WO2024221900A1 - 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

Info

Publication number
WO2024221900A1
WO2024221900A1 PCT/CN2023/134693 CN2023134693W WO2024221900A1 WO 2024221900 A1 WO2024221900 A1 WO 2024221900A1 CN 2023134693 W CN2023134693 W CN 2023134693W WO 2024221900 A1 WO2024221900 A1 WO 2024221900A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
monomer
intermediate layer
temperature
inorganic filler
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2023/134693
Other languages
English (en)
French (fr)
Inventor
宋少康
薛文文
刘成勇
何晓宁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Publication of WO2024221900A1 publication Critical patent/WO2024221900A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/417—Polyolefins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/423—Polyamide resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H01M50/426—Fluorocarbon polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • H01M50/491—Porosity
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of battery technology, and in particular, to an isolation membrane and a preparation method thereof, a battery and an electrical device.
  • the separator is one of the key internal structures.
  • the separator plays the role of isolating the positive and negative electrodes to prevent the positive and negative electrodes from short-circuiting.
  • the separator also needs to conduct ions.
  • the current separator has poor stability at high temperatures, resulting in the risk of thermal runaway of the battery.
  • the present application aims to alleviate or solve at least one of the above-mentioned problems to at least some extent.
  • the present application proposes an isolation membrane.
  • the isolation membrane includes: a first substrate, and an intermediate layer located on at least one side of the first substrate, the porosity of the isolation membrane at the first temperature is a, the porosity of the isolation membrane at the second temperature is b, the first temperature is -20°C ⁇ 100°C, 40% ⁇ a ⁇ 70%, the second temperature is not less than 120°C, b ⁇ 2%.
  • the isolation membrane has a higher porosity at a lower temperature, which is conducive to the passage of ions; at a higher temperature, the porosity of the isolation membrane is significantly reduced, and the pores of the isolation membrane are blocked, which can at least isolate ion conduction to a certain extent, thereby alleviating the continuous temperature rise caused by the exchange of positive and negative ions at a higher temperature, thereby reducing the probability of thermal runaway of the battery.
  • the third temperature is -20°C to 120°C.
  • the intermediate layer includes a first monomer, and the first monomer satisfies at least one of the following conditions: the molecule of the first monomer contains a ring structure, the number of atoms of the ring structure is less than or equal to 7, and the ring structure has a first functional group; the molecular weight of the first monomer is not less than 90; and the polymerization temperature of the first monomer is not less than 120°C.
  • the first monomer is less likely to undergo polymerization reaction at a lower temperature, so that the isolation membrane can maintain a higher porosity, which is conducive to the conduction of ions.
  • the mass content of the first monomer is 0.1wt%-20wt%.
  • the isolation membrane contains an appropriate amount of the first monomer, and the first monomer polymerizes at a higher temperature, which can significantly reduce the porosity of the isolation membrane, thereby improving the thermal stability of the isolation membrane.
  • the intermediate layer further includes an inorganic filler, and the inorganic filler satisfies at least one of the following conditions: the inorganic filler includes an inert inorganic filler, and the inert inorganic filler includes at least one of silicon dioxide, titanium dioxide, zinc oxide, zirconium oxide, magnesium oxide, barium oxide, aluminum oxide, barium titanate and magnesium hydroxide; the inorganic filler includes an active inorganic filler, and the active inorganic filler includes at least one of garnet-type solid electrolyte, perovskite-type solid electrolyte, antiperovskite-type solid electrolyte, sodium superion conductor-type solid electrolyte and lithium phosphorus nitrogen oxide-type solid electrolyte; the surface of the inorganic filler has a second functional group, and the second functional group includes at least one of amino, epoxy, carbon-carbon double bond, aldehyde, hydroxyl, furfuryl, imide and
  • the inorganic filler has a mass content of 1wt%-20wt% based on the total mass of the isolation membrane.
  • the inorganic filler in the above content can significantly improve the thermal shrinkage and puncture resistance of the isolation membrane, and will not cause significant adverse effects on ion conduction.
  • the intermediate layer further includes an oligomer, the oligomer contains a stable free radical, and the oligomer satisfies at least one of the following conditions: the oligomer is a polymer composed of 2-20 repeating units; the molecular weight of the oligomer is 200-10000; the stable free radical includes at least one of trityl, nitro and nitrogen oxide free radicals.
  • the stable free radical contained in the oligomer can react with the first monomer at a higher temperature, so that the first monomer polymerizes faster, thereby reducing the porosity of the isolation membrane at a higher temperature.
  • the nitrogen oxide free radical includes at least one of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl monomer, poly-2,2,6,6-tetramethylpiperidine-4-methylacrylate-1-nitroxide free radical and 2,2,6,6-tetramethyl-piperidine nitroxide free radical.
  • the oligomer includes at least one of a polythiophenylphenoxy polymer, an aromatic methyl radical polymer, a nitroxide radical functionalized polyacrylamine dendrimer, a conjugated radical polymer, a comb-like nitroxide radical polymer, a polyethyleneamine-loaded nitroxide radical polymer, and a polyethyleneamine-loaded nitro radical polymer.
  • the mass content of the oligomer is 0.1 wt%-10 wt%.
  • the oligomer can rapidly polymerize the first monomer and rapidly reduce the porosity of the isolation membrane.
  • the isolation film further includes a second substrate, which is located on a side of the intermediate layer away from the first substrate.
  • the second substrate can cooperate with the first substrate to cover the intermediate layer to form a film layer with a stable structure.
  • the first substrate and the second substrate each independently include polyamide, polyamideimide, polyketone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl chloride, At least one of polyolefin, perfluoroalkoxyalkane, polyester, liquid crystal polymer, polyoxymethylene, acrylonitrile styrene acrylate, styrene acrylonitrile, acrylonitrile butadiene styrene, polybenzimidazole, polyparaphenylene copolymer, polyacrylonitrile, polyethyleneimine, ethylene tetrafluoroethylene, polychlorotrifluoroethylene, aramid, polyetherimide, polyparaphenylene benzobisoxazole and cellulose.
  • both the first substrate and the second substrate have good electronic insulation properties, can better isolate the positive electrode and the negative electrode, have good ion conductivity, can conduct ions during the charge and discharge process; and have a certain mechanical strength, can resist dendrite piercing to a certain extent.
  • the present application proposes a method for preparing the aforementioned isolation membrane.
  • the method for preparing the aforementioned isolation membrane includes: providing a first substrate; preparing an intermediate layer precursor solution, wherein the intermediate layer precursor solution includes an electrolyte and a first monomer; coating the intermediate layer precursor solution on at least one side surface of the first substrate to form an intermediate layer precursor solution coating layer, and performing a heat treatment to obtain an isolation membrane.
  • the isolation membrane prepared has all the characteristics and advantages of the isolation membrane described above, which will not be described in detail here; the method is simple to operate, easy to implement, and is conducive to improving product yield.
  • the method for preparing the aforementioned isolation film further comprises: arranging a second substrate on a side of the intermediate layer precursor coating layer away from the first substrate.
  • the second substrate can cooperate with the first substrate to fix the intermediate layer precursor coating layer.
  • the intermediate layer precursor solution further includes at least one of an inorganic filler, an oligomer, a second monomer, and an initiator.
  • the inorganic filler has good thermal stability, which is beneficial to improving the thermal stability of the isolation membrane; the oligomer can react with the first monomer at a higher temperature to quickly reduce the porosity of the isolation membrane; the second monomer can be cured at a lower temperature; the initiator can induce micro-crosslinking and curing of some components in the intermediate layer precursor solution, so that the intermediate layer precursor solution coating layer quickly forms an intermediate layer.
  • the method for preparing the aforementioned isolation film satisfies at least one of the following conditions: the electrolyte includes ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide lithium salt; the second monomer includes pentaerythritol triacrylate; the temperature of the heating treatment is 60°C-70°C; the time of the heating treatment is 1h-20h.
  • the electrolyte can play a role in conducting lithium ions; the temperature or time of the heating treatment is set within the above range, so that some components in the intermediate layer precursor solution can be micro-crosslinked and cured to obtain an isolation film with excellent performance.
  • the present application proposes a battery.
  • the battery includes a positive electrode sheet, a negative electrode sheet, and a separator between the positive electrode sheet and the negative electrode sheet, and the separator includes the aforementioned separator.
  • the battery has all the features and advantages of the aforementioned separator, which will not be repeated here.
  • the battery has good thermal stability and a low probability of thermal runaway.
  • the present application provides an electrical device.
  • the electrical device includes the battery described above. Therefore, the electrical device has all the features and advantages of the battery described above, which will not be repeated here.
  • FIG1 shows a schematic structural diagram of an isolation membrane according to an embodiment of the present application
  • FIG2 shows a schematic structural diagram of an isolation membrane according to another embodiment of the present application.
  • FIG3 shows a schematic structural diagram of an isolation membrane according to another embodiment of the present application.
  • FIG4 shows a schematic structural diagram of an isolation membrane according to another embodiment of the present application.
  • FIG5 shows a schematic structural diagram of a battery according to an embodiment of the present application.
  • FIG6 shows an exploded view of the battery in FIG5 ;
  • FIG7 shows a schematic structural diagram of a battery module according to an embodiment of the present application.
  • FIG8 shows a schematic structural diagram of a battery pack according to an embodiment of the present application.
  • FIG9 shows an exploded view of the battery pack in FIG8 ;
  • FIG. 10 shows a schematic diagram of the structure of an electrical device using a battery as a power source according to an embodiment of the present application.
  • 100 isolation film; 110: first substrate; 120: intermediate layer; 130: second substrate; 1: battery pack; 2: upper case; 3: lower case; 4: battery module; 5: battery; 51: housing; 52: electrode assembly; 53: cover plate.
  • any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and any upper limit can be combined with any other upper limit to form an unspecified range.
  • each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.
  • the separator plays the role of isolating the positive and negative electrodes and conducting ions.
  • the separator At a higher temperature, if the separator continues to conduct ions, the exchange of positive and negative ions at high temperature may cause continuous temperature rise, resulting in the risk of thermal runaway of the battery.
  • the separator By setting an intermediate layer on one side of the separator substrate, the separator has a higher porosity at a lower temperature and can better conduct ions during the charge and discharge process.
  • the separator has a lower porosity at a higher temperature, which can hinder the conduction of ions at high temperature, thereby alleviating the problem of continuous temperature rise caused by the exchange of positive and negative ions at high temperature, and thus reducing the risk of thermal runaway of the battery.
  • the separator can be applied to a liquid electrolyte battery or a semi-solid electrolyte battery.
  • the separator can be applied to a liquid electrolyte lithium-ion battery, a semi-solid electrolyte lithium-ion battery, and the like.
  • the battery disclosed in the embodiments of the present application can be used in an electrical device that uses the battery as a power source or in various energy storage systems that use the battery as an energy storage element.
  • the electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like.
  • the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like
  • the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.
  • the present application provides an isolation film.
  • the isolation film 100 may include a first substrate 110 and an intermediate layer 120 located on at least one side of the first substrate 110 .
  • the porosity of the isolation membrane 100 at the first temperature is a
  • the porosity of the isolation membrane 100 at the second temperature is b.
  • the first temperature can be -20°C ⁇ 100°C, 40% ⁇ a ⁇ 70%.
  • the first temperature can be -20°C, -10°C, -5°C, 0°C, 10°C, 30°C, 50°C, 80°C, 100°C, etc.
  • a can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, etc.
  • the second temperature can be not less than 120°C, b ⁇ 2%.
  • the second temperature can be 120°C, 130°C, 150°C, 170°C, etc., and b can be 0.2%, 0.5%, 1%, 1.5%, 1.8%, 2%, etc.
  • the term "porosity” refers to the percentage of the total volume of pores in the separator to the total volume of the separator in its natural state.
  • the separator has a larger porosity, and the separator can play a better role in ion conduction during the charge and discharge process; at higher temperatures, some components in the middle layer will undergo polymerization, which will reduce the porosity of the separator and increase the internal resistance of the battery, which can at least isolate ion conduction to a certain extent, thereby effectively alleviating or even solving the problem of continuous temperature rise caused by positive and negative ion exchange at higher temperatures, thereby reducing the probability of thermal runaway of the battery and helping to improve the thermal stability of the battery.
  • one surface of the first substrate 110 may be provided with an intermediate layer 120.
  • both surfaces of the first substrate 110 may be provided with intermediate layers 120.
  • the isolation film 100 may further include a second substrate 130, and the second substrate 130 is located on a side of the intermediate layer 120 away from the first substrate 110.
  • the second substrate can cooperate with the first substrate to firmly cover the intermediate layer, thereby facilitating the improvement of the structural stability of the isolation film.
  • the isolation film 100 includes a first substrate 110, an intermediate layer 120, and a second substrate 130 stacked in sequence.
  • the intermediate layer 120 is disposed on both surfaces of the first substrate 110, and the second substrate 130 is disposed on the surface of each intermediate layer 120 away from the first substrate 110.
  • the first substrate 110 and the second substrate 130 may each independently include at least one of polyamide (PA), polyamideimide (PAI), polyketone, polysulfone (PSU), polyphenylene sulfide (PPS), polyphenylene ether (PPE), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), polyolefin, perfluoroalkoxyalkane (PFA), polyester, liquid crystal polymer (LCP), polyoxymethylene (POM), acrylonitrile styrene acrylate (ASA), styrene acrylonitrile (SAN), acrylonitrile butadiene styrene (ABS), polybenzimidazole (PBI), polyparaphenylene copolymer (PPP), polyacrylonitrile, polyethyleneimine, ethylene tetrafluoroethylene (ETFE), polychlorotrifluoro
  • the first substrate 110 and the second substrate 130 can each independently be composed of one of the above materials; in some embodiments of the present application, the first substrate 110 and the second substrate 130 can each independently be composed of two or more of the above materials.
  • the above materials have a certain strength and can provide a good support for the intermediate layer; the above materials all have good electronic insulation properties and good ion conductivity properties, and can play the role of isolating the positive electrode and the negative electrode and conducting ions.
  • the polyparaphenylene copolymer may include at least one of a polyparaphenylene vinylene copolymer, a polyparaphenylene ethylene copolymer, and the like.
  • the first substrate and the second substrate may each independently include a polyketone, for example, polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneetherketoneketone (PEKEKK), and the like.
  • PEK polyetherketone
  • PEEK polyetheretherketone
  • PEKEKK polyetherketoneetherketoneketone
  • the first substrate and the second substrate may each independently include polyamide, for example, polyamide 46 (PA46), polyamide 66 (PA66), polyamide 12 (PA12), polyamide 11 (PA11), polyamide 6 (PA6), polyamide 6.6 (PA6.6), polyamide 6.6/6 (PA6.6/6), amorphous polyamide (PA6-3-T), polyphthalamide (PPA), etc.
  • polyamide 46 PA46
  • PA66 polyamide 66
  • PA66 polyamide 12
  • PA11 PA11
  • PA6 polyamide 6.6
  • PA6.6/6 PA6.6/6
  • PA6-3-T polyphthalamide
  • PPA polyphthalamide
  • the first substrate and the second substrate may each independently include polysulfone, for example, polyphenylsulfone (PPSU), polyethersulfone (PES), and the like.
  • PPSU polyphenylsulfone
  • PES polyethersulfone
  • the first substrate and the second substrate may each independently include polyester, for example, polyethylene terephthalate (PET), polycarbonate (PC), polybutylene terephthalate (PBT), polymethyl methacrylate (PMMA), etc.
  • PET polyethylene terephthalate
  • PC polycarbonate
  • PBT polybutylene terephthalate
  • PMMA polymethyl methacrylate
  • the first substrate and the second substrate may each independently include polyolefins, for example, polypropylene (PP), polyethylene (PE), high-density polyethylene (HDPE), polymethylpentene (PMP), and the like.
  • polypropylene PP
  • PE polyethylene
  • HDPE high-density polyethylene
  • PMP polymethylpentene
  • the first substrate and the second substrate may each independently include aramid, for example, thienyl aramid, pyrrolyl aramid, furanyl aramid, and the like.
  • the first substrate and the second substrate can each independently include at least one of polyimide, polypropylene, aramid, thienyl aramid, pyrrolyl aramid, furanyl aramid, pyridine polyamide, polyamideimide, polyetherimide, polysulfone, polyketone, polyparaphenylene benzobisoxazole and cellulose.
  • the above materials have good high-temperature shrinkage resistance and a smaller shrinkage rate at higher temperatures, which can reduce the risk of short circuit between the positive and negative electrodes at higher temperatures.
  • the intermediate layer may include a first monomer.
  • “Monomer” refers to a small molecule that is capable of polymerizing with other molecules of the same or other species.
  • the molecule of the first monomer may contain a cyclic structure, the number of atoms in the cyclic structure is less than or equal to 7, and the cyclic structure has a first functional group. Therefore, the first monomer has a large steric hindrance, the reaction activity of the first monomer is low, it is not easy to undergo polymerization reaction at a low temperature, and it is not easy to block the pores of the isolation membrane.
  • the first functional group may include but is not limited to a carbon-oxygen double bond, a hydrocarbon functional group (e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, vinyl, propenyl, etc.), a carboxyl group, an ether bond, a carbonyl group, etc.
  • a hydrocarbon functional group e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, vinyl, propenyl, etc.
  • the first monomer may include maleic anhydride, the molecule of maleic anhydride contains a ring structure, the number of atoms in the ring structure of maleic anhydride is 5, and the ring structure has a first functional group carbon-oxygen double bond.
  • the monomer has a large steric hindrance, a low reaction activity, and is not easy to undergo polymerization reaction at a low temperature.
  • the first functional group on the ring structure does not include a functional group formed only by the atoms constituting the ring.
  • the carbon-carbon double bond and carbon-oxygen single bond in maleic anhydride do not belong to the first functional group on the ring structure of maleic anhydride.
  • steric hindrance refers to the mutual repulsion caused by the spatial arrangement of groups within a molecule.
  • the aforementioned monomer has a large steric hindrance, which has a great influence on the reactivity of the monomer.
  • the cyclic structure of the first monomer molecule may contain at least one heteroatom such as a nitrogen atom and an oxygen atom.
  • the molecular weight of the first monomer is not less than 90, and thus the first monomer has a relatively large molecular weight, and the first monomer mixture is relatively viscous and difficult to polymerize.
  • the polymerization temperature of the first monomer is not less than 120° C., so that the first monomer is less likely to undergo polymerization reaction at a relatively low temperature, which is beneficial to the conduction of ions.
  • the mass content of the first monomer can be 0.1wt%-20wt%.
  • the mass content of the first monomer can be 0.1wt%, 0.5wt%, 1wt%, 5wt%, 10wt%, 15wt%, 20wt%, etc., thereby, the isolation membrane contains an appropriate amount of the first monomer, and the first monomer is not easy to block the pores of the isolation membrane at a lower temperature, and the isolation membrane has better ion conductivity at a lower temperature; at a higher temperature, the first monomer will undergo a polymerization reaction, blocking the pores, thereby reducing the porosity of the isolation membrane and isolating ion conduction, thereby alleviating the problem of continuous temperature rise caused by the exchange of positive and negative ions at high temperature, and reducing the probability of thermal runaway of the battery.
  • the middle layer may further include inorganic fillers.
  • Inorganic fillers have good strength, which is conducive to improving the puncture resistance of the isolation membrane; inorganic fillers have good thermal stability, which is conducive to reducing the thermal shrinkage rate of the isolation membrane, thereby improving the thermal stability of the isolation membrane.
  • the inorganic filler may include an inert inorganic filler and/or an active inorganic filler, wherein the inert inorganic filler includes at least one of silicon dioxide, titanium dioxide, zinc oxide, zirconium oxide, magnesium oxide, barium oxide, aluminum oxide, barium titanate and magnesium hydroxide; the active inorganic filler includes at least one of a garnet-type solid electrolyte, a perovskite-type solid electrolyte, an antiperovskite-type solid electrolyte, a sodium superion conductor (NASICON)-type solid electrolyte and a lithium phosphorus nitrogen oxide (LiPON)-type solid electrolyte.
  • the inert inorganic filler includes at least one of silicon dioxide, titanium dioxide, zinc oxide, zirconium oxide, magnesium oxide, barium oxide, aluminum oxide, barium titanate and magnesium hydroxide
  • the active inorganic filler includes at least one of a garnet-type solid electrolyte, a
  • the above-mentioned inorganic filler may have good thermal stability, and may improve the thermal stability of the isolation membrane at least to a certain extent, and the above-mentioned inorganic filler has high strength, and may improve the puncture resistance of the isolation membrane; the above-mentioned active inorganic filler may also promote ion conduction during the charge and discharge process.
  • the surface of the inorganic filler has a second functional group
  • the second functional group on the surface of the inorganic filler may include at least one of an amino group, an epoxy group, a carbon-carbon double bond, an aldehyde group, a hydroxyl group, a furfuryl group, an imide group, and an isocyanate group.
  • the second functional group on the surface of the inorganic filler can undergo a self-polymerization reaction or react with the first monomer at a higher temperature, thereby blocking the pores in the isolation membrane, reducing the porosity of the isolation membrane at a higher temperature, thereby reducing the conduction of positive and negative ions, and further alleviating the problem of continuous temperature rise caused by the exchange of positive and negative ions at high temperatures, and reducing the probability of thermal runaway of the battery.
  • the mass content of the inorganic filler can be 1wt%-20wt%.
  • the mass content of the inorganic filler can be 1wt%, 5wt%, 10wt%, 15wt%, 20wt%, etc.
  • the above content of inorganic filler can at least improve the thermal stability and puncture resistance of the isolation membrane to a certain extent.
  • the intermediate layer further includes an oligomer, and the oligomer contains stable free radicals. Therefore, the stable free radicals of the oligomer can react with the first monomer at a higher temperature, causing the first monomer to polymerize faster, blocking the pores of the isolation membrane, thereby isolating the conduction of ions and alleviating the problem of continuous temperature rise caused by positive and negative ion exchange at a higher temperature.
  • the oligomer is a polymer composed of 2-20 repeating units, and thus the oligomer is not likely to block pores at lower temperatures and has no significant adverse effect on the conduction of ions at lower temperatures.
  • the molecular weight of the oligomer is 200-10000.
  • the molecular weight of the oligomer is relatively low, and the oligomer is less likely to block pores at relatively low temperatures.
  • the stable free radicals may include at least one of trityl, nitro and nitrogen oxide free radicals, etc.
  • the above stable free radicals can react with the first monomer at a higher temperature to polymerize the first monomer faster, thereby quickly blocking the pores of the isolation membrane.
  • the nitrogen oxide free radicals may include at least one of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl monomer, poly-2,2,6,6-tetramethylpiperidine-4-methylacrylate-1-nitroxide free radical and 2,2,6,6-tetramethyl-piperidine nitroxide free radical, whereby, at higher temperatures, the above-mentioned free radicals can promote faster polymerization of the first monomer and block the pores.
  • the oligomer may include at least one of a polythienylphenoxy polymer, an arylmethyl radical polymer, a nitroxide radical functionalized polyacrylamine dendrimer, a conjugated radical polymer, a comb-like nitroxide radical polymer, a polyethyleneamine-supported nitroxide radical polymer, and a polyethyleneamine-supported nitro radical polymer.
  • the above oligomers may react with the first monomer to promote rapid polymerization of the first monomer, thereby rapidly reducing the porosity of the isolation membrane and isolating the conduction of ions.
  • the mass content of the oligomer can be 0.1wt%-10%wt.
  • the mass content of the oligomer can be 0.1wt%, 0.5wt%, 1wt%, 5wt%, 10%wt, etc.
  • the isolation membrane contains an appropriate amount of oligomers, which can promote the polymerization of the first monomer at a higher temperature, quickly block the pores, and reduce the conduction of ions; at a lower temperature, the above-mentioned content of oligomers has no obvious adverse effect on the conduction of ions.
  • the present application proposes a method for preparing the aforementioned isolation film.
  • the method for preparing the aforementioned isolation film may include the following steps:
  • an intermediate layer precursor solution is prepared, wherein the intermediate layer precursor solution may include an electrolyte and a first monomer.
  • the electrolyte may include carbonates, such as ethyl carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), propylene carbonate (PC), ethyl methyl carbonate (EMC), etc., and the above electrolytes can assume the ion conduction function in the intermediate layer.
  • carbonates such as ethyl carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), propylene carbonate (PC), ethyl methyl carbonate (EMC), etc.
  • the electrolyte may further include fluoroethylene carbonate. Adding fluoroethylene carbonate to the electrolyte can improve the performance of the SEI membrane (solid electrolyte membrane) and can prevent the electrolyte from further decomposing to at least a certain extent, thereby improving the performance of the electrolyte.
  • the electrolyte may further include a lithium salt, such as bis(fluorosulfonyl)imide lithium salt, lithium hexafluorophosphate, and the like.
  • a lithium salt such as bis(fluorosulfonyl)imide lithium salt, lithium hexafluorophosphate, and the like.
  • the electrolyte may include ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide lithium salt, and the above electrolyte may perform a good ion-conducting function in the intermediate layer.
  • S300 coating the intermediate layer precursor liquid on at least one side of the surface of the first substrate to form an intermediate layer precursor liquid coating layer, and performing heat treatment to obtain an isolation film.
  • the intermediate layer precursor solution may be coated on one surface of the first substrate. In other embodiments of the present application, the intermediate layer precursor solution may be coated on both surfaces of the first substrate.
  • the intermediate layer precursor liquid After the intermediate layer precursor liquid is coated on the surface of the first substrate, part of the intermediate layer precursor liquid will penetrate into the pores of the first substrate. During the heating process, the intermediate layer precursor liquid will undergo partial micro-crosslinking and curing, and the electrolyte will micro-gel to form an intermediate layer.
  • the temperature of the heating treatment can be 60°C-70°C.
  • the temperature of the heating treatment can be 60°C, 63°C, 65°C, 68°C, 70°C, etc.
  • the intermediate layer precursor liquid can undergo partial micro-cross-linking and curing, thereby obtaining an isolation film with a micro-cross-linking structure.
  • the heating treatment time can be 1h-20h.
  • the heating treatment time can be 1h, 3h, 5h, 8h, 10h, 12h, 15h, 20h, etc. Therefore, within the above time range, the intermediate layer precursor liquid can undergo partial micro-cross-linking and curing, and excessive cross-linking reaction is not easy to occur.
  • the method for preparing the aforementioned isolation film may further include: arranging a second substrate on the surface of the intermediate layer precursor liquid coating layer away from the first substrate.
  • the second substrate can cooperate with the first substrate to better coat and fix the intermediate layer precursor liquid coating layer, and after the heat treatment, a film material with a more firmly bonded overall structure can be obtained.
  • the intermediate layer precursor solution may further include at least one of an inorganic filler, an oligomer, a second monomer, and an initiator.
  • an inorganic filler can improve the thermal stability of the prepared isolation membrane; adding an oligomer can rapidly reduce the porosity of the prepared isolation membrane at a higher temperature, thereby improving the thermal stability of the isolation membrane; the second monomer can be cured at a lower temperature, and can be cured during the heating process, which is conducive to the formation of a micro-crosslinked structure; the initiator can induce partial micro-crosslinking and curing of the intermediate layer precursor solution during the heating process, thereby obtaining a micro-crosslinked and cured intermediate layer after the heating treatment.
  • the second monomer may include pentaerythritol triacrylate, etc.
  • the second monomer may be cross-linked and cured, which is conducive to obtaining an isolation film with a micro-cross-linked structure.
  • the isolation membrane prepared by the above method has a higher porosity at a lower temperature, which is conducive to the conduction of ions; at a higher temperature, the porosity of the isolation membrane decreases significantly, the pores are blocked, and it is difficult for ions to pass through, which can effectively alleviate
  • the problem of continuous temperature rise caused by the exchange of positive and negative ions at higher temperatures can be solved, thereby reducing the probability of thermal runaway of the battery; the above method is simple to operate and easy to implement, which is beneficial to improving the yield of the product and is convenient for large-scale production.
  • the present application proposes a battery.
  • the battery includes a positive electrode sheet, a negative electrode sheet, and a separator located between the positive electrode sheet and the negative electrode sheet, and the separator includes the aforementioned separator.
  • the battery has all the features and advantages of the aforementioned separator, which will not be repeated here.
  • the battery has good thermal stability and a low probability of thermal runaway.
  • FIG. 5 is a battery 5 of a square structure as an example.
  • the outer packaging of the battery 5 may include a shell 51 and a cover plate 53.
  • the shell 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate are enclosed to form a receiving cavity.
  • the shell 51 has an opening connected to the receiving cavity, and the cover plate 53 can be covered on the opening to close the receiving cavity.
  • the positive electrode sheet, the negative electrode sheet and the separator can be wound or laminated to form an electrode assembly 52.
  • the electrode assembly 52 is encapsulated in the accommodating cavity, and the electrolyte fills the internal space of the electrode assembly 52.
  • the number of electrode assemblies 52 contained in the battery 5 can be one or more, and those skilled in the art can select according to specific actual needs.
  • batteries can be assembled into battery modules, and the number of batteries contained in the battery module can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery module.
  • Figure 7 is a battery module 4 as an example. Referring to Figure 7, in the battery module 4, multiple batteries 5 can be arranged in sequence along the length direction of the battery module 4. Of course, they can also be arranged in any other way. The multiple batteries 5 can further be fixed by fasteners.
  • the battery module 4 can also include a housing with a accommodating space, and the multiple batteries 5 are accommodated in the accommodating space.
  • the above-mentioned battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be one or more, and the specific number can be selected by those skilled in the art according to the application and capacity of the battery pack.
  • Figures 8 and 9 are battery packs 1 as an example.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 arranged in the battery box.
  • the battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 to form a closed space for accommodating the battery module 4.
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the battery may be a lithium-ion battery
  • the positive electrode active material of the positive electrode plate may include one or more of lithium iron phosphate, nickel-cobalt-manganese ternary material, lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium vanadate, etc.
  • the negative electrode active material of the negative electrode plate may include one or more of graphite, silicon-based negative electrode material, mesophase carbon microbeads, hard carbon, soft carbon, and the like.
  • the positive electrode sheet and the negative electrode sheet may include a conductive agent and a binder, wherein the conductive agent in the positive electrode sheet and the conductive agent in the negative electrode sheet may each independently include one or more of carbon nanotubes, carbon black, carbon fiber, graphene, etc., and the binder in the positive electrode sheet and the binder in the negative electrode sheet may each independently include Including one or more of polyvinyl alcohol, polyurethane, polyacrylate, polyvinylidene fluoride, nitrile rubber, epoxy resin, vinyl acetate resin, chlorinated rubber and the like.
  • the present application provides an electrical device.
  • the electrical device includes the battery described above. Therefore, the electrical device has all the features and advantages of the battery described above, which will not be repeated here.
  • Batteries, battery modules or battery packs can be used as power sources for electrical devices, or as energy storage units for electrical devices.
  • Electrical devices may include mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto. Electrical devices may select batteries, battery modules or battery packs according to their usage requirements.
  • FIG10 is an example of an electric device.
  • the electric device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
  • a battery pack or a battery module can be used.
  • the power-consuming device may also be a mobile phone, a tablet computer, a laptop computer, etc.
  • a mobile phone a tablet computer, a laptop computer, etc.
  • Such a device is usually required to be light and thin, and a battery may be used as a power source.
  • a first substrate is provided, wherein the material of the first substrate is polyimide and the thickness of the first substrate is 8 microns; maleic anhydride monomer (first monomer), second monomer pentaerythritol triacrylate and initiator azobisisobutyronitrile are added to an electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide) is 3:2:1, wherein the mass ratio of the electrolyte, maleic anhydride monomer, pentaerythritol triacrylate and azobisisobutyronitrile is 70:20:10:0.2, and the mixture is stirred at room temperature for 6 hours to be evenly mixed to obtain an intermediate layer precursor solution; the intermediate layer precursor solution is coated on one side of the first substrate to form an intermediate layer precursor solution coating layer with a thickness of 3 microns, and a second substrate is attached to the surface of the intermediate layer precursor solution coating layer away from the first substrate,
  • the intermediate layer precursor solution During the heating process, some components in the intermediate layer precursor solution are micro-crosslinked and cured (mainly the curing of pentaerythritol triacrylate), and the electrolyte is micro-gelled.
  • the intermediate layer of the obtained isolation membrane has a micro-crosslinked structure, and the micro-gelled electrolyte can assume the ion conduction function.
  • the mass content of the first monomer is 10 wt %.
  • a first substrate is provided, wherein the material of the first substrate is polyimide and the thickness of the first substrate is 8 microns.
  • Maleic anhydride monomer (first monomer), inorganic filler SiO2 having carbon-carbon double bond functional groups on the surface and polythiophenyl phenoxy polymer (oligomer) are added to an electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide lithium salt is 3:2:1), wherein the mass ratio of the electrolyte, the maleic anhydride monomer, the inorganic filler SiO2 and the polythiophenyl phenoxy polymer is 70:15:15:1.5, and the mixture is stirred at room temperature for 6 hours and mixed evenly to obtain an intermediate layer precursor solution; the intermediate layer precursor solution is coated on one side of the first substrate to form an intermediate layer precursor solution coating layer with a thickness of 5 microns, a second substrate is attached to the surface of the intermediate layer
  • the mass content of the first monomer is 10 wt %
  • the mass content of the inorganic filler is 10 wt %
  • the mass content of the oligomer is 1 wt %.
  • a first substrate is provided, wherein the material of the first substrate is polyimide and the thickness of the first substrate is 8 microns; maleic anhydride monomer (first monomer), second monomer pentaerythritol triacrylate and initiator azobisisobutyronitrile are added to an electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide) is 3:2:1, wherein the mass ratio of the electrolyte, maleic anhydride monomer, pentaerythritol triacrylate and azobisisobutyronitrile is 80:10:10:0.2, and the mixture is stirred at room temperature for 6 hours to be evenly mixed to obtain an intermediate layer precursor solution; the intermediate layer precursor solution is coated on one side of the first substrate to form an intermediate layer precursor solution coating layer with a thickness of 3 microns, and a second substrate is attached to the surface of the intermediate layer precursor solution coating layer away from the first substrate,
  • the intermediate layer precursor solution During the heating process, some components in the intermediate layer precursor solution are micro-crosslinked and cured (mainly the curing of pentaerythritol triacrylate), and the electrolyte is micro-gelled.
  • the intermediate layer of the obtained isolation membrane has a micro-crosslinked structure, and the micro-gelled electrolyte can assume the ion conduction function.
  • the mass content of the first monomer is 5 wt %.
  • a first substrate is provided, wherein the material of the first substrate is polyimide and the thickness of the first substrate is 8 microns; maleic anhydride monomer (first monomer), second monomer pentaerythritol triacrylate and initiator azobisisobutyronitrile are added to an electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide) is 3:2:1, wherein the mass ratio of the electrolyte, maleic anhydride monomer, pentaerythritol triacrylate and azobisisobutyronitrile is 60:30:10:0.2, and the mixture is stirred at room temperature for 6 hours to be uniformly mixed to obtain an intermediate layer precursor solution; the intermediate layer precursor solution is coated on one side of the first substrate to form an intermediate layer precursor solution coating layer with a thickness of 3 microns, and a second substrate is bonded to the surface of the intermediate layer precursor solution coating layer away from the first
  • the intermediate layer precursor solution During the heating process, some components in the intermediate layer precursor solution are micro-crosslinked and cured (mainly the curing of pentaerythritol triacrylate), and the electrolyte is micro-gelled.
  • the intermediate layer of the obtained isolation membrane has a micro-crosslinked structure, and the micro-gelled electrolyte can assume the ion conduction function.
  • the mass content of the first monomer is 15 wt %.
  • a first substrate is provided, wherein the material of the first substrate is polyimide and the thickness of the first substrate is 8 microns; maleic anhydride monomer (first monomer), second monomer pentaerythritol triacrylate and initiator azobisisobutyronitrile are added to an electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate and bis(fluorosulfonyl)imide) is 3:2:1, wherein the mass ratio of the electrolyte, maleic anhydride monomer, pentaerythritol triacrylate and azobisisobutyronitrile is 50:40:10:0.2, and the mixture is stirred at room temperature for 6 hours and mixed evenly to obtain an intermediate layer precursor solution; the intermediate layer precursor solution is coated on one side surface of the first substrate to form an intermediate layer precursor solution coating layer with a thickness of 3 microns, and a second substrate is attached to the surface of the intermediate layer precursor solution coating layer away from the first substrate,
  • the intermediate layer precursor solution During the heating process, some components in the intermediate layer precursor solution are micro-crosslinked and cured (mainly the curing of pentaerythritol triacrylate), and the electrolyte is micro-gelled.
  • the intermediate layer of the obtained isolation membrane has a micro-crosslinked structure, and the micro-gelled electrolyte can assume the ion conduction function.
  • the mass content of the first monomer is 20 wt %.
  • Example 1 The difference from Example 1 is that the heating treatment temperature is 60° C. and the holding time is 20 h.
  • the other parameters and steps are the same as those in Example 1.
  • Example 1 The difference from Example 1 is that the maleic anhydride monomer is replaced by 2-chloromaleic anhydride monomer. In the isolation membrane, the mass content of 2-chloromaleic anhydride monomer is 10 wt%. The remaining parameters and steps are the same as those in Example 1.
  • Example 2 The difference from Example 2 is that the temperature of the heating treatment is 60° C.
  • the other parameters and steps are the same as those of Example 2.
  • Example 2 maleic anhydride monomer and inorganic filler SiO 2 having carbon-carbon double bond functional groups on the surface were added to the electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate, and bis(fluorosulfonyl)imide) was 3: 2 :1, and no oligomer was added, wherein the mass ratio of the electrolyte, maleic anhydride monomer (first monomer) and inorganic filler SiO 2 was 62.5:15:22.5. In the isolation film, the mass content of the first monomer was 10wt%, and the mass content of the inorganic filler was 15wt%. The remaining parameters and steps are the same as those in Example 2.
  • Example 2 maleic anhydride monomer and polythiophene phenoxy polymer were added to the electrolyte (the mass ratio of ethyl methyl carbonate, fluoroethylene carbonate, and bis(fluorosulfonyl)imide lithium salt was 3:2:1), and no inorganic filler was added, wherein the mass ratio of the electrolyte, maleic anhydride monomer (first monomer) and polythiophene phenoxy polymer (oligomer) was 85:15:1.5, and the thickness of the intermediate layer precursor coating layer was 3 microns.
  • the mass content of the first monomer was 10wt%
  • the mass content of the oligomer was 1wt%.
  • the remaining parameters and steps were the same as those in Example 2.
  • the mass ratio of the electrolyte, maleic anhydride monomer (first monomer), inorganic filler SiO2 and polythiophene phenoxy polymer (oligomer) is 55:15:30:1.5, and the thickness of the intermediate layer precursor coating layer is 6 microns.
  • the mass content of the first monomer is 10wt%
  • the mass content of the inorganic filler is 20wt%
  • the mass content of the oligomer is 1wt%.
  • the mass ratio of the electrolyte, maleic anhydride monomer (first monomer), inorganic filler SiO2 and polythiophene phenoxy polymer (oligomer) is 83.5:15:1.5:1.5, and the thickness of the intermediate layer precursor coating layer is 4 microns.
  • the mass content of the first monomer is 10wt%
  • the mass content of the inorganic filler is 1wt%
  • the mass content of the oligomer is 1wt%.
  • the remaining parameters and steps are the same as those in Example 2.
  • Example 2 The difference from Example 2 is that the mass ratio of the electrolyte, maleic anhydride monomer (first monomer), inorganic filler SiO2 and polythiophene phenoxy polymer (oligomer) is 70:15:15:15.
  • the mass content of the first monomer is 10wt%
  • the mass content of the inorganic filler is 10wt%
  • the mass content of the oligomer is 10wt%.
  • the remaining parameters and steps are the same as those in Example 2.
  • Example 2 The difference from Example 2 is that the mass ratio of the electrolyte, maleic anhydride monomer (first monomer), inorganic filler SiO2 and polythiophene phenoxy polymer (oligomer) is 70:15:15:0.15.
  • the mass content of the first monomer is 10wt%
  • the mass content of the inorganic filler is 10wt%
  • the mass content of the oligomer is 0.1wt%.
  • the remaining parameters and steps are the same as those in Example 2.
  • Example 2 Different from Example 1, maleic anhydride was not added to the electrolyte, and the mass ratio of the electrolyte, pentaerythritol triacrylate, and azobisisobutyronitrile was 90:10:0.2. In the isolation film, the mass content of the first monomer was 0. The remaining parameters and steps were the same as those in Example 1.
  • the isolation film is formed from a polyimide substrate and has a thickness of 13 microns.
  • Preparation of positive electrode sheet Add positive electrode active material NCM811 (in the positive electrode active material, the molar ratio of nickel, cobalt and manganese is 8:1:1), binder polyvinylidene fluoride (PVDF), and conductive agent (acetylene black) to a certain amount of N-methylpyrrolidone (NMP), and the mass ratio of positive electrode active material: binder: conductive agent is 9:0.5:0.5, stir in a drying room to make a uniform positive electrode slurry, control the viscosity to 3000mPa ⁇ S-10000mPa ⁇ S, coat the above positive electrode slurry on aluminum foil, and obtain the positive electrode sheet after drying.
  • the positive electrode sheet is compacted, and the compaction density of the positive electrode sheet is 3.4g/ cm3 .
  • Preparation of negative electrode sheet Add negative electrode active materials graphite, sodium carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR), and conductive agent (carbon fiber) into a certain amount of deionized water, with the mass ratio of graphite: sodium carboxymethyl cellulose: styrene butadiene rubber: conductive agent being 9:0.3:0.2:0.5, stir to make a uniform negative electrode slurry, control the viscosity to be 3000mPa ⁇ S-10000mPa ⁇ S, coat the above negative electrode slurry on copper foil, and obtain the negative electrode sheet after drying.
  • the negative electrode sheet is compacted, and the compaction density of the negative electrode sheet is 1.5g/ cm3 .
  • the prepared positive electrode sheet, negative electrode sheet and isolation film are made into corresponding battery cells according to a Z-shaped stacking structure, and the battery cells are vacuum-dried at 90°C for 12 hours, followed by ultrasonic welding of the positive and negative electrode tabs, wherein the positive electrode adopts an aluminum tab and the negative electrode adopts a nickel tab, and the positive and negative electrode tabs are located on the same side of the battery cell.
  • the battery cell after the tab welding is loaded into an aluminum-plastic film of a suitable size for top-side sealing packaging, and the top-side sealing temperature is 145°C, and liquid is injected (the electrolyte of the battery consists of ethyl methyl carbonate, fluoroethylene carbonate and lithium bis(fluorosulfonyl)imide salt, and the mass ratio of ethyl methyl carbonate:fluoroethylene carbonate: lithium bis(fluorosulfonyl)imide salt is 3:2:1), allowed to stand, formed, aged, exhausted, double-sealed, and capacity tested to obtain the prepared soft-pack laminated battery.
  • the mass content of the first monomer, the inorganic filler, and the oligomer in the isolation membrane of each embodiment and comparative example, the porosity of the isolation membrane of each embodiment and comparative example at different temperatures, and the thermal runaway data of the battery were tested, and the test results were recorded in Table 1.
  • the initial total mass of the isolation film is recorded as A.
  • Test for the mass content of the electrolyte in the isolation membrane Using the vacuum method, the isolation membrane is kept at 40°C and a vacuum degree of -0.1Mpa for 20 hours. The remaining mass is recorded as B, and the ratio of (A-B)/A is recorded as the mass content of the electrolyte.
  • Test method for the mass content of inorganic filler in isolation membrane the mass of the isolation membrane after combustion (under air atmosphere, temperature not less than 800 degrees Celsius) is recorded as C, and the ratio of C/A is recorded as the mass content of inorganic filler.
  • the mass content test method of the first monomer and oligomer is as follows: the middle layer on the isolation film is scraped off, and then the mass of the scraped material is determined by high performance liquid chromatography, which are recorded as D and E respectively. The ratio of D/A to E/A is recorded as the mass content of the first monomer and the mass content of the oligomer respectively.
  • the intermediate layer on the isolation film is scraped off, and the remaining is the isolation film substrate, and its mass is recorded as F.
  • the mass content of the second monomer the ratio of (A-B-C-D-E-F)/A is recorded as the mass content of the second monomer.
  • the specific test method for the porosity of the isolation membrane can refer to GB/T 21650.2-2008 "Determination of pore size distribution and porosity of solid materials by mercury intrusion and gas adsorption method Part 2: Analysis of mesopores and macropores by gas adsorption method".
  • Hot box test Place the battery in a high temperature box, heat it up at a rate of 1°C/min, start at 120°C, and keep it warm for 30 minutes every 5°C until the battery fails (failure criteria are fire or explosion). If the battery does not fail at temperature A, it is considered to have passed the A temperature hot box test, and the battery hot box temperature is greater than temperature A.
  • the middle layer of the isolation membrane has the first monomer, and at a lower temperature, the isolation membrane has a higher porosity.
  • the first monomer in the isolation membrane polymerizes, thereby blocking the pores of the isolation membrane and significantly reducing the porosity of the isolation membrane, thereby inhibiting the conduction of ions at high temperatures and alleviating the positive and negative ions at higher temperatures.
  • the porosity of the isolation membrane at the first temperature and the second temperature is slightly different. At the higher second temperature, the porosity of the isolation membrane is higher, and the hot box temperature of the battery thermal runaway test is lower.
  • Example 1 By comparing Example 1 with Examples 3-5, it can be seen that within a certain range, the higher the content of the first monomer in the isolation membrane, the lower the porosity of the isolation membrane at a higher temperature, and the higher the hot box temperature of the battery thermal runaway test.
  • Example 14 Compared with Example 2, Example 13 and Example 14, the higher the content of oligomers in the isolation membrane, the higher the porosity at the first temperature, the lower the porosity at the second temperature, and the higher the hot box temperature of the battery thermal runaway test.
  • Example 11 Compared with Example 11 and Example 12, the higher the content of inorganic filler in the isolation membrane, the higher the porosity at the first temperature, the lower the porosity at the second temperature, and the higher the hot box temperature of the battery thermal runaway test.
  • Example 6 Compared with Example 1 and Example 6, the heating treatment temperature in Example 6 is lower, and the porosity of the isolation film at the first temperature is higher. Compared with Example 2 and Example 8, the heating temperature in Example 8 is lower, and the porosity of the isolation film at the first temperature is higher.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Inorganic Chemistry (AREA)
  • Cell Separators (AREA)
  • Laminated Bodies (AREA)

Abstract

本申请公开了隔离膜及其制备方法、电池和用电装置。所述隔离膜包括：第一基材，以及位于所述第一基材至少一侧表面的中间层，所述隔离膜在第一温度下的孔隙率为a，所述隔离膜在第二温度下的孔隙率为b，所述第一温度为-20℃～100℃，40％≤a≤70％，所述第二温度不低于120℃，b≤2％。

Description

隔离膜及其制备方法、电池和用电装置
相关申请的交叉引用
本申请要求于2023年4月27日提交的申请号为202310473685.0的中国专利申请的优先权权益，并将其全部引入本文。
技术领域
本申请涉及电池技术领域，具体地，涉及隔离膜及其制备方法、电池和用电装置。
背景技术
在电池结构中，隔离膜是关键的内层结构之一，隔离膜起到隔离正极和负极的作用，防止正极和负极接触短路，在电池使用过程中，隔离膜还需要起到传导离子的作用。目前的隔离膜在较高温度下的稳定性较差，导致电池存在热失控风险。
因此，目前的隔离膜及其制备方法、电池和用电装置仍有待改进。
发明内容
本申请旨在至少一定程度上缓解或解决上述提及问题中的至少一个。
在本申请的一方面，本申请提出了一种隔离膜。在本申请的一些实施例中，所述隔离膜包括：第一基材，以及位于所述第一基材至少一侧的中间层，所述隔离膜在第一温度下的孔隙率为a，所述隔离膜在第二温度下的孔隙率为b，所述第一温度为-20℃～100℃，40％≤a≤70％，所述第二温度不低于120℃，b≤2％。由此，隔离膜在较低温度下具有较高的孔隙率，有利于离子通过；在较高温度下，隔离膜的孔隙率显著降低，隔离膜孔道阻塞，可以至少在一定程度上隔绝离子传导，从而缓解较高温度下正负离子交换而产生的持续升温，进而降低电池热失控的概率。
在本申请的一些实施例中，第三温度为-20℃～120℃，在所述第三温度下，所述中间层包括第一单体，所述第一单体满足以下条件的至少一种：所述第一单体的分子中含有环状结构，所述环状结构的原子数小于等于7，所述环状结构上具有第一官能团；所述第一单体的分子量不低于90；所述第一单体的聚合温度不低于120℃。由此，第一单体在较低温度下较难发生聚合反应，可以使隔离膜保持较高的孔隙率，有利于离子的传导。
在本申请的一些实施例中，基于所述隔离膜的总质量，所述第一单体的质量含量为0.1wt％-20wt％。由此，隔离膜中含有适量的第一单体，在较高温度下第一单体发生聚合，可以显著降低隔离膜的孔隙率，从而提高隔离膜的热稳定性。
在本申请的一些实施例中，所述中间层进一步包括无机填料，所述无机填料满足以下条件中的至少一种：所述无机填料包括惰性无机填料，所述惰性无机填料包括二氧化硅、二氧化钛、氧化锌、氧化锆、氧化镁、氧化钡、三氧化二铝、钛酸钡和氢氧化镁中的至少一种；所述无机填料包括活性无机填料，所述活性无机填料包括石榴石型固态电解质、钙钛矿型固态电解质、反钙钛矿型固态电解质、钠超离子导体型固态电解质和锂磷氮氧型固态电解质中的至少一种；所述无机填料的表面具有第二官能团，所述第二官能团包括氨基、环氧基、碳碳双键、醛基、羟基、糠酯基、酰亚胺基和异腈酸酯基中的至少一种。由此，无机填料可以降低隔离膜的热收缩率、提高隔离膜的抗刺穿能力，从而有利于进一步提高隔离膜的性能。
在本申请的一些实施例中，基于所述隔离膜的总质量，所述无机填料的质量含量为1wt％-20wt％。由此，上述含量的无机填料可以显著提高隔离膜的热收缩率和抗刺穿能力，并且，不会对离子的传导造成明显的不利影响。
在本申请的一些实施例中，所述中间层进一步包括寡聚物，所述寡聚物含有稳定自由基，所述寡聚物满足以下条件中的至少之一：所述寡聚物是由2-20个重复单元所组成的聚合物；所述寡聚物的分子量为200-10000；所述稳定自由基包括三苯甲基、硝基和氮氧化物自由基中的至少一种。由此，寡聚物含有的稳定自由基可以在较高温度下与第一单体反应，使第一单体更快聚合，从而降低较高温度下隔离膜的孔隙率。
在本申请的一些实施例中，所述氮氧化物自由基包括4-羟基-2,2,6,6-四甲基哌啶-N-氧单体、聚-2,2,6,6-四甲基哌啶-4-甲基丙烯酸酯-1-氮氧自由基和2,2,6,6-四甲基-哌啶氮氧自由基中的至少一种。
在本申请的一些实施例中，所述寡聚物包括聚噻吩基苯氧基聚合物、芳基甲基自由基聚合物、氮氧自由基官能化聚丙烯胺树枝状聚合物、共轭自由基聚合物、梳状氮氧自由基聚合物、聚乙烯胺负载的氮氧自由基聚合物和聚乙烯胺负载的硝基自由基聚合物中的至少一种。
在本申请的一些实施例中，基于所述隔离膜的总质量，所述寡聚物的质量含量为0.1wt％-10％wt。由此，在较高温度下，寡聚物可以使第一单体快速聚合，快速降低隔离膜的孔隙率。
在本申请的一些实施例中，所述隔离膜进一步包括第二基材，所述第二基材位于所述中间层远离所述第一基材的一侧。由此，第二基材可以与第一基材配合，将中间层包覆起来，形成结构稳定的膜层。
在本申请的一些实施例中，所述第一基材和所述第二基材各自独立地包括聚酰胺、聚酰胺酰亚胺、聚酮、聚砜、聚苯硫醚、聚苯醚、聚偏二氟乙烯、聚四氟乙烯、聚氯乙烯、 聚烯烃、全氟烷氧基烷烃、聚酯、液晶聚合物、聚甲醛、丙烯腈苯乙烯丙烯酸酯、苯乙烯丙烯腈、丙烯腈丁二烯苯乙烯、聚苯并咪唑、聚对苯撑共聚物、聚丙烯腈、聚乙烯亚胺、乙烯四氟乙烯、聚氯三氟乙烯、芳纶、聚醚酰亚胺、聚对苯撑苯并二噁唑和纤维素中的至少一种。由此，第一基材和第二基材均具有良好的电子绝缘性能，可以较好的隔离正极和负极，具有良好的离子传导性能，可以在充放电过程中传导离子；并且，具有一定的机械强度，可以在一定程度上抵抗枝晶刺穿。
在本申请的另一方面，本申请提出了一种制备前面所述的隔离膜的方法。在本申请的一些实施例中，制备前面所述的隔离膜的方法包括：提供第一基材；制备中间层前驱液，所述中间层前驱液包括电解液和第一单体；将所述中间层前驱液涂覆在所述第一基材的至少一侧表面，形成中间层前驱液涂覆层，加热处理，得到隔离膜。由此，制备得到的隔离膜具有前面所述的隔离膜所具有的全部特征以及优点，在此不再赘述；该方法操作简便，易实现，有利于提高产品良率。
在本申请的一些实施例中，在所述加热处理之前，制备前面所述的隔离膜的方法进一步包括：在所述中间层前驱液涂覆层远离所述第一基材的一侧设置第二基材。由此，第二基材可以与第一基材配合，起到固定中间层前驱液涂覆层的作用。
在本申请的一些实施例中，所述中间层前驱液进一步包括无机填料、寡聚物、第二单体和引发剂中的至少一种。由此，无机填料具有较好的热稳定性，有利于提高隔离膜的热稳定性；寡聚物可以在较高温度下与第一单体反应，快速降低隔离膜的孔隙率；第二单体可以在较低温度下固化；引发剂可以引发中间层前驱液中部分组分的微交联固化，使中间层前驱液涂覆层快速形成中间层。
在本申请的一些实施例中，制备前面所述的隔离膜的方法满足以下条件中的至少之一：所述电解液包括碳酸甲乙酯、氟代碳酸乙烯酯和双氟磺酰亚胺锂盐；所述第二单体包括季戊四醇三丙烯酸酯；所述加热处理的温度为60℃-70℃；所述加热处理的时间为1h-20h。由此，电解液可以起到传导锂离子的作用；加热处理的温度或时间设置在上述范围内，可以使中间层前驱液中的部分组分发生微交联固化，得到性能优异的隔离膜。
在本申请的又一方面，本申请提出了一种电池。在本申请的一些实施例中，所述电池包括正极极片、负极极片，以及位于所述正极极片和所述负极极片之间的隔离件，所述隔离件包括前面所述的隔离膜。由此，该电池具有前面所述的隔离膜所具有的全部特征以及优点，在此不再赘述。总的来说，该电池具有良好的热稳定性，热失控的概率较低。
在本申请的又一方面，本申请提出了一种用电装置。在本申请的一些实施例中，所述用电装置包括前面所述的电池。由此，该用电装置具有前面所述的电池所具有的全部特征以及优点，在此不再赘述。
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显示了根据本申请一个实施例的隔离膜的结构示意图；
图2显示了根据本申请另一个实施例的隔离膜的结构示意图；
图3显示了根据本申请又一个实施例的隔离膜的结构示意图；
图4显示了根据本申请又一个实施例的隔离膜的结构示意图；
图5显示了根据本申请一个实施例的电池的结构示意图；
图6显示了图5中电池的爆炸图；
图7显示了根据本申请一个实施例的电池模块的结构示意图；
图8显示了根据本申请一个实施例的电池包的结构示意图；
图9显示了图8中电池包的爆炸图；
图10显示了根据本申请一个实施例的电池用作电源的用电装置的结构示意图。
附图标记说明：
100：隔离膜；110：第一基材；120：中间层；130：第二基材；1：电池包；2：上箱
体；3：下箱体；4：电池模块；5：电池；51：壳体；52：电极组件；53：盖板。
具体实施方式
下面详细描述本申请的实施例，所述实施例的示例在附图中示出，其中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功能的元件。下面通过参考附图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。
在本文中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其它实施例相结合。
为了简明，本文仅具体地公开了一些数值范围。然而，任意下限可以与任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。
除非另有定义，本文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；本文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。
在电池结构中，隔离膜起到隔离正负极以及传导离子的作用，在较高的温度下，隔离膜如果继续传导离子，则可能会由于高温下正负离子交换产生持续升温的问题，导致电池可能出现热失控的风险。通过在隔离膜基材的一侧设置中间层，使得隔离膜在较低的温度下具有较高的孔隙率，充放电过程中可以较好的传导离子，另外，使得隔离膜在较高的温度下孔隙率较低，可以阻碍高温下离子的传导，从而缓解高温下正负离子交换产生的持续升温问题，进而降低电池热失控的风险。
通常情况下，隔离膜可以应用于液态电解质电池或半固态电解质电池中，例如，隔离膜可以应用于液态电解质锂离子电池、半固态电解质锂离子电池等中。
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装置或者使用电池作为储能元件的各种储能系统。用电装置可以为但不限于手机、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。
在本申请的一方面，本申请提出了一种隔离膜。在本申请的一些实施例中，参考图1至图4，隔离膜100可以包括第一基材110以及位于第一基材110至少一侧的中间层120。其中，隔离膜100在第一温度下的孔隙率为a，隔离膜100在第二温度下的孔隙率为b，第一温度可以为-20℃～100℃，40％≤a≤70％，例如，第一温度可以为-20℃、-10℃、-5℃、0℃、10℃、30℃、50℃、80℃、100℃等，a可以为40％、45％、50％、55％、60％、65％、70％等，第二温度可以不低于120℃，b≤2％，例如，第二温度可以为120℃、130℃、150℃、170℃等，b可以为0.2％、0.5％、1％、1.5％、1.8％、2％等。
本文中，术语“孔隙率”是指隔离膜中孔隙的总体积占隔离膜在自然状态下的总体积的百分比。在较低的温度下，隔离膜具有较大的孔隙率，隔离膜在充放电过程中可以起到较好的离子传导作用；在较高的温度下，中间层中的部分组分会发生聚合反应，使隔离膜的孔隙率降低，电池的内阻增大，可以至少在一定程度上隔绝离子传导，从而有效缓解甚至解决较高温度下正负离子交换产生的持续升温问题，进而降低电池热失控的概率，有利于提高电池的热稳定性。
在本申请的一些实施例中，参考图1和图3，隔离膜100中，第一基材110的一侧表面可以设置有中间层120。在本申请的另一些实施例中，参考图2和图4，隔离膜100中，第一基材110的两个表面可以均设置有中间层120。
在本申请的一些实施例中，参考图3和图4，隔离膜100可以进一步包括第二基材130，第二基材130位于中间层120远离第一基材110的一侧。由此，第二基材可以与第一基材配合，将中间层牢固包覆起来，从而有利于提高隔离膜的结构稳定性。
在本申请的一些实施例中，参考图3，隔离膜100包括依次层叠设置的第一基材110、中间层120和第二基材130。在本申请的另一些实施例中，参考图4，第一基材110的两个表面均设置有中间层120，在每个中间层120远离第一基材110的表面上均设置有第二基材130。
在本申请的一些实施例中，第一基材110和第二基材130可以各自独立地包括聚酰胺(PA)、聚酰胺酰亚胺(PAI)、聚酮、聚砜(PSU)、聚苯硫醚(PPS)、聚苯醚(PPE)、聚偏二氟乙烯(PVDF)、聚四氟乙烯(PTFE)、聚氯乙烯(PVC)、聚烯烃、全氟烷氧基烷烃(PFA)、聚酯、液晶聚合物(LCP)、聚甲醛(POM)、丙烯腈苯乙烯丙烯酸酯(ASA)、苯乙烯丙烯腈(SAN)、丙烯腈丁二烯苯乙烯(ABS)、聚苯并咪唑(PBI)、聚对苯撑共聚物(PPP)、聚丙烯腈、聚乙烯亚胺、乙烯四氟乙烯(ETFE)、聚氯三氟乙烯(PCTFE)、芳纶、聚醚酰亚胺(PEI)、聚对苯撑苯并二噁唑和纤维素等中的至少一种。在本申请的一些实施例中，第一基材110和第二基材130可以各自独立地由上述材料中的一种构成；在本申请的一些实施例中，第一基材110和第二基材130可以各自独立地由上述材料中的两种或更多种构成。上述材料作为基材，具有一定的强度，可以为中间层提供较好的支撑作用；上述材料均具有良好的电子绝缘性能以及良好的离子传导性能，可以起到隔绝正极和负极的作用以及传导离子的作用。
需要说明的是，聚对苯撑共聚物可以包括聚对苯撑乙炔类共聚物、聚对苯撑乙烯类共聚物等中的至少之一。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括聚酮，例如，聚醚酮(PEK)、聚醚醚酮(PEEK)、聚醚酮醚酮酮(PEKEKK)等。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括聚酰胺，例如，聚酰胺46(PA46)、聚酰胺66(PA66)、聚酰胺12(PA12)、聚酰胺11(PA11)、聚酰胺6(PA6)、聚酰胺6.6(PA6.6)、聚酰胺6.6/6(PA6.6/6)、无定形聚酰胺(PA6-3-T)、聚邻苯二甲酰胺(PPA)等。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括聚砜，例如，聚苯砜(PPSU)、聚醚砜(PES)等。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括聚酯，例如，聚对苯二甲酸乙二醇酯(PET)、聚碳酸酯(PC)、聚对苯二甲酸丁二醇酯(PBT)、聚甲基丙烯酸甲酯(PMMA)等。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括聚烯烃，例如，聚丙烯(PP)、聚乙烯(PE)、高密度聚乙烯(HDPE)、聚甲基戊烯(PMP)等。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括芳纶，例如，噻吩基芳纶、吡咯基芳纶、呋喃基芳纶等。
在本申请的一些实施例中，第一基材和第二基材可以各自独立地包括聚酰亚胺、聚丙烯、芳纶、噻吩基芳纶、吡咯基芳纶、呋喃基芳纶、吡啶基聚酰胺、聚酰胺酰亚胺、聚醚酰亚胺、聚砜、聚酮、聚对苯撑苯并二噁唑和纤维素中的至少一种，上述材料具有较好的耐高温收缩性能，在较高温度下收缩率较小，可以降低较高温度下正极和负极短路的风险。
在本申请的一些实施例中，中间层可以包括第一单体。
“单体”是指能够与同种或他种分子聚合的小分子。
在本申请的一些实施例中，第一单体的分子中可以含有环状结构，环状结构的原子数小于等于7，环状结构上具有第一官能团，由此，第一单体具有较大的位阻，第一单体反应活性较低，在较低温度下不易发生聚合反应，不易阻塞隔离膜的孔隙。
根据本申请的一些实施例，第一官能团可以包括但不限于碳氧双键、烃基官能团(例如，甲基、乙基、丙基、异丙基、丁基、异丁基、乙烯基、丙烯基等)、羧基、醚键、羰基等。
根据本申请的一些具体实施例，第一单体可以包括马来酸酐，马来酸酐的分子中含有环状结构，马来酸酐中环状结构的原子数是5，环状结构上具有第一官能团碳氧双键，该单体具有较大的位阻，反应活性较低，在较低温度下不易发生聚合反应。
需要说明的是，环状结构上的第一官能团不包括仅由构成环的原子形成的官能团，例如，马来酸酐中的碳碳双键、碳氧单键不属于马来酸酐环状结构上的第一官能团。
本文中，“位阻”指的是分子内部基团在空间排布造成的相互排斥作用。前述单体具有较大的位阻，对该单体的反应活性影响较大。
在本申请的一些实施例中，第一单体分子的环状结构中可以含有氮原子、氧原子等杂原子中的至少一种。
在本申请的一些实施例中，第一单体的分子量不低于90，由此，第一单体具有较大的分子量，第一单体混合物较为粘稠，不易聚合。
在本申请的一些实施例中，第一单体的聚合温度不低于120℃，由此，第一单体在较低温度下不易发生聚合反应，有利于离子的传导。
在本申请的一些实施例中，基于隔离膜的总质量，第一单体的质量含量可以为0.1wt％-20wt％，例如，第一单体的质量含量可以为0.1wt％、0.5wt％、1wt％、5wt％、10wt％、15wt％、20wt％等，由此，隔离膜中含有适量的第一单体，第一单体在较低温度下不易阻塞隔离膜的孔隙，隔离膜在较低温度下具有较好的离子传导性能；在较高温度下第一单体会发生聚合反应，阻塞孔隙，使隔离膜的孔隙率下降，隔绝离子传导，从而缓解高温下正负离子交换而产生的持续升温问题，降低电池热失控的概率。
在本申请的一些实施例中，中间层可以进一步包括无机填料。无机填料具有较好的强度，有利于提高隔离膜的抗刺穿能力；无机填料具有较好的热稳定性，有利于降低隔离膜的热收缩率，从而提高隔离膜的热稳定性。
在本申请的一些实施例中，无机填料可以包括惰性无机填料和/或活性无机填料，其中，惰性无机填料包括二氧化硅、二氧化钛、氧化锌、氧化锆、氧化镁、氧化钡、三氧化二铝、钛酸钡和氢氧化镁中的至少一种；活性无机填料包括石榴石型固态电解质、钙钛矿型固态电解质、反钙钛矿型固态电解质、钠超离子导体(NASICON)型固态电解质和锂磷氮氧(LiPON)型固态电解质中的至少一种。上述无机填料可以具有较好的热稳定性，可以至少在一定程度上提高隔离膜的热稳定性，并且，上述无机填料具有较高的强度，可以提高隔离膜的抗刺穿能力；上述活性无机填料还可以促进充放电过程中的离子传导。
在本申请的一些实施例中，无机填料的表面具有第二官能团，无机填料表面的第二官能团可以包括氨基、环氧基、碳碳双键、醛基、羟基、糠酯基、酰亚胺基和异腈酸酯基中的至少一种。由此，无机填料表面的上述第二官能团可以在较高温度下发生自聚合反应或者与第一单体反应，从而阻塞隔离膜中的孔隙，降低较高温度下隔离膜的孔隙率，从而降低正负离子的传导，进而缓解高温下正负离子交换而产生的持续升温问题，降低电池热失控的概率。
在本申请的一些实施例中，基于隔离膜的总质量，无机填料的质量含量可以为1wt％-20wt％，例如，无机填料的质量含量可以为1wt％、5wt％、10wt％、15wt％、20wt％等，上述含量的无机填料可以至少在一定程度上提高隔离膜的热稳定性和抗刺穿能力。
在本申请的一些实施例中，中间层进一步包括寡聚物，寡聚物含有稳定自由基。由此，寡聚物的稳定自由基可以在较高温度下与第一单体反应，使第一单体更快聚合，阻塞隔离膜的孔隙，从而隔绝离子的传导，缓解较高温度下正负离子交换产生的持续升温问题。
在本申请的一些实施例中，寡聚物是由2-20个重复单元所组成的聚合物，由此，寡聚物在较低的温度下不易阻塞孔隙，对较低温度下离子的传导没有明显的不良影响。
在本申请的一些实施例中，寡聚物的分子量为200-10000，由此，寡聚物的分子量较低，在较低温度下，寡聚物不易阻塞孔隙。
在本申请的一些实施例中，稳定自由基可以包括三苯甲基、硝基和氮氧化物自由基等中的至少一种，上述稳定自由基在较高温度下可以与第一单体反应，使第一单体更快聚合，从而快速阻塞隔离膜的孔隙。
在本申请的一些实施例中，氮氧化物自由基可以包括4-羟基-2,2,6,6-四甲基哌啶-N-氧单体、聚-2,2,6,6-四甲基哌啶-4-甲基丙烯酸酯-1-氮氧自由基和2,2,6,6-四甲基-哌啶氮氧自由基中的至少一种，由此，在较高温度下，上述自由基可以促进第一单体更快聚合，阻塞孔隙。
在本申请的一些实施例中，寡聚物可以包括聚噻吩基苯氧基聚合物、芳基甲基自由基聚合物、氮氧自由基官能化聚丙烯胺树枝状聚合物、共轭自由基聚合物、梳状氮氧自由基聚合物、聚乙烯胺负载的氮氧自由基聚合物和聚乙烯胺负载的硝基自由基聚合物中的至少一种。在较高温度下，上述寡聚物均可以与第一单体反应，促进第一单体快速聚合，从而快速降低隔离膜的孔隙率，隔绝离子的传导。
在本申请的一些实施例中，基于隔离膜的总质量，寡聚物的质量含量可以为0.1wt％-10％wt，例如，寡聚物的质量含量可以为0.1wt％、0.5wt％、1wt％、5wt％、10％wt等，由此，隔离膜中含有适量的寡聚物，可以在较高温度下促进第一单体的聚合，快速阻塞孔隙，减少离子的传导；在较低温度下，上述含量的寡聚物对离子的传导没有明显不良影响。
在本申请的另一方面，本申请提出了一种制备前面所述的隔离膜的方法。在本申请的一些实施例中，制备前面所述的隔离膜的方法可以包括以下步骤：
S100：提供第一基材。
关于第一基材的具体材料，已在前面进行了详细说明，在此不再赘述。
S200：制备中间层前驱液。
在本申请的一些实施例中，制备中间层前驱液，其中，中间层前驱液可以包括电解液和第一单体。
在本申请的一些实施例中，电解液可以包括碳酸酯，例如，碳酸乙酯(EC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸丙烯酯(PC)、碳酸甲乙酯(EMC)等，上述电解液可以在中间层中承担离子传导功能。
在本申请的一些实施例中，电解液还可以包括氟代碳酸乙烯酯，电解液中添加氟代碳酸乙烯酯，可以提高SEI膜(固态电解质膜)的性能，可以至少在一定程度上阻止电解液进一步分解，从而提高电解液的性能。
在本申请的一些实施例中，电解液还可以包括锂盐，例如双氟磺酰亚胺锂盐、六氟磷锂等。
在本申请的一些具体实施例中，电解液可以包括碳酸甲乙酯、氟代碳酸乙烯酯和双氟磺酰亚胺锂盐，上述电解液可以在中间层中起到良好的传导离子的功能。
关于第一单体的分子结构、分子量、聚合温度等特征，均已在前面进行了详细说明，在此不再赘述。
S300：将中间层前驱液涂覆在第一基材的至少一侧表面，形成中间层前驱液涂覆层，加热处理，得到隔离膜。
在本申请的一些实施例中，中间层前驱液可以涂覆在第一基材的一侧表面。在本申请的另一些实施例中，中间层前驱液可以涂覆在第一基材的两个表面。
将中间层前驱液涂覆在第一基材的表面后，部分中间层前驱液会渗入第一基材的孔隙中，加热处理过程中，中间层前驱液会发生部分微交联固化，电解液微凝胶化，形成中间层。
在本申请的一些实施例中，加热处理的温度可以为60℃-70℃，例如，加热处理的温度可以为60℃、63℃、65℃、68℃、70℃等，在上述温度下，中间层前驱液可以发生部分微交联固化，从而得到具有微交联结构的隔离膜。
在本申请的一些实施例中，加热处理的时间可以为1h-20h，例如，加热处理的时间可以为1h、3h、5h、8h、10h、12h、15h、20h等，由此，在上述时间范围内，中间层前驱液可以发生部分微交联固化，不易发生过量的交联反应。
在本申请的一些实施例中，在加热处理之前，制备前面所述的隔离膜的方法可以进一步包括：在中间层前驱液涂覆层远离第一基材的一侧表面设置第二基材。由此，第二基材可以与第一基材配合，对中间层前驱液涂覆层进行更好的包覆和固定，在加热处理后可以得到整体结合更为牢固的膜材。
在本申请的一些实施例中，中间层前驱液可以进一步包括无机填料、寡聚物、第二单体和引发剂中的至少一种。添加无机填料可以提高制备得到的隔离膜的热稳定性；添加寡聚物可以使得制备得到的隔离膜在较高温度下的孔隙率快速降低，从而提高隔离膜的热稳定性；第二单体可以在较低温度下固化，在加热处理过程中，即可固化，有利于形成微交联结构；引发剂可以在加热处理过程中引发中间层前驱液发生部分微交联固化，从而使得加热处理后得到微交联固化的中间层。
关于无机填料、寡聚物的具体材料，均已在前面进行了详细说明，在此不再赘述。
在本申请的一些实施例中，第二单体可以包括季戊四醇三丙烯酸酯等，在加热处理过程中，第二单体可以发生交联固化，有利于得到微交联结构的隔离膜。
利用上述方法制备得到的隔离膜，在较低温度下，孔隙率较高，有利于离子的传导；在较高温度下，隔离膜的孔隙率显著下降，孔隙阻塞，离子较难通过，从而可以有效缓解 较高温度下正负离子交换而产生的持续升温问题，进而降低电池热失控的概率；上述方法操作简便，易实现，有利于提高产品的良率，并且，便于大规模生产。
在本申请的又一方面，本申请提出了一种电池。在本申请的一些实施例中，该电池包括正极极片、负极极片以及位于正极极片和负极极片之间的隔离件，所述隔离件包括前面所述的隔离膜。由此，该电池具有前面所述的隔离膜所具有的全部特征以及优点，在此不再赘述。总的来说，该电池具有良好的热稳定性，热失控的概率较低。
作为示例，本申请对电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。例如，图5是作为一个示例的方形结构的电池5。具体地，参照图6，电池5的外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53能够盖设于开口，以封闭容纳腔。
作为示例，正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于容纳腔内，电解质填充电极组件52的内部空间。电池5所含电极组件52的数量可以为一个或多个，本领域技术人员可根据具体实际需求进行选择。
作为示例，电池可以组装成电池模块，电池模块所含电池的数量可以为一个或多个，具体数量本领域技术人员可根据电池模块的应用和容量进行选择。图7是作为一个示例的电池模块4。参照图7，在电池模块4中，多个电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个电池5进行固定。电池模块4还可以包括具有容纳空间的外壳，多个电池5容纳于该容纳空间。
作为示例，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以为一个或多个，具体数量本领域技术人员可根据电池包的应用和容量进行选择。图8和图9是作为一个示例的电池包1。参照图8和图9，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2能够盖设于下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
在本申请的一些实施例中，该电池可以为锂离子电池，正极极片的正极活性材料可以包括磷酸铁锂、镍钴锰三元材料、钴酸锂、锰酸锂、镍酸锂、钒酸锂等中的一种或多种。
在本申请的一些实施例中，负极极片的负极活性材料可以包括石墨、硅基负极材料、中间相碳微球、硬碳、软碳等中的一种或多种。
在本申请的一些实施例中，正极极片和负极极片中可以包括导电剂和粘结剂，其中，正极极片中的导电剂和负极极片中的导电剂可以各自独立地包括碳纳米管、碳黑、碳纤维、石墨烯等中的一种或多种，正极极片中的粘结剂和负极极片中的粘结剂可以各自独立地包 括聚乙烯醇、聚氨酯、聚丙烯酸酯、聚偏二氟乙烯、丁腈橡胶、环氧树脂、醋酸乙烯树脂、氯化橡胶等中的一种或多种。
在本申请的又一方面，本申请提出了一种用电装置。在本申请的一些实施例中，该用电装置包括前面所述的电池。由此，该用电装置具有前面所述的电池所具有的全部特征以及优点，在此不再赘述。
电池、电池模块或电池包可以用作用电装置的电源，也可以用作用电装置的能量存储单元。用电装置可以包括移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等，但不限于此。用电装置可以根据其使用需求来选择电池、电池模块或电池包。
作为示例，图10是作为一个示例的用电装置。该用电装置为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对电池的高功率和高能量密度的需求，可以采用电池包或电池模块。
作为示例，用电装置还可以是手机、平板电脑、笔记本电脑等。该装置通常要求轻薄化，可以采用电池作为电源。
下面通过具体的实施例对本申请进行说明，本领域技术人员能够理解的是，下面的具体实施例仅仅是为了说明的目的，而不以任何方式限制本申请的范围。另外，在下面的实施例中，除非特别说明，所采用的材料和设备均是市售可得的。如果在后面的实施例中，未对具体的处理条件和处理方法进行明确描述，则可以采用本领域中公知的条件和方法进行处理。
实施例1
提供第一基材，第一基材的材料为聚酰亚胺，第一基材的厚度为8微米；在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入马来酸酐单体(第一单体)、第二单体季戊四醇三丙烯酸酯和引发剂偶氮二异丁腈，其中，电解液、马来酸酐单体、季戊四醇三丙烯酸酯、偶氮二异丁腈的质量比为70:20:10:0.2，常温下搅拌6h，混合均匀，得到中间层前驱液；将中间层前驱液涂覆在第一基材的一侧表面，形成厚度为3微米的中间层前驱液涂覆层，在中间层前驱液涂覆层远离第一基材的一侧表面贴合第二基材，第二基材的材料为聚酰亚胺，第二基材的厚度为8微米，加热处理，加热处理的温度为70℃，保温时间为10h，得到隔离膜。
加热处理过程中，中间层前驱液中的部分组分微交联固化(主要为季戊四醇三丙烯酸酯的固化)，电解液微凝胶化，得到的隔离膜的中间层具有微交联结构，微凝胶化的电解液可以承担离子传导功能。
隔离膜中，第一单体的质量含量为10wt％。
实施例2
提供第一基材，第一基材的材料为聚酰亚胺，第一基材的厚度为8微米，在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入马来酸酐单体(第一单体)、表面含有碳碳双键官能团的无机填料SiO2和聚噻吩基苯氧基聚合物(寡聚物)，其中，电解液、马来酸酐单体、无机填料SiO2和聚噻吩基苯氧基聚合物的质量比为70:15:15:1.5，常温下搅拌6h，混合均匀，得到中间层前驱液；将中间层前驱液涂覆在第一基材的一侧表面，形成厚度为5微米的中间层前驱液涂覆层，在中间层前驱液涂覆层远离第一基材的一侧表面贴合第二基材，第二基材的材料为聚酰亚胺，第二基材的厚度为8微米，加热处理，加热处理的温度为70℃，保温时间为10h，得到隔离膜。
隔离膜中，第一单体的质量含量为10wt％，无机填料的质量含量为10wt％，寡聚物的质量含量为1wt％。
实施例3
提供第一基材，第一基材的材料为聚酰亚胺，第一基材的厚度为8微米；在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入马来酸酐单体(第一单体)、第二单体季戊四醇三丙烯酸酯和引发剂偶氮二异丁腈，其中，电解液、马来酸酐单体、季戊四醇三丙烯酸酯、偶氮二异丁腈的质量比为80:10:10:0.2，常温下搅拌6h，混合均匀，得到中间层前驱液；将中间层前驱液涂覆在第一基材的一侧表面，形成厚度为3微米的中间层前驱液涂覆层，在中间层前驱液涂覆层远离第一基材的一侧表面贴合第二基材，第二基材的材料为聚酰亚胺，第二基材的厚度为8微米，加热处理，加热处理的温度为70℃，保温时间为10h，得到隔离膜。
加热处理过程中，中间层前驱液中的部分组分微交联固化(主要为季戊四醇三丙烯酸酯的固化)，电解液微凝胶化，得到的隔离膜的中间层具有微交联结构，微凝胶化的电解液可以承担离子传导功能。
隔离膜中，第一单体的质量含量为5wt％。
实施例4
提供第一基材，第一基材的材料为聚酰亚胺，第一基材的厚度为8微米；在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入马来酸酐单体(第一单体)、第二单体季戊四醇三丙烯酸酯和引发剂偶氮二异丁腈，其中，电解液、马来酸酐单体、季戊四醇三丙烯酸酯、偶氮二异丁腈的质量比为60:30:10:0.2，常温下搅拌6h，混合均匀，得到中间层前驱液；将中间层前驱液涂覆在第一基材的一侧表面，形成厚度为3微米的中间层前驱液涂覆层，在中间层前驱液涂覆层远离第一基材的一侧表面贴合第二基 材，第二基材的材料为聚酰亚胺，第二基材的厚度为8微米，加热处理，加热处理的温度为70℃，保温时间为10h，得到隔离膜。
加热处理过程中，中间层前驱液中的部分组分微交联固化(主要为季戊四醇三丙烯酸酯的固化)，电解液微凝胶化，得到的隔离膜的中间层具有微交联结构，微凝胶化的电解液可以承担离子传导功能。
隔离膜中，第一单体的质量含量为15wt％。
实施例5
提供第一基材，第一基材的材料为聚酰亚胺，第一基材的厚度为8微米；在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入马来酸酐单体(第一单体)、第二单体季戊四醇三丙烯酸酯和引发剂偶氮二异丁腈，其中，电解液、马来酸酐单体、季戊四醇三丙烯酸酯、偶氮二异丁腈的质量比为50:40:10:0.2，常温下搅拌6h，混合均匀，得到中间层前驱液；将中间层前驱液涂覆在第一基材的一侧表面，形成厚度为3微米的中间层前驱液涂覆层，在中间层前驱液涂覆层远离第一基材的一侧表面贴合第二基材，第二基材的材料为聚酰亚胺，第二基材的厚度为8微米，加热处理，加热处理的温度为70℃，保温时间为10h，得到隔离膜。
加热处理过程中，中间层前驱液中的部分组分微交联固化(主要为季戊四醇三丙烯酸酯的固化)，电解液微凝胶化，得到的隔离膜的中间层具有微交联结构，微凝胶化的电解液可以承担离子传导功能。
隔离膜中，第一单体的质量含量为20wt％。
实施例6
与实施例1不同的是，加热处理的温度为60℃，保温时间为20h。其余参数和步骤与实施例1相同。
实施例7
与实施例1不同的是，马来酸酐单体替换为2-氯马来酸酐单体。隔离膜中，2-氯马来酸酐单体的质量含量为10wt％。其余参数和步骤与实施例1相同。
实施例8
与实施例2不同的是，加热处理的温度为60℃。其余参数和步骤与实施例2相同。
实施例9
与实施例2不同的是，在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入了马来酸酐单体和表面含有碳碳双键官能团的无机填料SiO2，未添加寡聚物，其中，电解液、马来酸酐单体(第一单体)和无机填料SiO2的质量比为62.5:15:22.5。隔离膜中，第一单体的质量含量为10wt％，无机填料的质量含量为15wt％。 其余参数和步骤与实施例2相同。
实施例10
与实施例2不同的是，在电解液(碳酸甲乙酯、氟代碳酸乙烯酯、双氟磺酰亚胺锂盐的质量比为3:2:1)中加入了马来酸酐单体和聚噻吩基苯氧基聚合物，未添加无机填料，其中，电解液、马来酸酐单体(第一单体)和聚噻吩基苯氧基聚合物(寡聚物)的质量比为85:15:1.5，中间层前驱液涂覆层的厚度为3微米。隔离膜中，第一单体的质量含量为10wt％，寡聚物的质量含量为1wt％。其余参数和步骤与实施例2相同。
实施例11
与实施例2不同的是，电解液、马来酸酐单体(第一单体)、无机填料SiO2和聚噻吩基苯氧基聚合物(寡聚物)的质量比为55:15:30:1.5，中间层前驱液涂覆层的厚度为6微米。隔离膜中，第一单体的质量含量为10wt％，无机填料的质量含量为20wt％，寡聚物的质量含量为1wt％。其余参数和步骤与实施例2相同。
实施例12
与实施例2不同的是，电解液、马来酸酐单体(第一单体)、无机填料SiO2和聚噻吩基苯氧基聚合物(寡聚物)的质量比为83.5:15:1.5:1.5，中间层前驱液涂覆层的厚度为4微米。隔离膜中，第一单体的质量含量为10wt％，无机填料的质量含量为1wt％，寡聚物的质量含量为1wt％。其余参数和步骤与实施例2相同。
实施例13
与实施例2不同的是，电解液、马来酸酐单体(第一单体)、无机填料SiO2和聚噻吩基苯氧基聚合物(寡聚物)的质量比为70:15:15:15。隔离膜中，第一单体的质量含量为10wt％，无机填料的质量含量为10wt％，寡聚物的质量含量为10wt％。其余参数和步骤与实施例2相同。
实施例14
与实施例2不同的是，电解液、马来酸酐单体(第一单体)、无机填料SiO2和聚噻吩基苯氧基聚合物(寡聚物)的质量比为70:15:15:0.15。隔离膜中，第一单体的质量含量为10wt％，无机填料的质量含量为10wt％，寡聚物的质量含量为0.1wt％。其余参数和步骤与实施例2相同。
对比例1
与实施例1不同的是，电解液中未添加马来酸酐，电解液、季戊四醇三丙烯酸酯、偶氮二异丁腈的质量比为90:10:0.2。隔离膜中，第一单体的质量含量为0。其余参数和步骤与实施例1相同。
对比例2
由一个聚酰亚胺基材形成隔离膜，厚度为13微米。
电池的制备：
正极极片制备：将正极活性材料NCM811(正极活性材料中，镍、钴、锰的摩尔比为8:1:1)、粘结剂聚偏二氟乙烯(PVDF)、导电剂(乙炔黑)加入一定量的N-甲基吡咯烷酮(NMP)中，正极活性材料：粘结剂：导电剂的质量比例为9:0.5:0.5，在干燥房中搅拌制成均匀的正极浆料，控制粘度为3000mPa·S-10000mPa·S，在铝箔上涂覆上述正极浆料，经过烘干处理得到正极极片。对正极极片进行压实处理，正极极片的压实密度为3.4g/cm3。
负极极片制备：将负极活性材料石墨、羧甲基纤维素钠(CMC)、丁苯橡胶(SBR)、导电剂(碳纤维)加入一定量的去离子水中，石墨：羧甲基纤维素钠：丁苯橡胶：导电剂的质量比例为9:0.3:0.2:0.5，搅拌制成均匀的负极浆料，控制粘度为3000mPa·S-10000mPa·S，在铜箔上涂覆上述负极浆料，经过烘干处理得到负极极片。对负极极片进行压实处理，负极极片的压实密度为1.5g/cm3。
将制备好的正极极片、负极极片和隔离膜(实施例1-14或对比例1-2中的隔离膜)按照Z字型叠片结构制成相应电芯，将电芯在90℃的环境下真空烘干12h，随后进行正负极极耳超声焊接，正极采用铝极耳，负极采用镍极耳，正负极极耳位于电芯同侧，将极耳焊接后的电芯装入合适尺寸的铝塑膜中进行顶侧封封装，顶侧封温度为145℃，注液(电池的电解液由碳酸甲乙酯、氟代碳酸乙烯酯和双氟磺酰亚胺锂盐组成，碳酸甲乙酯：氟代碳酸乙烯酯：双氟磺酰亚胺锂盐的质量比为3:2:1)，静置，化成，老化，排气，二封，容量测试即可得到制备好的软包叠片电池。
测试各实施例和对比例的隔离膜中第一单体、无机填料、寡聚物的质量含量，各实施例和对比例的隔离膜在不同温度下的孔隙率以及电池的热失控数据，并将测试结果记录于表1中。
隔离膜中各组分的质量含量测试方法：
将隔离膜的初始总质量记为A。
隔离膜中电解液的质量含量测试：采用抽真空的方法，隔离膜在40℃，真空度-0.1Mpa下，保持20h后，剩余质量记为B，则(A-B)/A的比值记为电解液的质量含量。
隔离膜中无机填料的质量含量测试方法：将隔离膜燃烧(空气气氛下，温度不低于800摄氏度的环境下)后的质量记为C，则C/A的比值记为无机填料的质量含量。
第一单体、寡聚物的质量含量测试方法：将隔离膜上的中间层刮下来，然后对刮下来的物质采用高效液相色谱法测定第一单体和寡聚物的质量，分别记为D和E。则D/A与E/A的比值分别记为第一单体的质量含量和寡聚物的质量含量。
将隔离膜上的中间层刮下来，剩余为隔离膜基材，其质量记为F。
第二单体的质量含量：(A-B-C-D-E-F)/A的比值记为第二单体的质量含量。
隔离膜孔隙率的具体测试方法可参照GB/T 21650.2-2008《压汞法和气体吸附法测定固体材料孔径分布和孔隙度第2部分：气体吸附法分析介孔和大孔》。
电池热失控测试方法：热箱测试：将电池放在高温箱中，高温箱以1℃/min的速率升温，120℃开始，每5℃保温30min，直到电池失效(失效标准为起火或者爆炸)。若电池在A温度下未失效则视为通过A温度热箱测试，则该电池热箱温度大于A温度。
表1隔离膜中各组分的质量含量、隔离膜孔隙率及电池热失控测试结果
通过表1可以看出，实施例1-14中，隔离膜的中间层中具有第一单体，在较低温度下，隔离膜具有较高的孔隙率，在较高温度下，隔离膜中的第一单体聚合，从而阻塞隔离膜的孔隙，使隔离膜的孔隙率显著降低，从而抑制高温下离子的传导，缓解较高温度下正负离 子交换产生的持续升温问题。而对比例1和2中，由于没有添加第一单体，隔离膜在第一温度和第二温度下的孔隙率相差较小，在较高的第二温度下，隔离膜的孔隙率较高，电池热失控测试的热箱温度均较低。
实施例1、实施例3-5相比，可以看出，在一定范围内，隔离膜中第一单体的含量越高，在较高温度下隔离膜的孔隙率越低，电池热失控测试的热箱温度越高。
实施例2、实施例13和实施例14相比，隔离膜中寡聚物的含量越高，第一温度下的孔隙率越高，第二温度下的孔隙率越低，电池热失控测试的热箱温度越高。
实施例11和实施例12相比，隔离膜中无机填料的含量越高，第一温度下的孔隙率越高，第二温度下的孔隙率越低，电池热失控测试的热箱温度越高。
实施例1和实施例6相比，实施例6中加热处理温度较低，隔离膜在第一温度下的孔隙率较高。实施例2和实施例8相比，实施例8中加热温度较低，隔离膜在第一温度下的孔隙率较高。
在本说明书的描述中，参考术语“一个实施例”、“另一个实施例”、“一些实施例”、“另一些实施例”等的描述意指结合该实施例描述的具体特征、结构、材料或者特点包含于本申请的至少一个实施例中。在本说明书中，对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。另外，需要说明的是，本说明书中，术语“第一”、“第二”、“第三”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。
尽管上面已经示出和描述了本申请的实施例，可以理解的是，上述实施例是示例性的，不能理解为对本申请的限制，本领域的普通技术人员在本申请的范围内可以对上述实施例进行变化、修改、替换和变型。

Claims (17)

  1. 一种隔离膜，其中，包括：第一基材，以及位于所述第一基材至少一侧的中间层，所述隔离膜在第一温度下的孔隙率为a，所述隔离膜在第二温度下的孔隙率为b，所述第一温度为-20℃～100℃，40％≤a≤70％，所述第二温度不低于120℃，b≤2％。
  2. 根据权利要求1所述的隔离膜，其中，第三温度为-20℃～120℃，在所述第三温度下，所述中间层包括第一单体，所述第一单体满足以下条件的至少一种：
    所述第一单体的分子中含有环状结构，所述环状结构的原子数小于等于7，所述环状结构上具有第一官能团；
    所述第一单体的分子量不低于90；
    所述第一单体的聚合温度不低于120℃。
  3. 根据权利要求2所述的隔离膜，其中，基于所述隔离膜的总质量，所述第一单体的质量含量为0.1wt％-20wt％。
  4. 根据权利要求2或3所述的隔离膜，其中，所述中间层进一步包括无机填料，所述无机填料满足以下条件中的至少一种：
    所述无机填料包括惰性无机填料，所述惰性无机填料包括二氧化硅、二氧化钛、氧化锌、氧化锆、氧化镁、氧化钡、三氧化二铝、钛酸钡和氢氧化镁中的至少一种；
    所述无机填料包括活性无机填料，所述活性无机填料包括石榴石型固态电解质、钙钛矿型固态电解质、反钙钛矿型固态电解质、钠超离子导体型固态电解质和锂磷氮氧型固态电解质中的至少一种；
    所述无机填料的表面具有第二官能团，所述第二官能团包括氨基、环氧基、碳碳双键、醛基、羟基、糠酯基、酰亚胺基和异腈酸酯基中的至少一种。
  5. 根据权利要求4所述的隔离膜，其中，基于所述隔离膜的总质量，所述无机填料的质量含量为1wt％-20wt％。
  6. 根据权利要求2-5中任一项所述的隔离膜，其中，所述中间层进一步包括寡聚物，所述寡聚物含有稳定自由基，所述寡聚物满足以下条件中的至少之一：
    所述寡聚物是由2-20个重复单元所组成的聚合物；
    所述寡聚物的分子量为200-10000；
    所述稳定自由基包括三苯甲基、硝基和氮氧化物自由基中的至少一种。
  7. 根据权利要求6所述的隔离膜，其中，所述氮氧化物自由基包括4-羟基-2,2,6,6-四甲基哌啶-N-氧单体、聚-2,2,6,6-四甲基哌啶-4-甲基丙烯酸酯-1-氮氧自由基和2,2,6,6-四甲基-哌啶氮氧自由基中的至少一种。
  8. 根据权利要求6或7所述的隔离膜，其中，所述寡聚物包括聚噻吩基苯氧基聚合物、芳基甲基自由基聚合物、氮氧自由基官能化聚丙烯胺树枝状聚合物、共轭自由基聚合物、梳状氮氧自由基聚合物、聚乙烯胺负载的氮氧自由基聚合物和聚乙烯胺负载的硝基自由基聚合物中的至少一种。
  9. 根据权利要求6-8中任一项所述的隔离膜，其中，基于所述隔离膜的总质量，所述寡聚物的质量含量为0.1wt％-10％wt。
  10. 根据权利要求1-9中任一项所述的隔离膜，其中，进一步包括第二基材，所述第二基材位于所述中间层远离所述第一基材的一侧。
  11. 根据权利要求10所述的隔离膜，其中，所述第一基材和所述第二基材各自独立地包括聚酰胺、聚酰胺酰亚胺、聚酮、聚砜、聚苯硫醚、聚苯醚、聚偏二氟乙烯、聚四氟乙烯、聚氯乙烯、聚烯烃、全氟烷氧基烷烃、聚酯、液晶聚合物、聚甲醛、丙烯腈苯乙烯丙烯酸酯、苯乙烯丙烯腈、丙烯腈丁二烯苯乙烯、聚苯并咪唑、聚对苯撑共聚物、聚丙烯腈、聚乙烯亚胺、乙烯四氟乙烯、聚氯三氟乙烯、芳纶、聚醚酰亚胺、聚对苯撑苯并二噁唑和纤维素中的至少一种。
  12. 一种制备权利要求1-11中任一项所述的隔离膜的方法，其中，包括：
    提供第一基材；
    制备中间层前驱液，所述中间层前驱液包括电解液和第一单体；
    将所述中间层前驱液涂覆在所述第一基材的至少一侧表面，形成中间层前驱液涂覆层，加热处理，得到隔离膜。
  13. 根据权利要求12所述的方法，其中，在所述加热处理之前进一步包括：在所述中间层前驱液涂覆层远离所述第一基材的一侧设置第二基材。
  14. 根据权利要求12或13所述的方法，其中，所述中间层前驱液进一步包括无机填料、寡聚物、第二单体和引发剂中的至少一种。
  15. 根据权利要求14所述的方法，其中，满足以下条件中的至少之一：
    所述电解液包括碳酸甲乙酯、氟代碳酸乙烯酯和双氟磺酰亚胺锂盐；
    所述第二单体包括季戊四醇三丙烯酸酯；
    所述加热处理的温度为60℃-70℃；
    所述加热处理的时间为1h-20h。
  16. 一种电池，其中，包括正极极片、负极极片，以及位于所述正极极片和所述负极极片之间的隔离件，所述隔离件包括权利要求1-11中任一项所述的隔离膜或利用权利要求12-15中任一项所述的方法制备的隔离膜。
  17. 一种用电装置，其中，包括权利要求16所述的电池。
PCT/CN2023/134693 2023-04-27 2023-11-28 隔离膜及其制备方法、电池和用电装置 Ceased WO2024221900A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202310473685.0A CN118867577A (zh) 2023-04-27 2023-04-27 隔离膜及其制备方法、电池和用电装置
CN202310473685.0 2023-04-27

Publications (1)

Publication Number Publication Date
WO2024221900A1 true WO2024221900A1 (zh) 2024-10-31

Family

ID=93174033

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/134693 Ceased WO2024221900A1 (zh) 2023-04-27 2023-11-28 隔离膜及其制备方法、电池和用电装置

Country Status (2)

Country Link
CN (1) CN118867577A (zh)
WO (1) WO2024221900A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120261907A (zh) * 2025-04-14 2025-07-04 厦门笃正电子技术有限公司 一种高浸润性长循环锂电复合隔膜及其制备方法与应用

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120149733A (zh) * 2025-03-13 2025-06-13 江苏厚生新能源科技股份有限公司 一种高耐热性高离子电导率锂离子电池隔膜及其制备方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102160211A (zh) * 2008-08-19 2011-08-17 帝人株式会社 非水系二次电池用隔板
CN103113607A (zh) * 2013-01-21 2013-05-22 青岛中科华联新材料有限公司 一种具有高温自增强机制的微孔聚合物隔膜的制备方法
CN110311138A (zh) * 2019-07-11 2019-10-08 安普瑞斯（无锡）有限公司 一种具有热动保护功能的锂离子二次电池
CN111834591A (zh) * 2019-04-18 2020-10-27 比亚迪股份有限公司 多孔隔膜及其制备方法和锂离子电池
CN115832623A (zh) * 2022-10-14 2023-03-21 宁德时代新能源科技股份有限公司 隔离膜及其制备方法、二次电池和用电装置
CN115939516A (zh) * 2022-12-13 2023-04-07 国网湖南省电力有限公司 一种分级式阻断热失控的锂离子电池及其制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102160211A (zh) * 2008-08-19 2011-08-17 帝人株式会社 非水系二次电池用隔板
CN103113607A (zh) * 2013-01-21 2013-05-22 青岛中科华联新材料有限公司 一种具有高温自增强机制的微孔聚合物隔膜的制备方法
CN111834591A (zh) * 2019-04-18 2020-10-27 比亚迪股份有限公司 多孔隔膜及其制备方法和锂离子电池
CN110311138A (zh) * 2019-07-11 2019-10-08 安普瑞斯（无锡）有限公司 一种具有热动保护功能的锂离子二次电池
CN115832623A (zh) * 2022-10-14 2023-03-21 宁德时代新能源科技股份有限公司 隔离膜及其制备方法、二次电池和用电装置
CN115939516A (zh) * 2022-12-13 2023-04-07 国网湖南省电力有限公司 一种分级式阻断热失控的锂离子电池及其制备方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120261907A (zh) * 2025-04-14 2025-07-04 厦门笃正电子技术有限公司 一种高浸润性长循环锂电复合隔膜及其制备方法与应用
CN120261907B (zh) * 2025-04-14 2026-06-26 厦门笃正新能源股份有限公司 一种高浸润性长循环锂电复合隔膜及其制备方法与应用

Also Published As

Publication number Publication date
CN118867577A (zh) 2024-10-29

Similar Documents

Publication Publication Date Title
CN115810873B (zh) 电池组件、电池单体、二次电池和用电装置
CN103636051B (zh) 新型聚合物电解质和包含其的锂二次电池
CN103620850B (zh) 具有新型结构的电极组件和使用其的二次电池
CN111785925A (zh) 极片及应用、含有该极片的低温升高安全性锂离子电池
CN111430795B (zh) 一种电化学装置及包括其的电子装置
KR20240005895A (ko) 음극 시트 및 이의 제조 방법, 이차 전지, 전지 모듈, 전지 팩 및 전기 장치
WO2021023136A1 (zh) 电化学储能装置和设备
CN118867577A (zh) 隔离膜及其制备方法、电池和用电装置
CN111600075A (zh) 一种辐照提高锂电池负极极片中粘结剂耐电解液性能的方法
CN112018446B (zh) 一种适用于硅碳体系锂离子电池的电解液
WO2023098381A1 (zh) 二次电池及包含其的用电装置
US20250323324A1 (en) Electrochemical apparatus and electronic apparatus
WO2025035655A1 (zh) 一种电池外壳及其制备方法、组成的二次电池、用电装置
CN115820013B (zh) 电池外壳及其制备方法、二次电池和用电装置
WO2024229731A1 (zh) 二次电池和用电装置
CN119522508A (zh) 隔膜、二次电池及用电装置
CN115832614A (zh) 一种隔膜及二次电池和用电装置
CN119208506B (zh) 负极极片、其制备方法、二次电池和用电装置
WO2026000732A1 (zh) 电池单体及其制备方法、电池和用电装置
CN118173764B (zh) 正极材料及其制备方法、电极组件、锂离子电池和用电装置
JP7709539B2 (ja) 電解液、二次電池、電池モジュール、電池パック及び電力消費装置
CN117254115A (zh) 用于高电压锂离子电池的电解质
CN118738265A (zh) 正极极片及包含其的二次电池、用电装置
CN118299503B (zh) 电极极片、其制备方法及包含其的二次电池和用电装置
JP7729692B2 (ja) 架橋時間が短縮されたゲルポリマー電解質組成物、それを含む二次電池および上記二次電池の製造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23935068

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 23935068

Country of ref document: EP

Kind code of ref document: A1