例中，所述涂层的面密度为3.5g/m2～15g/m2；和/或，所述涂层中含氟碳材料的面密度为2g/m2～14.5g/m2。
在本申请的一些实施例中，以所述含氟碳材料的质量为基准，所述固态电解质和/或所述金属氧化物的总的质量百分含量≤70％，可选为20％～50％。由此有利于进一步降低隔离膜被枝晶刺穿 的风险，并兼顾较好的离子传输能力。
在本申请的一些实施例中，所述固态电解质和所述金属氧化物的润湿角分别独立地≤15°。由此可以改善隔离膜与强极性的电解液亲合性和隔离膜易被枝晶刺穿的问题。
在本申请的一些实施例中，所述固态电解质在25℃下的离子电导率≥10-4S/cm。满足所给条件可以进一步改善隔离膜的离子传输能力，抑制锂枝晶生长。
在本申请的一些实施例中，所述金属氧化物的嵌锂容量≥600mAh/g。由此有利于进一步改善隔离膜的耐刺穿能力并抑制锂枝晶的生长。
在本申请的一些实施例中，所述固态电解质包括氧化物电解质、硫化物电解质、酸盐电解质中的一种或多种，可选地，包括Li7La3Zr2O12、Li1.4Al0.4Ti1.6(PO4)3、Li1.5Al0.5Ge1.5(PO4)3、Li1.3Al0.3Ti1.7(PO4)3、LiTi2(PO4)3、Li3PS4、Li10GeP2S12、Li6PS5Cl中的一种或多种。由此有利于进一步改善隔离膜的耐刺穿能力并抑制锂枝晶的生长。
在本申请的一些实施例中，所述金属氧化物包括Fe的氧化物、Sn的氧化物、Ti的氧化物、Cu的氧化物、Mn的氧化物、Al的氧化物、Ge的氧化物、Zr的氧化物、Zn的氧化物中的一种或多种。由此可以较好的抑制枝晶的生成。
在本申请的一些实施例中，所述涂层还包括：补锂材料。由此还有利于弥补因涂层对锂的消耗可能引起的微量容量损失。
在本申请的一些实施例中，以所述含氟碳材料的质量为基准，所述补锂材料的质量百分含量≤25％。由此既有利于弥补因涂层对锂的消耗可能引起的电池的微量容量损失，还有利于避免因补锂材料用量过多可能引起的涂层对锂枝晶生长抑制效果削弱的风险。
在本申请的一些实施例中，所述补锂材料包括LiF、Li3N、M包覆的Li2O、LixSi包覆的Li2O中的一种或多种，M包括Fe、Co、Ni、Mn中的一种或多种元素，x的取值范围为0.5～3.75。由此有利于在较低的用量下达到较好的补锂效果。
在本申请的一些实施例中，所述涂层还包括：粘结剂、分散剂、增稠剂中的一种或多种。
在本申请的一些实施例中，以所述涂层的质量为基准，所述涂层满足以下条件中的一个或多个：(I)所述粘结剂的质量百分含量为0.5％～5％；(II)所述分散剂的质量百分含量≤2％；(III)所述增稠剂的质量百分含量≤2％。
在本申请的一些实施例中，以所述涂层的质量为基准，所述涂层满足以下条件中的一个或多个：(i)所述粘结剂的质量百分含量为1％～3％；(ii)所述分散剂的质量百分含量为1％～1.5％；(iii)所述增稠剂的质量百分含量为1％～1.5％。
在本申请的一些实施例中，单层所述涂层的厚度为1.5μm～3.5μm，可选为1.5μm～3μm。由此不仅可以提高隔离膜耐枝晶刺穿的能力，还能降低因涂层厚度过大可能引起的电池可逆容量损失增加以及电池能量密度下降等问题的风险。
在本申请的一些实施例中，所述涂层的总厚度≤5μm。由此有利于进一步降低因涂层厚度过大可能引起的电池可逆容量损失增加以及电池能量密度下降等问题的风险。
在本申请的一些实施例中，所述涂层的总厚度与所述基膜的厚度的比值为1：(2.5～10)。满足所给条件可以兼顾隔离膜的耐枝晶刺穿能力和电池的能量密度。
在本申请的一些实施例中，所述涂层仅设在所述基膜沿其厚度方向分布的两侧中的至少一侧，所述基膜沿其厚度方向分布的两侧分别靠近正极极片和负极极片，所述基膜靠近负极极片的一侧设有所述涂层。由此能起到较好的抑制枝晶生长的效果。
在本申请的一些实施例中，所述涂层仅设在所述基膜沿其厚度方向分布的两侧中的至少一侧，设在所述基膜靠近所述负极极片的一侧的所述涂层的厚度≥设在所述基膜靠近所述正极极片的一侧的所述涂层的厚度。由此能起到较好的抑制枝晶生长的效果。
在本申请的一些实施例中，所述涂层仅设在所述基膜沿其厚度方向分布的两侧中的至少一侧，所述基膜的厚度≥7μm。
在本申请的一些实施例中，所述涂层仅设在所述基膜沿其厚度方向的中部，位于所述涂层沿其厚度方向的两侧的所述基膜的厚度分别独立地≤9μm，可选为5μm～9μm。由此有利于在改善隔离膜耐刺穿能力的基础上兼顾电池的能量密度。
在本申请的一些实施例中，所述涂层仅设在所述基膜沿其厚度方向的中部，所述涂层中包括补锂材料，以所述含氟碳材料的质量为基准，所述补锂材料的质量百分含量≤10％。满足所给条件可以兼顾隔离膜的耐枝晶刺穿能力和电池的能量密度。
在本申请的一些实施例中，所述隔离膜的刺穿强度≥350gf，可选≥450gf。
在本申请的一些实施例中，所述涂层在25℃下的电子电导率为10-6mS/cm～10-10mS/cm。
本申请的第二方面提出了一种制备本申请第一方面的隔离膜的方法，其包括：在基膜沿其厚度方向分布的两侧中的至少一侧形成涂层；和/或，在所述基膜沿其厚度方向的中部形成所述涂层，所述涂层包括含氟碳材料，以及固态电解质和/或金属氧化物。采用该方法制得的隔离膜有利于抑制枝晶生长，并改善隔离膜的耐枝晶刺穿能力。
在本申请的一些实施例中，将包括含氟碳材料、固态电解质和/或金属氧化物、粘接剂在内的涂层原料与溶剂混合，得到涂层浆料。
在本申请的一些实施例中，在所述基膜沿其厚度方向分布的两侧中的至少一侧涂覆所述涂层浆料，得到所述涂层；或者，所述基膜包括第一基膜和第二基膜，在所述第一基膜沿其厚度方向分布的两侧中的其中一侧涂覆所述涂层浆料，形成所述涂层，并将所述第二基膜叠放于所述涂层远离所述第一基膜的一侧上。
本申请的第三方面提出了一种电池，其包括：本申请第一方面的隔离膜，和/或采用本申请第二方面的制备隔离膜的方法制得的隔离膜。
本申请的第四方面提供了一种用电装置，其包括：本申请第三方面的电池。
本申请的附加方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本申请的实践了解到。
附图说明
本申请的上述和/或附加的方面和优点从结合下面附图对实施例的描述中将变得明显和容易理解，其中：
图1是根据本申请一实施方式的隔离膜的结构示意图。
图2是根据本申请再一实施方式的隔离膜的结构示意图。
图3是根据本申请又一实施方式的隔离膜的结构示意图。
图4是根据本申请一实施方式的电池的结构示意图。
图5是根据本申请一实施方式的电池模块的结构示意图。
图6是根据本申请一实施方式的电池包的结构示意图。
图7是根据本申请一实施方式的电池包的爆炸图。
图8是根据本申请一实施方式的电池用作电源的用电装置的一个实施方式的示意图。
附图标记说明：
11：基膜；11a：基膜靠近负极极片的一侧；11b：基膜靠近正极极片的一侧；111：第一子基膜；
112：第二子基膜；12：涂层；1：电池；2：电池模块；3：电池包；4：上箱体；5：下箱体。
具体实施方式
下面结合具体实施方式，进一步阐述本申请。应理解，这些具体实施方式仅用于说明本申请而不用于限制本申请的范围。
以下，适当地参照附图详细说明具体公开了本申请的正极活性材料及其制备方法、正极极片、电池和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和/或上限的形式来限定，给定范围是通过选定一个下限和/或一个上限进行限定的，选定的下限和/或上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任意下限可以与任意上限组合形成未明确记载的范围，以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，每个单独公开的点或单个数值自身可以作为下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。例如，如果针对特定参数列出了60～120和80～110的范围，理解为60～110和80～120的范围也是预料到的。此 外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1～3、1～4、1～5、2～3、2～4和2～5。在本申请中，除非有其它说明，数值范围“a～b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0～5”表示本文中已经全部列出了“0～5”之间的全部实数，“0～5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案，并且这样的技术方案应被认为包含在本申请的公开内容中。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案，并且这样的技术方案应被认为包含在本申请的公开内容中。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。
如果没有特别的说明，在本申请中，术语“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请中，术语“多个”、“多种”是指两个或两种以上。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。除非另有说明，本申请中使用的术语具有本领域技术人员通常所理解的公知含义。除非另有说明，本申请中提到的各参数的数值可以用本领域常用的各种测量方法进行测量(例如，可以按照在本申请的实施例中给出的方法进行测试)。
随着绿色环保主题的不断推进，电池的应用已经深入到了生活的方方面面，包括车辆、电子设备、储能装置等。但随着电池应用的不断推广，人们对于电池的要求也越来越高。以锂电池为例，锂电池尤其是锂金属电池面临着循环过程中阳极锂枝晶生长的问题带来枝晶刺破隔离膜导致短路引发热失控的风险。目前，相关领域中使用较多的隔离膜通常仅能起到物理阻隔的作用，随着循环进行和枝晶生长，仍然存在枝晶沿孔隙生长刺穿的可能性。
本申请中，通过将含氟碳材料与固态电解质和金属氧化物中的一种或两种复配来形成涂层，并使涂层形成在隔膜沿其厚度方向的两侧中的至少一侧和/或隔膜中部，不仅有利于抑制枝晶生长，还能改善隔离膜的耐枝晶刺穿能力，从而可以降低枝晶刺穿隔离膜和发生电池内短路的风险。
本申请实施例公开的隔离膜适用于二次电池，并且本申请实施例公开的电池可以用于使用电池作为电源的用电设备或者使用电池作为储能元件的各种储能系统。用电设备可以包括但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、电动汽车、轮船、航天器等等。其中，电动玩具可以包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机 玩具等等，航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
本申请的第一方面提供了一种隔离膜，其包括：基膜和涂层，涂层包括含氟碳材料，以及固态电解质和/或金属氧化物，涂层设在基膜沿其厚度方向分布的两侧中的至少一侧，和/或，涂层设在基膜沿其厚度方向的中部。
本申请中，所述含氟碳材料指的具有碳-氟共价键的碳基材料，所述固态电解质指的是固体离子导体电解质。参考图1～3理解，隔离膜包括基膜11和涂层12，涂层12包括含氟碳材料，以及固态电解质和/或金属氧化物，涂层12设在基膜11沿其厚度方向分布的两侧中的至少一侧(参考图1或图2理解)，和/或，涂层12设在基膜11沿其厚度方向的中部(参考图3理解)。示例性的，涂层12可以包括含氟碳材料和固态电解质，或者可以包括含氟碳材料和金属氧化物，再或者可以同时包括含氟碳材料、固态电解质和金属氧化物。可选地，所述金属氧化物可以包括但不限于过渡金属氧化物和/或具有多种不同价态的金属的氧化物。其中，涂层的材料组成可以结合常规方法中的一种或多种分析得到，所述常规方法可以包括但不限于ICP元素分析、EDS能谱分析、XRD测试、XPS测试、红外测试、原子吸收法等，涂层的位置可以借助扫描电镜等常规仪器对隔离膜截面的微观结构进行表征得到。
本申请中，所述隔离膜可以用于锂电池或钠电池等类型的电池，其中，通过将含氟碳材料与固态电解质(通常用于制备固态电池的固态电解质层)和金属氧化物中的至少一种进行复配并在隔离膜的基膜上形成涂层，既有利于抑制枝晶的产生或生长，还能改善隔离膜的机械强度，提高其耐枝晶刺穿能力，达到较好的协同效果。以锂离子电池为例，含氟碳材料具有较高的嵌锂容量和锂反应活性，可以与Li发生反应生成C和LiF，且无中间产物，既有利于消耗锂抑制锂枝晶的产生，也可以将生成的锂枝晶反应掉，抑制锂枝晶生长(进一步地，在隔离膜朝向负极极片一侧形成所述涂层还有利于反应生成LiF界面层，有助于形成良好稳定的SEI，提高库伦效率，在高倍率下更为明显)；此外，固态电解质和金属氧化物也能与锂发生反应或具有一定的嵌锂容量，也可以消耗掉一部分锂，进而抑制锂枝晶的产生和生长；再者，固态电解质还具有较好的导离子能力，可以改善涂层的离子传输能力，进一步抑制锂枝晶的生成；进一步地，隔离膜的基膜通常为聚合物，与基膜相比，固态电解质和金属氧化物的机械强度和耐热性相对更好，且固态电解质和金属氧化物中可能存在的氧还能与含氟碳材料结合，形成更致密的涂层结构。进而，可以发挥较好的协同作用，降低枝晶刺穿隔离膜和电池内短路的风险。
本申请的隔离膜具有以下有益效果：可以抑制枝晶的生长，并改善隔离膜的耐枝晶刺穿能力，从而可以降低枝晶刺穿隔离膜和电池内短路的风险。
进一步地，本申请第一方面的隔离膜在满足上述条件的基础上，还可以可选地满足下述条件中的一个或多个。
在本申请的一些实施例中，含氟碳材料的通式可以为CFx，0.85≤x≤1.5。可选地，1≤x≤1.25。
示例性的，x的取值可以为0.85、0.9、1、1.1、1.2、1.25、1.3、1.4、1.5，等等。可选地，1≤x≤1.25。其中，CFx中x的取值可以结合红外谱图中氟碳键吸收峰面积和碳碳键吸收峰面积的相关性分析得到。含氟碳材料中氟元素含量(原子百分比)增大有利于获得提升的热稳定性。本申请中，含氟碳材料中氟元素的含量满足所给条件，有利于使涂层兼具较好的热稳定性、绝缘性和离子传导能力，从而有利于进一步改善电池的使用性能。
在本申请的一些实施例中，含氟碳材料可以包括氟化石墨、氟化炭黑、氟化碳、氟化石墨烯、氟化碳纳米管、氟化碳纤维中的一种或多种。其中氟化碳还可以包括但不限于氟化(纳米)碳纤维等，氟化石墨可以包括但不限于氟化石墨微片等。所给范围的含氟碳材料具有较高的嵌锂容量和锂反应活性，能用于锂电池或钠电池等类型的电池中来抑制枝晶成长，降低隔离膜被枝晶刺穿的风险。
在本申请的一些实施例中，含氟碳材料的粒径可以为50nm～5μm。可选地，含氟碳材料的粒径可以为50nm～1μm。
示例性的，含氟碳材料的粒径可以为50nm、100nm、200nm、500nm、800nm、1μm、2μm、3μm、4μm、5μm，等等。含氟碳材料的粒径可以结合扫描电镜、粒度分析仪等常规仪器和常规方法测得。其中，含氟碳材料的粒径增大有利于降低形成涂层时颗粒堵塞基膜微孔的风险，进而可以降低因隔离膜透气度下降引起离子传输通道阻断以及进而产生的电池容量和循环寿命下降的风险；此外，含氟碳材料的粒径增大还会增加涂层浆料粘度，采用较小粒径的含氟碳材料，不仅有利于使涂层浆料获得适宜的粘度，降低涂层浆料因粘度较大可能导致的涂层均匀性下降和涂覆难度增加的风险，还有利于改善含氟碳材料在基膜表面的附着效果，降低涂层涂覆过程中可能发生的掉粉风险。含氟碳材料的粒径满足所给范围既有利于涂层涂覆，改善涂层的均匀性和附着效果，还有利于使隔离膜兼顾较好的离子传输能力。可选地，含氟碳材料的粒径可以为50nm～1μm，由此有利于进一步兼顾涂层的均匀性和隔离膜的离子传输能力，示例性的，可以实现隔离膜的透气度≤300s/100mL，其中，隔离膜的透气度≤300s/100mL时，隔离膜的透气度较好，具有较好的离子传输特性。
在本申请的一些实施例中，含氟碳材料的体积粒径Dv50可以为50nm～1000nm。可选地，含氟碳材料的体积粒径Dv50可以为50nm～500nm。示例性的，氟碳材料的体积粒径Dv50可以为50nm、100nm、200nm、300nm、400nm、500nm、600nm、700nm、800nm、900nm、1000nm，等等。由此，有利于进一步兼顾涂层的均匀性和附着效果，并使隔离膜兼顾较好的离子传输能力。
在本申请的一些实施例中，含氟碳材料的体积粒径Dv90可以≤3μm。可选地，含氟碳材料的体积粒径Dv90可以≤1μm。示例性的，含氟碳材料的体积粒径Dv90可以为100nm～3μm、200nm～1μm、500nm～1μm、300nm、600nm、800nm、900nm、1μm、2μm、3μm，等等。由此，有利于进一步兼顾涂层的均匀性和附着效果，并使隔离膜兼顾较好的离子传输能力。
在本申请的一些实施例中，固态电解质和金属氧化物的粒径可以分别独立地为50nm～5μm。可选地，固态电解质和金属氧化物的粒径可以分别独立地为50nm～1μm，如可以分别独立地为50nm、 100nm、200nm、500nm、800nm、1μm、2μm、3μm、4μm、5μm，等等。由此有利于进一步兼顾涂层的均匀性和隔离膜的离子传输能力。
在本申请的一些实施例中，涂层的面密度可以为3.5g/m2～15g/m2。示例性的，涂层的面密度可以为3.5g/m2、4g/m2、5g/m2、6g/m2、7g/m2、8g/m2、9g/m2、10g/m2、11g/m2、12g/m2、13g/m2、14g/m2、15g/m2，等等。涂层的面密度可以通过常规方法测得，例如，可以通过测试涂层剥离前后隔离膜的重量差以及隔离膜样品的面积来计算涂层的面密度，其中涂层的剥离方法并不受特别限制，可以包括但不限于机械剥离法、溶剂浸泡法等。增大涂层厚度或涂层致密度有利于改善隔离膜的耐枝晶刺穿能力，减小涂层厚度或涂层致密度有利于获得较好的离子传输特性。涂层的面密度满足所给范围条件，既有利于降低枝晶刺穿隔离膜的风险，还有利于使隔离膜兼顾较好的离子传输能力。
在本申请的一些实施例中，涂层中含氟碳材料的面密度可以为2g/m2～14.5g/m2。示例性的，涂层中含氟碳材料的面密度可以为2g/m2、3g/m2、4g/m2、5g/m2、6g/m2、7g/m2、8g/m2、9g/m2、10g/m2、11g/m2、12g/m2、13g/m2、14g/m2、14.5g/m2，等等。涂层中含氟碳材料的面密度可以通过常规方法测得，例如，可以结合元素分析、红外测试等常规方法中的一种或多种分析得到涂层中固态电解质和/或金属氧化物与含氟碳材料的含量关系，并结合涂层的面密度计算得到。提高涂层中含氟碳材料的含量有利于通过与锂反应消耗较多的锂，改善对枝晶生长的抑制效果，提高涂层中固态电解质和/或金属氧化物的含量有利于提高隔离膜自身的强度，改善耐枝晶刺穿的能力。涂层中含氟碳材料的面密度满足所给条件，有利于进一步抑制枝晶生长，降低隔离膜被枝晶刺穿的风险。
在本申请的一些实施例中，以含氟碳材料的质量为基准，固态电解质和/或金属氧化物的总的质量百分含量可以≤70％。可选地，固态电解质和/或金属氧化物的总的质量百分含量可以为20％～50％。
示例性的，固态电解质和/或金属氧化物的总的质量百分含量可以为70％、60％、50％、40％、30％、20％、10％，等等。固态电解质和/或金属氧化物与含氟碳材料的含量关系可以结合元素分析、红外测试等常规方法中的一种或多种分析得到。提高固态电解质和/或金属氧化物的含量有利于进一步改善隔离膜的机械强度，提高隔离膜自身的耐枝晶刺穿的能力。使固态电解质和/或金属氧化物的用量满足所给范围，不仅有利于改善涂层的致密结构，并提高隔离膜自身的耐枝晶刺穿能力，还能使涂层对枝晶生长具有较好的抑制效果，同时还有利于使隔离膜兼顾较好的离子传输能力。可选地，固态电解质和/或金属氧化物的总的质量百分含量可以为20％～50％，由此有利于进一步降低隔离膜被枝晶刺穿的风险，并兼顾较好的离子传输能力。
在本申请的一些实施例中，固态电解质和金属氧化物的润湿角可以分别独立地≤15°。
示例性的，固态电解质和金属氧化物的润湿角可以分别独立地为15°、12°、10°、8°、5°，等等，或者可以分别独立地为以上任何数值所组成的范围。固态电解质和金属氧化物的润湿角可以采用常规设备和常规方法测得，例如可以采用接触角测量仪(如Dataphysics OCA25视频光学接触角测量 仪等)，将液相的水座滴在固态电解质或金属氧化物样品上，通过软件拟合图像轮廓得到其接触角值。含氟碳材料的疏水性较强，与强极性的电解液亲合较差，不利于隔离膜吸收并保持电解液，金属氧化物通常具有较好的亲水性，其表面的含氧官能团可以形成氢键改善亲水性，且受极性亲水性基团等因素影响，固态电解质通常也体现出较强的亲水性，在涂层中引入固态电解质和/或金属氧化物，还有利于隔离膜吸收并保持电解液，而使隔离膜和极片界面被电解液充分浸润在一定程度上也能改善隔离膜易被枝晶刺穿的问题。进一步地，通过使固态电解质和金属氧化物的润湿角满足所给条件，可以进一步改善隔离膜与强极性的电解液亲合性和隔离膜易被枝晶刺穿的问题。
在本申请的一些实施例中，固态电解质在25℃下的离子电导率可以≥10-4S/cm。
示例性的，固态电解质在25℃下的离子电导率可以≥10-4S/cm、≥5×10-4S/cm、≥10-3S/cm、≥5×10-3S/cm、≥10-2S/cm，等等。所述离子电导率可以采用交流阻抗法测试得到。固态电解质的离子电导率增大有利于改善隔离膜的离子传输能力。由此，满足所给条件可以进一步改善隔离膜的离子传输能力，抑制锂枝晶生长。
在本申请的一些实施例中，固态电解质可以包括氧化物电解质、硫化物电解质、酸盐电解质中的一种或多种。
本申请中，所述酸盐电解质指的是由酸盐材料(如磷酸盐、硼酸盐等常见酸盐)构成的固态电解质，可以包括但不限于磷酸盐类固态电解质材料。示例性的，以锂电池为例，所述固态电解质可以包括但不限于锂镧锆氧(LLZO)、磷酸钛铝锂(LATP)、磷酸钛锂(LTP)、磷酸锗铝锂(LAGP)、锂锗磷硫硫化物(LGPS)、四硫代磷酸锂(Li3PS4)、锂磷硫氯硫化物(Li6PS5Cl)等中的一种或多种，所给范围的固态电解质可以与含氟碳材料结合形成致密结构，或可以与锂反应消耗锂，有利于改善隔离膜的耐刺穿能力并抑制锂枝晶的生长。可选地，固态电解质可以包括但不限于Li7La3Zr2O12、Li1.4Al0.4Ti1.6(PO4)3、Li1.5Al0.5Ge1.5(PO4)3、Li1.3Al0.3Ti1.7(PO4)3、LiTi2(PO4)3、Li3PS4、Li10GeP2S12、Li6PS5Cl中的一种或多种，由此有利于进一步改善隔离膜的耐刺穿能力并抑制锂枝晶的生长。
在本申请的一些实施例中，金属氧化物的嵌锂容量可以≥600mAh/g。
示例性的，金属氧化物的嵌锂容量可以≥600mAh/g、≥650mAh/g、≥700mAh/g、≥750mAh/g、≥800mAh/g、≥850mAh/g、≥900mAh/g，等等。金属氧化物的嵌锂容量可以采用将其作为负极活性材料使用时的可逆容量表示。可将其作为负极极片的活性材料并组装电池进行充放电测试得到。较高的嵌锂容量可以消耗更多的锂，有利于进一步改善涂层对枝晶生长的抑制效果。由此，满足所给条件既可以改善隔离膜的机械强度，提高其耐刺穿能力，还有利于进一步抑制锂枝晶的生长。
在本申请的一些实施例中，金属氧化物可以包括Fe的氧化物、Sn的氧化物、Ti的氧化物、Cu的氧化物、Mn的氧化物、Al的氧化物、Ge的氧化物、Zr的氧化物、Zn的氧化物中的一种或多种。所给范围的金属氧化物具有一定的嵌锂容量或能与锂反应消耗锂，可以较好的抑制锂枝晶的生长。
在本申请的一些实施例中，涂层12还可以包括：补锂材料。针对锂电池，所述涂层会因嵌锂或与锂反应消耗少量锂，通过进一步掺入补锂材料，还有利于弥补因涂层对锂的消耗可能引起的微量容量损失。
在本申请的一些实施例中，以含氟碳材料的质量为基准，补锂材料的质量百分含量可以≤25％。
示例性的，补锂材料的质量百分含量可以为25％、23％、20％、15％、10％、5％，等等。补锂材料与含氟碳材料的相对用量可以结合元素分析、XRD测试、红外测试等常规方法确定涂层中氟化碳材料和补锂材料的具体类型和含量，并通过计算得到。针对锂电池，控制补锂材料的含量在所给范围内，不仅有利于弥补因涂层对锂的消耗可能引起的电池的微量容量损失，同时还能降低因补锂材料用量较多可能引起涂层内对锂的自消耗过多，导致对涂层外的锂的存储容量及反应能力下降，进而削弱涂层对锂枝晶生长抑制效果的风险。
在本申请的一些实施例中，补锂材料可以包括LiF、Li3N、M包覆的Li2O、LixSi包覆的Li2O中的一种或多种，M包括Fe、Co、Ni、Mn中的一种或多种，x的取值范围为0.5～3.75。
示例性的，x的取值可以为0.5、1、1.5、2、2.5、3、3.5、3.75，等等。补锂材料的具体类型可以结合元素分析、原子吸收法、XRD测试等常规方法中的一种或多种确定。所给的补锂材料有利于在较低的用量下达到较好的补锂效果，另外，采用M或LixSi包覆的Li2O既可以在Li2O表面形成钝化层，起到缓释补锂的作用，同时也能避免Li2O在加入前就因与空气接触导致的容量衰减。
在本申请的一些实施例中，涂层还包括：粘结剂、分散剂、增稠剂中的一种或多种。加入粘结剂可以提高涂层与基膜的附着强度，降低涂层中各组分可能存在的掉粉风险；加入分散剂有利于提高涂层浆料的分散均匀性，进而改善涂层的均一性；加入增稠剂有利于改善涂层浆料的稳定性，降低分层或沉降风险，改善涂层的涂覆效果和均一性。需要说明的是，所述粘结剂、所述分散剂、所述增稠剂可以分别独立地为相关领域中的常规选择，可以采用常规方法制备或商业途径得到，例如，所述粘结剂可以包括但不限于聚偏氟乙烯(PVDF)、丁苯橡胶(SBR)等其中一种或多种；所述分散剂可以包括但不限于水解聚马来酸酐、丙烯酸嵌段聚合物、聚酯嵌段聚合物、聚乙二醇型多元醇和聚乙烯亚胺衍生物等中的一种或多种；所述增稠剂可以包括但不限于羟甲基纤维素钠、甲基纤维素、羟乙基纤维素、羟丙基甲基纤维素、聚丙烯酸盐、聚氨酯、聚醚等中的一种或多种。
在本申请的一些实施例中，以涂层的质量为基准，粘结剂的质量百分含量可以为0.5％～5％。可选地，粘结剂的质量百分含量可以为1％～3％。例如，可以为0.5％、1％、2％、3％、4％、5％，等等。由此，可以有效改善涂层与基膜直接的附着强度。
在本申请的一些实施例中，以含氟碳材料的质量为基准，分散剂的质量百分含量可以≤2％。可选地，分散剂的质量百分含量可以为1％～1.5％。例如，可以为0.1％、0.5％、0.8％、1％、1.2％、1.5％、2％，等等。由此，可以有效改善涂层的均一性。
在本申请的一些实施例中，以含氟碳材料的质量为基准，增稠剂的质量百分含量可以≤2％。 可选地，增稠剂的质量百分含量可以为1％～1.5％。例如，可以为0.5％、1％、2％、3％、4％、5％，等等。由此，可以有效改善涂层涂覆的可操作性和涂层的均一性。
在本申请的一些实施例中，单层涂层的厚度可以为1.5μm～3.5μm。可选地，单层涂层的厚度可以为1.5μm～3μm。
示例性的，单层涂层的厚度可以为1.5μm、2μm、2.5μm、3μm、3.5μm，等等。涂层的厚度可以采用膜厚仪测试得到。满足所给条件不仅可以起到较好改善隔离膜强度和抑制枝晶生长的作用，提高隔离膜耐枝晶刺穿的能力，还能获得较好的可加工性，同时还能降低因涂层厚度过大可能引起的电池可逆容量损失增加以及电池能量密度下降等问题的风险。
在本申请的一些实施例中，涂层的总厚度可以≤5μm。示例性的，涂层的总厚度可以为1.5μm、2μm、2.5μm、3μm、3.5μm、4μm、4.5μm、5μm，等等。涂层的总厚度可以采用膜厚仪对各单侧涂层的厚度进行测试并计算加和得到。满足所给条件有利于在使隔离膜获得较好的耐枝晶刺穿能力的基础上，进一步降低因涂层厚度过大可能引起的电池可逆容量损失增加以及电池能量密度下降等问题的风险。
在本申请的一些实施例中，涂层的总厚度与基膜的厚度的比值可以为1：(2.5～10)。
示例性的，涂层的总厚度与基膜的厚度的比值可以为1/2.5、1/3、1/4、1/5、1/6、1/7、1/8、1/9、1/10，等等。基膜的厚度也可以采用膜厚仪测试得到。满足所给条件有利于在使隔离膜获得较好的耐枝晶刺穿能力的基础上，进一步降低因涂层厚度过大可能引起的电池可逆容量损失增加以及电池能量密度下降等问题的风险。
在本申请的一些实施例中，涂层12可以仅设在基膜11沿其厚度方向分布的两侧中的至少一侧，基膜11沿其厚度方向分布的两侧分别靠近正极极片和负极极片，基膜11靠近负极极片的一侧11a可以设有涂层12。可参考图1理解。在基膜朝向负极极片的一侧设置涂层可以进一步改善对枝晶生长的抑制效果。
在本申请的一些实施例中，涂层12可以仅设在基膜11沿其厚度方向分布的两侧中的至少一侧，设在基膜11靠近负极极片的一侧11a的涂层12的厚度可以≥设在基膜11靠近正极极片的一侧11b的涂层12的厚度。可参考图2理解。在基膜沿其厚度方向的两侧均设置涂层有利于进一步改善隔离膜的机械强度和耐刺穿能力，即便隔膜一侧被枝晶刺破也有利于延缓被彻底刺透的时间。可选地，设在基膜11靠近负极极片的一侧11a的涂层12的厚度可以大于设在基膜11靠近正极极片的一侧11b的涂层12的厚度，由此可以进一步改善对枝晶生长的抑制效果。
在本申请的一些实施例中，涂层12可以仅设在基膜11沿其厚度方向分布的两侧中的至少一侧，基膜的厚度可以≥7μm。示例性的，基膜的厚度可以为7μm、8μm、10μm、12μm、15μm等。满足所给条件有利于进一步降低被枝晶刺穿的风险。
在本申请的一些实施例中，涂层12可以仅设在基膜11沿其厚度方向的中部，位于涂层12沿 其厚度方向的两侧的基膜的厚度可以分别独立地≤9μm。可选地，位于涂层12沿其厚度方向的两侧的基膜的厚度可以分别独立地为5μm～9μm。
参考图3理解，基膜11可以包括沿其厚度方向布置的第一子基膜111和第二子基膜112，涂层12可以夹设在第一子基膜111和第二子基膜112之间。采用该设置可以避免涂层与极片直接接触，有利于在改善隔离膜耐刺穿能力的基础上降低固态电解质和/或金属氧化物与锂反应可能造成的电池容量的衰减量。进一步地，第一子基膜111和第二子基膜112的厚度可以分别独立地≤9μm，可选可以分别独立地为5μm～9μm，示例性的，第一子基膜111和第二子基膜112的厚度可以分别独立地为9μm、8μm、7μm、6μm、5μm、4μm，等等，满足所给条件有利于在降低隔离膜被枝晶刺穿的风险的基础上，进一步兼顾电池的能量密度。
在本申请的一些实施例中，涂层12可以仅设在基膜11沿其厚度方向的中部，涂层12中可以包括补锂材料，以含氟碳材料的质量为基准，补锂材料的质量百分含量可以≤10％。示例性的，补锂材料的质量百分含量可以为10％、8％、5％、3％，等等。参考图3理解，当涂层12可以夹设在第一子基膜111和第二子基膜112之间时，固态电解质和/或金属氧化物与锂的反应造成的耗锂量也较少，控制补锂材料的含量在所给范围内，不仅有利于弥补因涂层对锂的消耗可能引起的电池的微量容量损失，同时还能降低因补锂材料用量较多可能引起的涂层对锂枝晶生长抑制效果削弱的风险。
在本申请的一些实施例中，隔离膜的刺穿强度可以≥350gf。示例性的，隔离膜的刺穿强度可以≥350gf、≥400gf、≥450gf、≥500gf、≥550gf、≥650gf、≥700gf、≥750gf、≥800gf，等等。满足所给条件可以进一步降低隔离膜被枝晶刺穿的风险。可选地，隔离膜的刺穿强度可以≥450gf。
在本申请的一些实施例中，涂层在25℃下的电子电导率可以为10-6mS/cm～10-10mS/cm。由此不仅可以进一步降低涂层可能对隔离膜阻抗产生的负面影响，还能抑制电子通过隔离膜进行转移，降低电池内短路的风险。
本申请的第二方面提出了一种制备本申请第一方面的隔离膜的方法，其包括：在基膜沿其厚度方向分布的两侧中的至少一侧形成涂层；和/或，在基膜沿其厚度方向的中部形成涂层，涂层包括含氟碳材料，以及固态电解质和/或金属氧化物。采用该方法制得的隔离膜有利于抑制枝晶生长，并改善隔离膜的耐枝晶刺穿能力。
在本申请的一些实施例中，可以将包括含氟碳材料、固态电解质和/或金属氧化物、粘接剂在内的涂层原料与溶剂混合，得到涂层浆料。示例性的，可以按照预设配比，将含氟碳材料如氟化石墨粉末等均匀分散到溶剂中进行一次分散，再加入粘结剂进行二次分散。可选地，所述一次分散还可以加入分散剂，分散方法包括但不限于超声分散，其中超声时间可以根据实际情况灵活选择。再可选地，所述二次分散还可以加入增稠剂。又可选的，所述一次分散和所述二次分散可以分别独立地在搅拌条件下进行，例如，一次分散时的搅拌转速可以为700转/分～1200转/分，混合时间可以为30min～60min；二次分散时的搅拌转速可以为1000转/分～1600转/分，混合时间可以为 30min～90min。另外，所述溶剂的具体类型并不受特别限制，本领域技术人员可以根据实际需要灵活选择，例如可以包括但不限于去离子水、N-N二甲基甲酰胺(DMF)、N-N甲基吡咯烷酮(NMP)、N-N二甲基乙酰胺(DMAC)、四氢呋喃(THF)等中的一种或多种，可选地，所述涂层浆料中，溶剂的质量百分占比可以为55％～75％，再可选可以为60％～70％，满足所给条件有利于使涂层浆料具有较好的粘度和稳定性，进而有利于获得较好的涂覆效果和涂层均匀性。要说明的是，氟碳材料、固态电解质、金属氧化物、粘结剂、分散剂和增稠剂的选择和相对用量已在前述部分进行了详细说明，此处不再赘述。
在本申请的一些实施例中，可以制得涂层浆料均匀涂覆在基膜上，经烘干后得到具有涂料的隔离膜。可选地，所述涂覆包括但不限于刮涂；所述烘干条件并不受特别限制，本领域技术人员可以根据实际需要灵活选择，例如烘干温度可以为60℃～80℃，烘干时间可以为5min～30min。其中基膜厚度及涂层厚度及分布已在前述部分做了详述说明，此处不再赘述。
在本申请的一些实施例中，可以在基膜沿其厚度方向分布的两侧中的至少一侧涂覆涂层浆料，得到涂层；或者，基膜包括第一基膜和第二基膜，可以在第一基膜沿其厚度方向分布的两侧中的其中一侧涂覆涂层浆料，形成涂层，并将第二基膜叠放于涂层远离第一基膜的一侧上。其中，当在第一基膜和第二基膜中间形成涂层时，可以使位于第一基膜上的涂层于真空条件下烘干后再在将第二基膜叠放于涂层远离第一基膜的一侧上进行复合。
本申请的第三方面提出了一种电池，其包括：本申请第一方面的隔离膜，和/或采用本申请第二方面的制备隔离膜的方法制得的隔离膜。
可选地，所述电池可以为二次电池，即可以在放电后可通过充电的方式使活性材料激活而继续使用的电池。
通常情况下，电池包括正极极片、负极极片、隔离膜及电解液。在电池充放电过程中，活性离子在正极极片和负极极片之间往返嵌入和脱出。隔离膜设置在正极极片和负极极片之间，起到隔离的作用。电解质在正极极片和负极极片之间起到传导离子的作用。其中，正极极片的原料组成及结构、负极极片的原料组成及结构、隔离膜的材质和结构特征、电解液的组成等都可以为本领域的常规选择。本申请实施例对电池的类型没有特别的限制，其可以包括但不限于锂电池、钠电池等。本申请中以锂电池为例进行详细说明：
[正极极片]
正极极片通常包括正极集流体及设置在正极集流体上的正极活性物质层，正极活性物质层包括可以包括正极活性材料。正极集流体可以采用常规金属箔片或复合集流体(可以将金属材料设置在高分子基材上形成复合集流体)。作为示例，正极集流体可以包括铜箔、铝箔、镍箔、不锈钢箔、不锈钢网及涂炭铝箔中的至少一种，可选为铝箔。
正极活性材料可以为锂离子电池通常使用的正极活性材料，可以使用能可逆地嵌入与脱嵌Li+ 的化合物，例如，可以包括但不限于LixM′O2或LiyM′2O4(M为过渡金属元素，0≤x≤1，0≤y≤2)表示的含锂复合氧化物、尖晶石状的氧化物、层状结构的金属硫族化物、橄榄石结构的正极活性材料等。示例性的，可以包括但不限于LiCoO2等锂钴氧化物、LiMn2O4等锂锰氧化物、LiNiO2等锂镍氧化物、Li4/3Ti5/3O4等锂钛氧化物、锂锰镍复合氧化物、锂锰镍钴复合氧化物、具有LiM″PO4(M″包括Fe、Mn、Ni中的一种或多种)等橄榄石型结晶结构的材料等等。可选地，可以采用层状结构或尖晶石状结构的含锂复合氧化物，如LiCoO2、LiMn2O4、LiNiO2、LiNi1/2Mn1/2O2等为代表的锂锰镍复合氧化物，LiNil/3Mn1/3Co1/3O2、LiNi0.6Mn0.2Co0.2O2等为代表的锂锰镍钴复合氧化物，或LiNi1-x-y-zCoxAlyMgzO2(0≤x≤1、0≤y≤0.1、0≤z≤0.1、0≤1-x-y-z≤1)等含锂复合氧化物。另外，上述的含锂复合氧化物还可以包括但不限于掺杂Ge、Ti、Zr、Mg、Al、Mo、Sn等元素的含锂复合氧化物。还可以理解的是，所述正极活性材料，既可单独使用一种，也可多种并用，例如通过同时使用层状结构的含锂复合氧化物与尖晶石结构的含锂复合氧化物，可以兼顾大容量化和稳定性的提高。
另外，正极活性物质层中还可以适当添加炭黑、乙炔黑等导电助剂，或聚偏氟乙烯、聚环氧乙烷等粘结剂等，再可选还可以包括其它可选助剂，配制成正极浆料后将其涂覆在正极集流体上。
[负极极片]
负极极片通常包括负极集流体及设置在负极集流体上的负极活性物质层，所述负极活性物质层包括负极活性材料。所述负极集流体可以采用常规金属箔片或复合集流体(例如可以将金属材料设置在高分子基材上形成复合集流体)。作为示例，负极集流体可以采用铜箔。
负极活性材料可以为锂离子电池通常使用的负极活性材料，可以使用能够嵌入-脱嵌锂金属、锂的化合物。例如，可以包括但不限于铝、硅、锡等的合金或氧化物、碳材料等各种材料等。氧化物可以包括但不限于二氧化钛等，碳材料可以包括但不限于石墨、热解碳类、焦炭类、玻璃状碳类、有机高分子化合物的烧成体、中间相碳微珠等。
另外，负极活性物质层中还可以适当添加炭黑、乙炔黑等导电助剂，或丁苯橡胶、聚偏氟乙烯、聚环氧乙烷等粘结剂等，再可选还可以包括其它可选助剂，配制成正极浆料后将其涂覆在负极集流体上。
在本申请的一些实施例中，本申请第三方面的电池还可以为锂金属电池，此时其负极活性材料可以包括但不限于金属锂单质。例如，负极活性材料还可以是金属锂与其它各种金属或非金属元素形成的合金。
在本申请的一些实施例中，本申请第三方面的电池还可以是无负极锂金属电池，此情况下，负极可以仅由金属箔集流体组成，没有锂金属在其表面，循环过程中，仅使用正极中的锂，在负极侧以锂金属的形式析出与剥离。
[电解液]
电解液可以包括电解质盐和溶剂。
在本申请的一些实施例中，所述溶剂可以使用非水溶剂(有机溶剂)作为非水电解液。非水溶剂可以包括但不限于碳酸酯类、醚类等。
所述碳酸酯类溶剂可以包括但不限于环状碳酸酯和链状碳酸酯，环状碳酸酯可以包括但不限于碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、γ-丁内酯、硫类酯(乙二醇硫化物等)等。链状碳酸酯可以包括但不限于碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯等为代表的低粘度的极性链状碳酸酯、脂肪族支链型碳酸酯类化合物。可选地，所述碳酸酯类溶剂可以为包括环状碳酸酯(特别是碳酸乙烯酯)与链状碳酸酯的混合溶剂。
所述醚类溶剂可以包括但不限于二甲醚四甘醇(TEGDME)、乙二醇二甲醚(DME)、1，3-二氧戊烷(DOL)等中的一种或多种。
另外，除上述非水溶剂外，还可以采用丙酸甲酯等链状烷基酯类、磷酸三甲酯等链状磷酸三酯、3-甲氧基丙腈等腈类溶剂、以树枝状化合物为代表的具有醚键的支链型化合物等非水溶剂。
另外，还可以采用氟类溶剂。所述氟类溶剂可以包括但不限于H(CF2)2OCH3、C4F9OCH3、H(CF2)2OCH2CH3、H(CF2)2OCH2CF3、H(CF2)2CH2O(CF2)2H等，或可以包括但不限于CF3CHFCF2OCH3、CF3CHFCF2OCH2CH3等直链结构的(全氟烷基)烷基醚，即2-三氟甲基六氟丙基甲醚、2-三氟甲基六氟丙基乙醚、2-三氟甲基六氟丙基丙醚、3-三氟甲基八氟丁基甲醚、3-三氟甲基八氟丁基乙醚、3-三氟甲基八氟丁基丙醚、4-三氟甲基十氟戊基甲醚、4-三氟甲基十氟戊基乙醚、4-三氟甲基十氟戊基丙醚、5-三氟甲基十二氟己基甲醚、5-三氟甲基十二氟己基乙醚、5-三氟甲基十二氟己基丙醚、6-三氟甲基十四氟庚基甲醚、6-三氟甲基十四氟庚基乙醚、6-三氟甲基十四氟庚基丙醚、7-三氟甲基十六氟辛基甲醚、7-三氟甲基十六氟辛基乙醚、7-三氟甲基十六氟辛基丙醚等。可选地，上述异(全氟烷基)烷基醚与上述直链结构的(全氟烷基)烷基醚可以混用。
在本申请的一些实施例中，所述电解质盐可以包括但不限于锂的高氯酸盐、有机硼锂盐、含氟化合物的锂盐、锂酰亚胺盐等，示例性的，可以包括但不限于LiClO4、LiPF6、LiBF4、LiAsF6、LiSbF6、LiCF3SO3、LiCF3CO2、LiC2F4(SO3)2、LiN(C2F5SO2)2、LiC(CF3SO2)3、LiCnF2n+1SO3(n≥2)、LiN(RfOSO2)2(式中，Rf为氟烷基)等。可选地，所述电解质盐可以包括含氟有机锂盐，所述含氟有机锂盐由于阴离子性大且易分离成离子，在非水电解液中易溶解。进一步地，所述电解质锂盐在电解液中的浓度可以≥0.3mol/L，可选≥0.7mol/L，再可选可以≤1.7mol/L，又可选可以≤1.2mol/L，控制电解质锂盐的浓度在所给范围内，既可以获得较好离子传导能力，又有利于避免因电解质盐未能溶解完全导致电解质盐析出的问题。
在本申请的一些实施例中，电解液中还可以包括添加剂。例如添加剂可以包括负极成膜添加剂，也可以包括正极成膜添加剂，或还可以包括能够改善电池某些性能的添加剂，例如可以包括但不限于改善电池过充性能的添加剂、改善电池高温性能的添加剂、改善电池低温性能的添加剂等。
[隔离膜]
所述隔离膜采用本申请第一方面的隔离膜或采用本申请第二方面的方法制得的隔离膜，其中作为隔离膜的基膜，本申请并没有特别的限制，可以根据实际需求选用任意公知的具有电化学稳定性和力学稳定性的多孔结构膜，例如可以包括但不限于包含玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种的单层或多层薄膜。
本申请实施例对电池的形状没有特别的限制，其可以是圆柱形、方形或其它任意的形状。如图4是作为一个示例的方形结构的电池1。
在一些实施方式中，电池可包括外包装。该外包装用于封装正极极片、负极极片和电解质。
在一些实施方式中，外包装可包括壳体和盖板。其中，壳体可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体具有与容纳腔连通的开口，盖板能够盖设于所述开口，以封闭所述容纳腔。
正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件。电极组件封装于所述容纳腔。电池所含电极组件的数量可以包括一个或几个，可根据需求来调节。
在一些实施方式中，电池的外包装可以包括硬壳，例如硬塑料壳、铝壳、钢壳。
电池的外包装也可以包括软包，例如袋式软包。软包的材质可以是塑料，如可包括聚丙烯(PP)、聚对苯二甲酸丁二醇酯(PBT)、聚丁二酸丁二醇酯(PBS)中的至少一种。
在一些实施方式中，电池既可以为电池单体，也可以为由电池单体组装成的电池模块或电池包，电池模块或电池包所含电池的数量可以为多个，具体数量可根据电池模块的应用和容量来调节。
图5是作为一个示例的电池模块2。参照图5，在电池模块2中，多个电池1可以是沿电池模块2的长度方向依次排列设置。当然，也可以按照其它任意的方式进行排布。进一步可以通过紧固件将该多个电池1进行固定。
电池模块2还可以包括具有容纳空间的外壳，多个电池1容纳于该容纳空间。在一些实施方式中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以根据电池包的应用和容量进行调节。
图6和图7是作为一个示例的电池包3。参照图6和图7，在电池包3中可以包括电池箱和设置于电池箱中的多个电池模块2。电池箱包括上箱体4和下箱体5，上箱体4能够盖设于下箱体5，并形成用于容纳电池模块2的封闭空间。多个电池模块2可以按照任意的方式排布于电池箱中。
本申请的第四方面提供了一种用电装置，其包括：本申请第三方面的电池。
具体的，所述电池可以作为所述用电装置的电源，也可以作为所述用电装置的能量存储单元。所述用电装置可以包括但不限于移动设备(例如手机、笔记本电脑)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车)、电气列车、船舶及卫星、储能系统。
图8是作为一个示例的用电装置。该用电装置包括纯电动车、混合动力电动车、或插电式混合 动力电动车。作为另一个示例的用电装置可以包括手机、平板电脑、笔记本电脑。该用电设备通常要求轻薄化，可以采用电池作为电源。
以下，说明本申请的实施例。下面描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施例中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
实施例1
隔离膜的制备：
1)称量氟化石墨粉末(粒径500nm～1000nm)、Li1.3Al0.3Ti1.7(PO4)3均匀分散到N-甲基吡咯烷酮(NMP)中，并加入水解聚马来酸酐进行超声分散，超声分散2h后得到均匀的分散溶液。将分散液中加入羟甲基纤维素钠继续二次分散，再依次加入少量聚偏氟乙烯(PVDF)进行混合，得到涂层浆料。其中，氟化石墨粉末、水解聚马来酸酐、羟甲基纤维素钠和PVDF的质量比为1：0.3：0.01：0.01：0.03，其中，涂层浆料中，溶剂NMP的质量百分占比为65％。
2)将制得的涂层浆料通过凹版转移涂布的方式在孔隙率为50％、厚度为9μm的湿法PE基膜一侧涂布，涂层厚度为3μm，在60℃条件下，烘烤5min得到隔离膜。
性能测试：
1)隔离膜的穿刺强度测试：参照GB/T 36363-2018锂离子电池用聚烯烃隔膜要求，将隔离膜平展于夹具中并夹紧，以(100+10)mm/min的速率进行穿刺，完毕后取出试样，按照GB/T 6672-2001的规定，在针孔的四周进行4点厚度的测试，取平均值，并计算穿刺强度。
2)隔离膜的拉伸强度测试(TD(横向)&MD(纵向)方向)：参照GB/T 36363-2018锂离子电池用聚烯烃隔膜要求进行。
3)隔离膜的热收缩率测试(TD&MD方向)：参照GB/T 36363-2018锂离子电池用聚烯烃隔膜要求进行。
4)隔离膜透气度测试：参照GB/T36363-2018的标准进行。
实施例2～19及对比例1～3
实施例2～19及对比1～3与实施例1的区别详见表1。其中，实施例2～19及对比例1～3中，涂层中含氟碳材料、固态电解质和金属氧化物的总质量不变。
实施例20～24及对比例4～5
实施例20～24及对比4～5与实施例1的区别详见表2。
对实施例1～24及对比例1～5的隔离膜和扣式电池进行相关测试，测试结果见表1和表2。

结论：
综合实施例1～19及对比例1～3、表1可知，将固态电解质和/或金属氧化物与含氟碳材料混合制备隔离膜涂层，可以明显改善隔离膜的耐刺穿强度。进一步地，适当提高隔离膜的涂层的厚度，或适当提高涂层中固态电解质和/或金属氧化物相对于含氟碳材料的含量，对于促进隔离膜的耐刺穿强度具有正向促进作用。再者，在隔离膜沿其厚度方向的两侧或中间设置所述涂层，均有利于改善隔离膜的耐刺穿强度。此外，结合实施例20～24及对比例4～5可知，相对于未设置所述涂层，设置所述涂层可以改善隔离膜的拉伸强度及热收率，分析原因主要在于，涂层作为加强材料能降低应变，防止拉伸或热收缩过程中基膜结构被破坏；另外，设置涂层后隔离膜的透气度虽有一定影响，但整体透气度仍处于较好水平，可以发挥较好的离子传输特性；进一步地，适当增大含氟碳材料的粒径对改善隔离膜的透气度具有正向促进作用，适当减小含氟碳材料的粒径对改善隔离膜的拉伸强度及热收率有促进作用，使含氟碳材料的粒径在合理范围内有利于同时兼顾隔离膜的透气度、力学强度及热收缩率。
最后应说明的是：以上各实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述各实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的范围，其均应涵盖在本申请的权利要求和说明书的范围当中。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (25)

  1. 一种隔离膜，其中，包括：基膜和涂层，所述涂层包括含氟碳材料，以及固态电解质和/或金属氧化物，所述涂层设在所述基膜沿其厚度方向分布的两侧中的至少一侧，和/或，所述涂层设在所述基膜沿其厚度方向的中部。
  2. 根据权利要求1所述的隔离膜，其中，所述含氟碳材料的通式为CFx，0.85≤x≤1.5。
  3. 根据权利要求1或2所述的隔离膜，其中，满足以下条件中的一个或多个：
    (1)所述含氟碳材料包括氟化石墨、氟化炭黑、氟化碳、氟化石墨烯、氟化碳纳米管、氟化碳纤维中的一种或多种；
    (2)所述含氟碳材料的粒径为50nm～5μm；
    (3)所述含氟碳材料的体积粒径Dv50为50nm～1000nm；
    (4)所述含氟碳材料的体积粒径Dv90≤3μm。
  4. 根据权利要求1～3中任一项所述的隔离膜，其中，满足以下条件中的一个或多个：
    (a)所述含氟碳材料的通式为CFx，1≤x≤1.25；
    (b)所述含氟碳材料的粒径为50nm～1μm；
    (c)所述含氟碳材料的体积粒径Dv50为50nm～500nm；
    (d)所述含氟碳材料的体积粒径Dv90≤1μm。
  5. 根据权利要求1～4中任一项所述的隔离膜，其中，所述涂层的面密度为3.5g/m2～15g/m2；和/或，所述涂层中含氟碳材料的面密度为2g/m2～14.5g/m2。
  6. 根据权利要求1～5中任一项所述的隔离膜，其中，以所述含氟碳材料的质量为基准，所述固态电解质和/或所述金属氧化物的总的质量百分含量≤70％。
  7. 根据权利要求1～6中任一项所述的隔离膜，其中，所述固态电解质和所述金属氧化物的润湿角分别独立地≤15°。
  8. 根据权利要求1～7中任一项所述的隔离膜，其中，所述固态电解质在25℃下的离子电导率≥10-4S/cm；和/或，所述金属氧化物的嵌锂容量≥600mAh/g。
  9. 根据权利要求1～8中任一项所述的隔离膜，其中，所述固态电解质包括氧化物电解质、硫化物电解质、酸盐电解质中的一种或多种；和/或，
    所述金属氧化物包括Fe的氧化物、Sn的氧化物、Ti的氧化物、Cu的氧化物、Mn的氧化物、Al的氧化物、Ge的氧化物、Zr的氧化物、Zn的氧化物中的一种或多种。
  10. 根据权利要求1～9中任一项所述的隔离膜，其中，以所述含氟碳材料的质量为基准，所述固态电解质和/或所述金属氧化物的总的质量百分含量为20％～50％；和/或，
    所述固态电解质包括Li7La3Zr2O12、Li1.4Al0.4Ti1.6(PO4)3、Li1.5Al0.5Ge1.5(PO4)3、Li1.3Al0.3Ti1.7(PO4)3、 LiTi2(PO4)3、Li3PS4、Li10GeP2S12、Li6PS5Cl中的一种或多种。
  11. 根据权利要求1～10中任一项所述的隔离膜，其中，所述涂层还包括：补锂材料。
  12. 根据权利要求11所述的隔离膜，其中，以所述含氟碳材料的质量为基准，所述补锂材料的质量百分含量≤25％；和/或，
    所述补锂材料包括LiF、Li3N、M包覆的Li2O、LixSi包覆的Li2O中的一种或多种，M包括Fe、Co、Ni、Mn中的一种或多种，x的取值范围为0.5～3.75。
  13. 根据权利要求1～12中任一项所述的隔离膜，其中，所述涂层还包括：粘结剂、分散剂、增稠剂中的一种或多种。
  14. 根据权利要求13所述的隔离膜，其中，以所述涂层的质量为基准，所述涂层满足以下条件中的一个或多个：
    (I)所述粘结剂的质量百分含量为0.5％～5％；
    (II)所述分散剂的质量百分含量≤2％；
    (III)所述增稠剂的质量百分含量≤2％。
  15. 根据权利要求13或14所述的隔离膜，其中，以所述涂层的质量为基准，所述涂层满足以下条件中的一个或多个：
    (i)所述粘结剂的质量百分含量为1％～3％；
    (ii)所述分散剂的质量百分含量为1％～1.5％；
    (iii)所述增稠剂的质量百分含量为1％～1.5％。
  16. 根据权利要求1～15中任一项所述的隔离膜，其中，满足以下条件中的一个或多个：
    (A)单层所述涂层的厚度为1.5μm～3.5μm；
    (B)所述涂层的总厚度≤5μm；
    (C)所述涂层的总厚度与所述基膜的厚度的比值为1：(2.5～10)。
  17. 根据权利要求1～16中任一项所述的隔离膜，其中，所述涂层仅设在所述基膜沿其厚度方向分布的两侧中的至少一侧，并满足以下条件中的一个或多个：
    (一)所述基膜沿其厚度方向分布的两侧分别靠近正极极片和负极极片，所述基膜靠近负极极片的一侧设有所述涂层；
    (二)设在所述基膜靠近所述负极极片的一侧的所述涂层的厚度≥设在所述基膜靠近所述正极极片的一侧的所述涂层的厚度；
    (三)所述基膜的厚度≥7μm。
  18. 根据权利要求1～16中任一项所述的隔离膜，其中，所述涂层仅设在所述基膜沿其厚度方向的中部，并满足以下两个条件中的一个或两个：
    (α)位于所述涂层沿其厚度方向的两侧的所述基膜的厚度分别独立地≤9μm；
    (β)所述涂层中包括补锂材料，以所述含氟碳材料的质量为基准，所述补锂材料的质量百分含量≤10％。
  19. 根据权利要求18所述的隔离膜，其中，位于所述涂层沿其厚度方向的两侧的所述基膜的厚度分别独立地为5μm～9μm。
  20. 根据权利要求1～19中任一项所述的隔离膜，其中，所述隔离膜的刺穿强度≥350gf；和/或，所述涂层在25℃下的电子电导率为10-6mS/cm～10-10mS/cm。
  21. 根据权利要求1～20中任一项所述的隔离膜，其中，单层所述涂层的厚度为1.5μm～3μm；和/或，所述隔离膜的刺穿强度≥450gf。
  22. 一种制备权利要求1～21中任一项所述的隔离膜的方法，其中，包括：
    在基膜沿其厚度方向分布的两侧中的至少一侧形成涂层；和/或，在所述基膜沿其厚度方向的中部形成所述涂层，所述涂层包括含氟碳材料，以及固态电解质和/或金属氧化物。
  23. 根据权利要求22所述的方法，其中，包括：
    将包括含氟碳材料、固态电解质和/或金属氧化物、粘接剂在内的涂层原料与溶剂混合，得到涂层浆料；
    在所述基膜沿其厚度方向分布的两侧中的至少一侧涂覆所述涂层浆料，得到所述涂层；或者，所述基膜包括第一基膜和第二基膜，在所述第一基膜沿其厚度方向分布的两侧中的其中一侧涂覆所述涂层浆料，形成所述涂层，并将所述第二基膜叠放于所述涂层远离所述第一基膜的一侧上。
  24. 一种电池，其中，包括：权利要求1～21中任一项所述的隔离膜，和/或采用权利要求22或23所述的方法制得的隔离膜。
  25. 一种用电装置，其中，包括：权利要求24所述的电池。
PCT/CN2024/092042 2023-11-30 2024-05-09 隔离膜及其制备方法、电池和用电装置 Pending WO2025112293A1 (zh)

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