WO2024109000A1 - Lithium battery separator and preparation method therefor - Google Patents

Lithium battery separator and preparation method therefor Download PDF

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WO2024109000A1
WO2024109000A1 PCT/CN2023/101217 CN2023101217W WO2024109000A1 WO 2024109000 A1 WO2024109000 A1 WO 2024109000A1 CN 2023101217 W CN2023101217 W CN 2023101217W WO 2024109000 A1 WO2024109000 A1 WO 2024109000A1
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preparation
lithium battery
nano
diaphragm
battery separator
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PCT/CN2023/101217
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French (fr)
Chinese (zh)
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胡天文
李成
李金林
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安徽绿沃循环能源科技有限公司
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Publication of WO2024109000A1 publication Critical patent/WO2024109000A1/en

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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
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/52—Amides or imides
    • C08F220/54—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide
    • C08F220/60—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide containing nitrogen in addition to the carbonamido nitrogen
    • C08F220/606—Amides, e.g. N,N-dimethylacrylamide or N-isopropylacrylamide containing nitrogen in addition to the carbonamido nitrogen and containing other heteroatoms
    • 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
    • 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
    • H01M50/409—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
    • H01M50/423—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
    • H01M50/44—Fibrous material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/446—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
    • H01M50/497—Ionic conductivity
    • 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 invention relates to the technical field of lithium batteries, and in particular to a separator for lithium batteries and a preparation method thereof.
  • Batteries as electrochemical energy storage devices, are widely used in portable smart devices, electric vehicles and other fields.
  • lithium batteries have the advantages of high energy density, long cycle life, low self-discharge rate, no memory effect, stable discharge voltage, fast charging and discharging, and environmental protection. They are widely used in transportation, daily life, medicine, and even space exploration. After nearly 20 years of development, they have been widely recognized by the industry.
  • the lithium battery separator is one of the key internal components of the lithium battery. Its main function is to separate the positive and negative electrodes of the lithium battery to prevent the two electrodes from contacting and short-circuiting. Although the material of the lithium battery separator is not conductive, it has the function of allowing electrolyte ions to pass through. The performance of the separator determines the interface structure and internal resistance of the lithium battery, which directly affects the capacity, cycle and safety performance of the lithium battery.
  • the ideal lithium battery separator should have high ionic conductivity, good thermal stability, chemical stability and electrochemical stability, maintain high wettability to the electrolyte during repeated charge and discharge, and excellent mechanical properties.
  • commercial lithium battery separators are mainly polyolefin microporous membranes made of polyethylene and/or polypropylene.
  • Polyolefin microporous membranes are low-cost, controllable in pore size, have stable chemical stability, good mechanical strength and electrochemical stability, and have high-temperature self-closing properties, ensuring the safety of lithium-ion secondary batteries in daily use.
  • this type of separator has the problems of too high thermal shrinkage and insufficient wettability of the electrolyte. If the shrinkage is too high, the polyolefin film will easily melt under high temperature conditions, causing large-area short circuits and triggering thermal runaway, aggravating heat accumulation, generating high pressure inside the battery, and causing the battery to burn or explode.
  • the polyolefin The microporous membrane has low surface energy and is highly inert and hydrophobic, while the electrolyte solution contains a large amount of polar components, so the two have poor affinity, which increases the battery resistance and affects the battery's cycle performance and charge and discharge efficiency.
  • Chinese invention patent CN102367172B discloses a modified silica and lithium-ion battery polyolefin microporous diaphragm, which is prepared by the following method: blending modified silica with high/ultra-high molecular weight polyolefin, adding ordinary polyolefin, granulating, and obtaining modified masterbatch; mixing the modified masterbatch with polyolefin, melt blending and extruding, forming a diaphragm with a hard elastic structure; continuously stretching the diaphragm, and then heat setting at 100-150°C to obtain a lithium-ion battery polyolefin microporous diaphragm.
  • the lithium-ion battery polyolefin microporous diaphragm of the invention has a low film thickness (less than 15 ⁇ m); good film strength (longitudinal breaking strength greater than 100MPa, transverse breaking strength of about 8MPa, elongation at break 50%); adjustable film porosity and pore structure (porosity greater than 50%, pore size 0.1-1 ⁇ m); and low film thermal shrinkage (less than 5%).
  • This invention can improve the thermal stability of the polymer, however, it still has the problem of insufficient wettability of the electrolyte, which increases the battery resistance and affects the battery's cycle performance and charge and discharge efficiency.
  • the art still needs a lithium battery separator having high ionic conductivity, sufficient electrolyte wettability, excellent aging resistance and heat resistance, and good mechanical properties, and a preparation method thereof.
  • the purpose of the present invention is to overcome the deficiencies of the prior art and to provide a lithium battery diaphragm with high ionic conductivity, sufficient electrolyte wettability, excellent aging resistance and heat resistance, and good mechanical properties, and a preparation method thereof.
  • the present invention provides the following technical solutions:
  • a method for preparing a lithium battery separator comprises the following steps:
  • Step S101 preparation of a copolymer: adding N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), and an initiator to a high boiling point solvent, stirring and reacting at 65-75° C.
  • Step S102 forming the diaphragm: the copolymer prepared in step S101, the amino-terminated hyperbranched polyimide polymer, the sulfonyl-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent are uniformly mixed, and then ground through a 200-400 mesh sieve, and finally the diaphragm is obtained by melt extrusion and heat setting process;
  • Step S103 pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8-13wt% for 18-32 hours, then rinse the membrane with water until the eluent is neutral, to obtain a diaphragm for lithium battery.
  • the mass ratio of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator, and high boiling point solvent in step S101 is (3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35).
  • the initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile.
  • the high boiling point solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.
  • the inert gas is any one of nitrogen, helium, neon and argon.
  • the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate, and coupling agent in step S102 is (40-60):(10-15):(15-20):(5-8):(1-2):(3-5).
  • the amino-terminated hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B.
  • the source of the sulfonyl-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
  • the average diameter of the nano-boron fiber is 300-500 nm, and the aspect ratio is (16-24):1; the particle size of the nano-calcium carbonate is 300-600 nm.
  • the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.
  • the temperature of the melt extrusion process is 340-400° C.
  • the temperature of the heat setting process is 160-230° C.
  • the time of the heat setting process is 40-50 min.
  • the mass ratio of the diaphragm to the hydrochloric acid solution is 1:(25-35).
  • the present invention also provides a lithium battery separator prepared by the preparation method described in the above scheme.
  • the present invention has the following advantages compared with the prior art:
  • the present invention provides a method for preparing a lithium battery diaphragm, which has a simple process, is easy to operate, has low requirements on equipment and reaction conditions, has high preparation efficiency and finished product qualification rate, is suitable for continuous large-scale production and application, and has high economic value, social value and promotion and application value.
  • the present invention provides a lithium battery separator, wherein the component copolymer is prepared by copolymerization of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, and 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazo[3,2-a]quinoline-4-carboxylic acid, so that the separator structure contains cyano, trifluoromethylphenyl, amide, triazone, phenylphosphine, fluorinated piperazine, thiazole, quinoline and other structures at the same time. These structures interact with each other, and under the joint action of electronic effect, steric effect and conjugation effect, the separator has excellent
  • the present invention provides a lithium battery separator, in which the epoxy groups in the copolymer molecular structure can undergo an epoxy ring-opening reaction with the amino groups on the amino-terminated hyperbranched polyimide polymer, and the sulfonic acid groups on the sulfonate-terminated hyperbranched sulfonated polyarylether can easily connect with the quaternary phosphonium salt structure in the copolymer molecular structure by ionic bonds to form a three-dimensional network structure.
  • the advantages of these components are combined to effectively improve the mechanical properties, heat resistance and durability of the membrane.
  • the present invention provides a lithium battery separator, wherein the addition of nano-boron fibers can enhance the mechanical properties and heat resistance of the membrane; the use of nano-calcium carbonate can ensure the porosity of the membrane; and the introduction of lithium salt structure, quaternary phosphite structure and sulfonate anion structure into the membrane structure is beneficial to improving ionic conductivity.
  • the present invention provides a method for preparing a lithium battery separator, comprising the following steps:
  • Step S101 preparation of copolymer: N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazol[3,2-a] Quinoline-4-carboxylic acid (CAS: 84339-01-5) and an initiator are added to a high boiling point solvent, stirred and reacted at 65-75° C.
  • Step S102 forming the diaphragm: the copolymer prepared in step S101, the amino-terminated hyperbranched polyimide polymer, the sulfonyl-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent are uniformly mixed, and then ground through a 200-400 mesh sieve, and finally the diaphragm is obtained by melt extrusion and heat setting process;
  • Step S103 pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8-13wt% for 18-32 hours, then rinse the membrane with water until the eluent is neutral, to obtain a diaphragm for lithium battery.
  • the initiator is preferably at least one of azobisisobutyronitrile and azobisisoheptanenitrile.
  • the high boiling point solvent is preferably at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.
  • the inert gas is preferably any one of nitrogen, helium, neon and argon.
  • the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is preferably (40-60):(10-15):(15-20):(5-8):(1-2):(3-5).
  • the amino-terminated hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B.
  • the sulfonyl-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
  • the average diameter of the nano-boron fiber is preferably 300-500nm, and the aspect ratio is preferably (16-24):1; the particle size of the nano-calcium carbonate is preferably 300-600nm.
  • the coupling agent is preferably at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.
  • the melt extrusion process temperature is preferably 340-400° C.
  • the heat setting process temperature is preferably 160-230° C.
  • the setting time is preferably 40-50 min.
  • the mass ratio of the diaphragm to the hydrochloric acid solution in step S103 is 1:(25-35).
  • the present invention also provides a lithium battery separator prepared by the preparation method described in the above scheme.
  • the preparation method of the amino-terminated hyperbranched polyimide polymer is as follows: 0.629 g (1 mmol) of triamine monomer 2,4,6-tris[4-(4-aminophenoxy)-phenyl]pyridine and 15 mL of N-methylpyrrolidone are added into a four-necked bottle, nitrogen is introduced, the temperature is raised to 40° C., 0.322 g (1 mmol) of 3,3',4,4'-tetracarboxylic acid dianhydride benzophenone is dissolved in 15 mL of N-methylpyrrolidone, the mixture is uniformly added dropwise into the four-necked bottle over 1 to 2 hours, and the reaction is continued for 12 to 16 hours; then 10 mL of m-xylene is added, the temperature is raised to 160 to 170° C., and reflux is maintained for 5 to 8 hours under the action of a water separator, and the reaction liquid is cooled and discharged into ethanol, filtered
  • the preparation method of the sulfonate-terminated hyperbranched sulfonated polyarylether is as follows: 4.1mmol sulfonated 4,4'-difluorobenzophenone, 2mmol bisphenol A, 8mmol potassium carbonate, 15ml N,N-dimethylacetamide (DMAc) and 10ml toluene are added to a container with a reflux device and a water separation device to form a reaction solution, the reaction solution is first refluxed at a constant temperature of 140°C for 10 hours, and then the reaction solution is reacted at a constant temperature of 170°C for 10 hours, then 1.2mmol 1,3,5-trihydroxybenzene is added to the reaction solution, and the reaction is continued at a constant temperature of 170°C for 5 hours, and after cooling to room temperature, the product solution in the container is added dropwise to 150ml of a hydrochloric acid solution with a concentration of 1mol/L for precipitation reaction, and a
  • a method for preparing a lithium battery separator comprises the following steps:
  • Step S101 preparation of a copolymer: N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), and an initiator are added to a high boiling point solvent, stirred and reacted at 65° C.
  • Step S102 forming the diaphragm: the copolymer prepared in step S101, the amino-terminated hyperbranched polyimide polymer, the sulfonyl-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent are uniformly mixed, and then ground through a 200-mesh sieve, and finally the diaphragm is obtained by melt extrusion and heat setting process;
  • Step S103 pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8 wt % for 18 hours, then rinse the membrane with water until the eluent is neutral, to obtain a diaphragm for a lithium battery.
  • step S101 the mass ratio of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator, and high boiling point solvent is 3:1:0.8:0.1:0.06:25; the initiator is azobisisobutyronitrile; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is nitrogen.
  • the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonate-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate, and coupling agent in step S102 is 40:10:15:5:1:3; the amino-terminated hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B; the sulfonate-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
  • the average diameter of the nano-boron fiber is 300nm, and the aspect ratio is 16:1; the particle size of the nano-calcium carbonate is 300nm; the coupling agent is silane coupling agent KH550; the melt extrusion process temperature is 340°C, the heat setting process temperature is 160°C, and the setting time is 40min.
  • the mass ratio of the diaphragm to the hydrochloric acid solution in step S103 is 1:25.
  • a lithium battery separator and a preparation method thereof which is basically the same as that of Example 1, except that the N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-
  • the mass ratio of 5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator and high boiling point solvent is 3.5:1:0.9:0.15:0.065:27; the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-
  • a lithium battery separator and a preparation method thereof which is basically the same as that of Example 1, except that the N-(4-cyano-3-trifluoromethylphenyl)methyl acrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyl triphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazine
  • the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonate-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is 50:13:18:6.5:1.5:4.
  • a lithium battery separator and a preparation method thereof which is basically the same as that of Example 1, except that in step S101, N-(4-cyano-3-trifluoromethylphenyl)methyl acrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyl triphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5
  • the mass ratio of H-thiazolyl[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator, and high boiling point solvent is 4.5:1:1.1:0.25:0.075:33; the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron
  • a lithium battery separator and a preparation method thereof which is substantially the same as that of Example 1, except that in step S101, N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(ethylene oxide)
  • the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is 60:15:20:8:2:5.
  • a lithium battery separator and a preparation method thereof which are basically the same as Example 1, except that 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid is not added.
  • a separator for a lithium battery and a preparation method thereof which are substantially the same as those in Example 1, except that no amino-terminated hyperbranched polyimide polymer is added.
  • the thickness of the lithium battery diaphragm prepared in each example was controlled at 15 ⁇ m, and relevant performance tests were carried out.
  • the maximum force when piercing the diaphragm is recorded as the puncture strength, and the unit is gF (gram-force); the ionic conductivity is measured on an electrochemical workstation (Zahner IM6 EX) using a two-electrode AC impedance method, and the test frequency is 1Hz-1MHz.
  • the lithium battery separator prepared in the embodiment of the present invention has better mechanical properties and temperature resistance than the comparative example, and has higher ionic conductivity, which is the result of the cooperation of various raw materials.

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Abstract

The present invention relates to the technical field of lithium batteries, and in particular to a lithium battery separator and a preparation method therefor. Disclosed in the present invention is a preparation method for a lithium battery separator, comprising the following steps: S101, preparation of a copolymer; step S102, forming of a separator: uniformly mixing the copolymer prepared in step S101, an amino-terminated hyperbranched polyimide polymer, sulfo-terminated hyperbranched sulfonated polyarylether, nano boron fibers, nano calcium carbonate and a coupling agent, grinding the mixture and sieving same by a 200-400 mesh sieve, and finally obtaining the separator by means of a melt extrusion and heat setting process; and step S103, hole making. Further disclosed in the present invention is a lithium battery separator. The lithium battery separator disclosed in the present invention has high ionic conductivity, sufficient electrolyte wettability, excellent aging resistance and heat resistance, and good mechanical properties.

Description

一种锂电池用隔膜及其制备方法A lithium battery diaphragm and preparation method thereof
本申请要求于2022年11月24日提交中国专利局、申请号为CN202211481549.8、发明名称为“一种锂电池用隔膜及其制备方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application filed with the China Patent Office on November 24, 2022, with application number CN202211481549.8 and invention name “A diaphragm for lithium batteries and its preparation method”, all contents of which are incorporated by reference in this application.
技术领域Technical Field
本发明涉及锂电池技术领域，尤其涉及一种锂电池用隔膜及其制备方法。The present invention relates to the technical field of lithium batteries, and in particular to a separator for lithium batteries and a preparation method thereof.
背景技术Background technique
随着现代电子工业的不断进步，储能设备的应用范围越来越广。电池作为电化学储能设备，广泛应用于便携智能设备、电动汽车等多个领域。锂电池作为较为常见的电池之一，由于其具有能量密度高、循环寿命长、自放电率低、无记忆效应、放电电压稳定、充放电快速和环保等优点，在交通工具、日常生活、医学、甚至空间探索等领域都用途广泛，经过近二十年的发展，得到了工业界普遍认可。With the continuous progress of the modern electronic industry, the application scope of energy storage equipment is becoming wider and wider. Batteries, as electrochemical energy storage devices, are widely used in portable smart devices, electric vehicles and other fields. As one of the more common batteries, lithium batteries have the advantages of high energy density, long cycle life, low self-discharge rate, no memory effect, stable discharge voltage, fast charging and discharging, and environmental protection. They are widely used in transportation, daily life, medicine, and even space exploration. After nearly 20 years of development, they have been widely recognized by the industry.
锂电池用隔膜是锂电池的关键内层组件之一，其主要作用是使锂电池的正、负极分隔开来，防止两极发生接触而短路；虽然锂电池用隔膜的材质是不导电的，但是具有能使电解质离子通过的功能；隔膜的性能决定了锂电池的界面结构、内阻等，直接影响锂电池的容量、循环以及安全性能等特性。理想的锂电池用隔膜应同时具有较高的离子电导率，良好的热稳定性、化学稳定性和电化学稳定性，反复充放电过程中对电解液保持高度浸润性及优异的机械性能。The lithium battery separator is one of the key internal components of the lithium battery. Its main function is to separate the positive and negative electrodes of the lithium battery to prevent the two electrodes from contacting and short-circuiting. Although the material of the lithium battery separator is not conductive, it has the function of allowing electrolyte ions to pass through. The performance of the separator determines the interface structure and internal resistance of the lithium battery, which directly affects the capacity, cycle and safety performance of the lithium battery. The ideal lithium battery separator should have high ionic conductivity, good thermal stability, chemical stability and electrochemical stability, maintain high wettability to the electrolyte during repeated charge and discharge, and excellent mechanical properties.
目前，商品化的锂电池隔膜主要是以聚乙烯和/或聚丙烯为材料的聚烯烃微孔膜。聚烯烃微孔膜成本低廉、尺寸孔径可控、具有稳定的化学稳定性、良好的机械强度和电化学稳定性，并且具有高温自关闭性能，保证了锂离子二次电池日常使用的安全性能。然而这类隔膜存在热收缩率太高和电解液润湿性不足的问题。收缩率太高，则聚烯烃薄膜在高温条件下容易发生熔解，从而造成大面积短路并引发热失控，加剧热量积累，产生电池内部高气压，引起电池燃烧或爆炸。另一方面，由于聚烯烃链中无极性基团，导致聚烯烃 微孔膜的表面能低，具有很强的惰性和疏水性，而电解质溶液中含有大量的极性成分，故两者亲和性差，使电池电阻增加，电池的循环性能和充放电效率都受到影响。At present, commercial lithium battery separators are mainly polyolefin microporous membranes made of polyethylene and/or polypropylene. Polyolefin microporous membranes are low-cost, controllable in pore size, have stable chemical stability, good mechanical strength and electrochemical stability, and have high-temperature self-closing properties, ensuring the safety of lithium-ion secondary batteries in daily use. However, this type of separator has the problems of too high thermal shrinkage and insufficient wettability of the electrolyte. If the shrinkage is too high, the polyolefin film will easily melt under high temperature conditions, causing large-area short circuits and triggering thermal runaway, aggravating heat accumulation, generating high pressure inside the battery, and causing the battery to burn or explode. On the other hand, since there are no polar groups in the polyolefin chain, the polyolefin The microporous membrane has low surface energy and is highly inert and hydrophobic, while the electrolyte solution contains a large amount of polar components, so the two have poor affinity, which increases the battery resistance and affects the battery's cycle performance and charge and discharge efficiency.
例如，中国发明专利CN102367172B公开了一种改性二氧化硅和锂离子电池聚烯烃微孔隔膜，该隔膜由以下方法制备得到：将改性二氧化硅与高/超高分子量的聚烯烃共混，加入普通聚烯烃，造粒，得到改性母粒；将改性母粒与聚烯烃混合，熔融共混挤出，形成具有硬弹性结构的膜片；对膜片进行连续拉伸，然后在100-150℃下热定型，即得到锂离子电池聚烯烃微孔隔膜。该发明的锂离子电池聚烯烃微孔隔膜膜厚度较低(低于15μm)；膜强度较佳(纵向断裂强度大于100MPa，横向断裂强度约8MPa，断裂伸长率50％)；膜的孔隙率及孔结构可调(孔隙率大于50％，孔径0.1-1μm)；膜热收缩率较小(低于5％)。该发明可提升聚合物热稳定性，然而，其仍然存在电解液润湿性不足的问题，使电池电阻增加，电池的循环性能和充放电效率都受到影响。For example, Chinese invention patent CN102367172B discloses a modified silica and lithium-ion battery polyolefin microporous diaphragm, which is prepared by the following method: blending modified silica with high/ultra-high molecular weight polyolefin, adding ordinary polyolefin, granulating, and obtaining modified masterbatch; mixing the modified masterbatch with polyolefin, melt blending and extruding, forming a diaphragm with a hard elastic structure; continuously stretching the diaphragm, and then heat setting at 100-150°C to obtain a lithium-ion battery polyolefin microporous diaphragm. The lithium-ion battery polyolefin microporous diaphragm of the invention has a low film thickness (less than 15μm); good film strength (longitudinal breaking strength greater than 100MPa, transverse breaking strength of about 8MPa, elongation at break 50%); adjustable film porosity and pore structure (porosity greater than 50%, pore size 0.1-1μm); and low film thermal shrinkage (less than 5%). This invention can improve the thermal stability of the polymer, however, it still has the problem of insufficient wettability of the electrolyte, which increases the battery resistance and affects the battery's cycle performance and charge and discharge efficiency.
本领域仍然需要一种离子电导率高，电解液润湿性足，耐老化性和耐热性优异，机械力学性能好的锂电池用隔膜及其制备方法。The art still needs a lithium battery separator having high ionic conductivity, sufficient electrolyte wettability, excellent aging resistance and heat resistance, and good mechanical properties, and a preparation method thereof.
发明内容Summary of the invention
本发明目的是为了克服现有技术的不足而提供一种离子电导率高，电解液润湿性足，耐老化性和耐热性优异，机械力学性能好的锂电池用隔膜及其制备方法。The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a lithium battery diaphragm with high ionic conductivity, sufficient electrolyte wettability, excellent aging resistance and heat resistance, and good mechanical properties, and a preparation method thereof.
为达到上述目的，本发明提供以下技术方案：In order to achieve the above object, the present invention provides the following technical solutions:
一种锂电池用隔膜的制备方法，包括如下步骤：A method for preparing a lithium battery separator comprises the following steps:
步骤S101、共聚物的制备：将N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂加入到高沸点溶剂中，在惰性气体氛围，65-75℃下搅拌反应4-6小时，后在质量百分浓度为10-20wt％的氢氧化锂溶液中沉出，并用乙醇洗涤沉出的聚合物3-6次，最后旋蒸除去乙醇，得到共聚物； Step S101, preparation of a copolymer: adding N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), and an initiator to a high boiling point solvent, stirring and reacting at 65-75° C. in an inert gas atmosphere for 4-6 hours, and then precipitating in a lithium hydroxide solution with a mass percentage concentration of 10-20wt%, and washing the precipitated polymer with ethanol for 3-6 times, and finally removing the ethanol by rotary evaporation to obtain a copolymer;
步骤S102、隔膜的成型：将经过步骤S101制成的共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂混合均匀后，碾磨过200-400目筛，后经熔挤和热定型工艺最终获得隔膜；Step S102, forming the diaphragm: the copolymer prepared in step S101, the amino-terminated hyperbranched polyimide polymer, the sulfonyl-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent are uniformly mixed, and then ground through a 200-400 mesh sieve, and finally the diaphragm is obtained by melt extrusion and heat setting process;
步骤S103、制孔：将经过步骤S102制成的隔膜浸泡在质量分数为8-13wt％的盐酸溶液中18-32小时，后用水冲洗膜至洗脱液呈中性，得到锂电池用隔膜。Step S103, pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8-13wt% for 18-32 hours, then rinse the membrane with water until the eluent is neutral, to obtain a diaphragm for lithium battery.
优选的，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂、高沸点溶剂的质量比为(3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35)。Preferably, the mass ratio of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator, and high boiling point solvent in step S101 is (3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35).
优选的，所述引发剂为偶氮二异丁腈和偶氮二异庚腈中的至少一种。Preferably, the initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile.
优选的，所述高沸点溶剂为二甲亚砜、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺和N-甲基吡咯烷酮中的至少一种。Preferably, the high boiling point solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.
优选的，所述惰性气体为氮气、氦气、氖气、氩气中的任意一种。Preferably, the inert gas is any one of nitrogen, helium, neon and argon.
优选的，步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂的质量比为(40-60):(10-15):(15-20):(5-8):(1-2):(3-5)。Preferably, the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate, and coupling agent in step S102 is (40-60):(10-15):(15-20):(5-8):(1-2):(3-5).
优选的，所述氨基封端的超支化聚酰亚胺聚合物的来源无特殊要求，在本发明的一个实施例中，所述氨基封端的超支化聚酰亚胺聚合物是按中国发明专利CN102267940B实施例3的方法制成。Preferably, there is no special requirement for the source of the amino-terminated hyperbranched polyimide polymer. In one embodiment of the present invention, the amino-terminated hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B.
优选的，所述磺基封端超支化磺化聚芳醚的来源无特殊要求，在本发明的一个实施例中，所述磺基封端超支化磺化聚芳醚是按中国发明专利CN109546192A实施例1的方法制成。Preferably, there is no special requirement for the source of the sulfonyl-terminated hyperbranched sulfonated polyarylether. In one embodiment of the present invention, the sulfonyl-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
优选的，所述纳米硼纤维的平均直径为300-500nm，长径比为(16-24):1；所述纳米碳酸钙的粒径为300-600nm。Preferably, the average diameter of the nano-boron fiber is 300-500 nm, and the aspect ratio is (16-24):1; the particle size of the nano-calcium carbonate is 300-600 nm.
优选的，所述偶联剂为硅烷偶联剂KH550、硅烷偶联剂KH560和硅烷偶联剂KH570中的至少一种。 Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.
优选的，步骤S102中所述熔挤工艺温度为340-400℃，热定型工艺的温度为160-230℃，热定型工艺的时间为40-50min。Preferably, in step S102, the temperature of the melt extrusion process is 340-400° C., the temperature of the heat setting process is 160-230° C., and the time of the heat setting process is 40-50 min.
优选的，步骤S103中所述隔膜、盐酸溶液的质量比为1:(25-35)。Preferably, in step S103, the mass ratio of the diaphragm to the hydrochloric acid solution is 1:(25-35).
本发明还提供了前述方案所述制备方法制备得到的锂电池用隔膜。The present invention also provides a lithium battery separator prepared by the preparation method described in the above scheme.
由于上述技术方案运用，本发明与现有技术相比具有下列优点：Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:
(1)本发明提供的一种锂电池用隔膜的制备方法，工艺简单，操作方便，对设备和反应条件要求不高，制备效率和成品合格率高，适合连续规模化生产应用，具有较高的经济价值、社会价值和推广应用价值。(1) The present invention provides a method for preparing a lithium battery diaphragm, which has a simple process, is easy to operate, has low requirements on equipment and reaction conditions, has high preparation efficiency and finished product qualification rate, is suitable for continuous large-scale production and application, and has high economic value, social value and promotion and application value.
(2)本发明提供的一种锂电池用隔膜，组分共聚物是由N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸共聚制成，使得隔膜结构中同时含有氰基、三氟甲基苯基、酰胺基、三嗪酮基、苯基膦基、含氟哌嗪、噻唑、喹啉等结构，这些结构相互作用相互影响，在电子效应、位阻效应和共轭效应的共同作用下，使得制成的隔膜耐老化性和耐热性优异，机械力学性能好。这些极性基团的引入能有效改善电解液润湿性。(2) The present invention provides a lithium battery separator, wherein the component copolymer is prepared by copolymerization of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, and 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazo[3,2-a]quinoline-4-carboxylic acid, so that the separator structure contains cyano, trifluoromethylphenyl, amide, triazone, phenylphosphine, fluorinated piperazine, thiazole, quinoline and other structures at the same time. These structures interact with each other, and under the joint action of electronic effect, steric effect and conjugation effect, the separator has excellent aging resistance and heat resistance, and good mechanical properties. The introduction of these polar groups can effectively improve the wettability of the electrolyte.
(3)本发明提供的一种锂电池用隔膜，共聚物分子结构中的环氧基能与氨基封端的超支化聚酰亚胺聚合物上的氨基发生环氧开环反应，磺基封端超支化磺化聚芳醚上的磺酸基易与共聚物分子结构中的季磷盐结构以离子键连接，形成三维网络结构，且结合了这些组分的优点，有效改善了膜的机械力学性能、耐热性和耐用性。(3) The present invention provides a lithium battery separator, in which the epoxy groups in the copolymer molecular structure can undergo an epoxy ring-opening reaction with the amino groups on the amino-terminated hyperbranched polyimide polymer, and the sulfonic acid groups on the sulfonate-terminated hyperbranched sulfonated polyarylether can easily connect with the quaternary phosphonium salt structure in the copolymer molecular structure by ionic bonds to form a three-dimensional network structure. The advantages of these components are combined to effectively improve the mechanical properties, heat resistance and durability of the membrane.
(4)本发明提供的一种锂电池用隔膜，纳米硼纤维的加入能增强膜的机械力学性能和耐热性；纳米碳酸钙的使用能保证膜的成孔率；膜结构中引入锂盐结构、季磷盐结构和磺酸盐阴离子结构，有利于提高离子电导率。(4) The present invention provides a lithium battery separator, wherein the addition of nano-boron fibers can enhance the mechanical properties and heat resistance of the membrane; the use of nano-calcium carbonate can ensure the porosity of the membrane; and the introduction of lithium salt structure, quaternary phosphite structure and sulfonate anion structure into the membrane structure is beneficial to improving ionic conductivity.
具体实施方式Detailed ways
本发明提供了一种锂电池用隔膜的制备方法，包括如下步骤：The present invention provides a method for preparing a lithium battery separator, comprising the following steps:
步骤S101、共聚物的制备：将N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a] 喹啉-4-羧酸(CAS：84339-01-5)、引发剂加入到高沸点溶剂中，在惰性气体氛围，65-75℃下搅拌反应4-6小时，后在质量百分浓度为10-20wt％的氢氧化锂溶液中沉出，并用乙醇洗涤沉出的聚合物3-6次，最后旋蒸除去乙醇，得到共聚物；Step S101, preparation of copolymer: N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazol[3,2-a] Quinoline-4-carboxylic acid (CAS: 84339-01-5) and an initiator are added to a high boiling point solvent, stirred and reacted at 65-75° C. for 4-6 hours in an inert gas atmosphere, and then precipitated in a lithium hydroxide solution with a mass percentage concentration of 10-20wt%, and the precipitated polymer is washed with ethanol for 3-6 times, and finally the ethanol is removed by rotary evaporation to obtain a copolymer;
步骤S102、隔膜的成型：将经过步骤S101制成的共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂混合均匀后，碾磨过200-400目筛，后经熔挤和热定型工艺最终获得隔膜；Step S102, forming the diaphragm: the copolymer prepared in step S101, the amino-terminated hyperbranched polyimide polymer, the sulfonyl-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent are uniformly mixed, and then ground through a 200-400 mesh sieve, and finally the diaphragm is obtained by melt extrusion and heat setting process;
步骤S103、制孔：将经过步骤S102制成的隔膜浸泡在质量分数为8-13wt％的盐酸溶液中18-32小时，后用水冲洗膜至洗脱液呈中性，得到锂电池用隔膜。Step S103, pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8-13wt% for 18-32 hours, then rinse the membrane with water until the eluent is neutral, to obtain a diaphragm for lithium battery.
在本发明中，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂和高沸点溶剂的质量比优选为(3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35)。In the present invention, the mass ratio of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator and high boiling point solvent in step S101 is preferably (3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35).
在本发明中，所述引发剂优选为偶氮二异丁腈和偶氮二异庚腈中的至少一种。In the present invention, the initiator is preferably at least one of azobisisobutyronitrile and azobisisoheptanenitrile.
在本发明中，所述高沸点溶剂优选为二甲亚砜、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺和N-甲基吡咯烷酮中的至少一种。In the present invention, the high boiling point solvent is preferably at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone.
在本发明中，所述惰性气体优选为氮气、氦气、氖气、氩气中的任意一种。In the present invention, the inert gas is preferably any one of nitrogen, helium, neon and argon.
在本发明中，步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙和偶联剂的质量比优选为(40-60):(10-15):(15-20):(5-8):(1-2):(3-5)。In the present invention, the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is preferably (40-60):(10-15):(15-20):(5-8):(1-2):(3-5).
在本发明中，所述氨基封端的超支化聚酰亚胺聚合物的来源无特殊要求，在本发明的一个实施例中，所述氨基封端的超支化聚酰亚胺聚合物是按中国发明专利CN102267940B实施例3的方法制成。In the present invention, there is no special requirement for the source of the amino-terminated hyperbranched polyimide polymer. In one embodiment of the present invention, the amino-terminated hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B.
在本发明中，所述磺基封端超支化磺化聚芳醚的来源无特殊要求，在本 发明的一个实施例中，所述磺基封端超支化磺化聚芳醚是按中国发明专利CN109546192A实施例1的方法制成。In the present invention, there is no special requirement for the source of the sulfonic group-terminated hyperbranched sulfonated polyarylether. In one embodiment of the invention, the sulfonyl-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
在本发明中，所述纳米硼纤维的平均直径优选为300-500nm，长径比优选为(16-24):1；所述纳米碳酸钙的粒径优选为300-600nm。In the present invention, the average diameter of the nano-boron fiber is preferably 300-500nm, and the aspect ratio is preferably (16-24):1; the particle size of the nano-calcium carbonate is preferably 300-600nm.
在本发明中，所述偶联剂优选为硅烷偶联剂KH550、硅烷偶联剂KH560和硅烷偶联剂KH570中的至少一种。In the present invention, the coupling agent is preferably at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.
在本发明中，所述熔挤工艺温度优选为340-400℃，热定型工艺的温度优选为160-230℃，定型时间优选为40-50min。In the present invention, the melt extrusion process temperature is preferably 340-400° C., the heat setting process temperature is preferably 160-230° C., and the setting time is preferably 40-50 min.
在本发明中，步骤S103中所述隔膜、盐酸溶液的质量比为1:(25-35)。In the present invention, the mass ratio of the diaphragm to the hydrochloric acid solution in step S103 is 1:(25-35).
本发明还提供了上述方案所述制备方法制备得到的锂电池用隔膜。The present invention also provides a lithium battery separator prepared by the preparation method described in the above scheme.
在本发明中，所述氨基封端的超支化聚酰亚胺聚合物的制备方法为：将三胺单体2，4，6-三[4-(4-氨基苯氧基)-苯基]吡啶0.629g(1mmol)和N-甲基吡咯烷酮15mL加入四口瓶中，通入氮气，升温至40℃，将3,3',4,4'-四甲酸二酐二苯酮0.322g(1mmol)溶解到15mLN-甲基吡咯烷酮用1～2h均匀滴加入四口瓶中，然后继续反应12～16h；然后加入间二甲苯10mL，升温至160～170℃，在分水器作用下保持回流5～8h，待反应液冷却后出料在乙醇中，经过滤、去离子水洗涤和真空60℃干燥，得到白色的氨基封端的超支化聚酰亚胺聚合物。In the present invention, the preparation method of the amino-terminated hyperbranched polyimide polymer is as follows: 0.629 g (1 mmol) of triamine monomer 2,4,6-tris[4-(4-aminophenoxy)-phenyl]pyridine and 15 mL of N-methylpyrrolidone are added into a four-necked bottle, nitrogen is introduced, the temperature is raised to 40° C., 0.322 g (1 mmol) of 3,3',4,4'-tetracarboxylic acid dianhydride benzophenone is dissolved in 15 mL of N-methylpyrrolidone, the mixture is uniformly added dropwise into the four-necked bottle over 1 to 2 hours, and the reaction is continued for 12 to 16 hours; then 10 mL of m-xylene is added, the temperature is raised to 160 to 170° C., and reflux is maintained for 5 to 8 hours under the action of a water separator, and the reaction liquid is cooled and discharged into ethanol, filtered, washed with deionized water, and dried at 60° C. in a vacuum to obtain a white amino-terminated hyperbranched polyimide polymer.
在本发明中，所述磺基封端超支化磺化聚芳醚的制备方法为：往带有回流装置和分水装置的容器中加入4.1mmol磺化4,4'-二氟二苯甲酮、2mmol双酚A、8mmol碳酸钾、15mlN,N-二甲基乙酰胺(DMAc)和10ml甲苯形成反应液，先将反应液在140℃下恒温回流10h，再将反应液在170℃温度下恒温反应10h，接着往反应液中加入1.2mmol 1,3,5-三羟基苯，并继续在170℃温度下恒温反应5h，冷却至室温后将容器内的产品溶液逐滴加入至150ml浓度为1mol/L的盐酸溶液中进行沉淀反应，过滤后得到沉淀物，将沉淀物置于温度为100℃的真空干燥箱中干燥18h制得磺基封端超支化磺化聚芳醚，制得的磺基封端超支化磺化聚芳醚的支化度为60％。In the present invention, the preparation method of the sulfonate-terminated hyperbranched sulfonated polyarylether is as follows: 4.1mmol sulfonated 4,4'-difluorobenzophenone, 2mmol bisphenol A, 8mmol potassium carbonate, 15ml N,N-dimethylacetamide (DMAc) and 10ml toluene are added to a container with a reflux device and a water separation device to form a reaction solution, the reaction solution is first refluxed at a constant temperature of 140°C for 10 hours, and then the reaction solution is reacted at a constant temperature of 170°C for 10 hours, then 1.2mmol 1,3,5-trihydroxybenzene is added to the reaction solution, and the reaction is continued at a constant temperature of 170°C for 5 hours, and after cooling to room temperature, the product solution in the container is added dropwise to 150ml of a hydrochloric acid solution with a concentration of 1mol/L for precipitation reaction, and a precipitate is obtained after filtering, and the precipitate is placed in a vacuum drying oven at a temperature of 100°C and dried for 18 hours to obtain the sulfonate-terminated hyperbranched sulfonated polyarylether, and the branching degree of the obtained sulfonate-terminated hyperbranched sulfonated polyarylether is 60%.
下面将结合具体实施例对本发明进行进一步描述，但本发明的保护范围并不仅限于此： The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto:
实施例1Example 1
一种锂电池用隔膜的制备方法，包括如下步骤：A method for preparing a lithium battery separator comprises the following steps:
步骤S101、共聚物的制备：将N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂加入到高沸点溶剂中，在惰性气体氛围，65℃下搅拌反应4小时，后在质量百分浓度为10wt％的氢氧化锂溶液中沉出，并用乙醇洗涤沉出的聚合物3次，最后旋蒸除去乙醇，得到共聚物；Step S101, preparation of a copolymer: N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), and an initiator are added to a high boiling point solvent, stirred and reacted at 65° C. for 4 hours in an inert gas atmosphere, and then precipitated in a lithium hydroxide solution with a mass percentage concentration of 10wt%, and the precipitated polymer was washed with ethanol for 3 times, and finally the ethanol was removed by rotary evaporation to obtain a copolymer;
步骤S102、隔膜的成型：将经过步骤S101制成的共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂混合均匀后，碾磨过200目筛，后经熔挤和热定型工艺最终获得隔膜；Step S102, forming the diaphragm: the copolymer prepared in step S101, the amino-terminated hyperbranched polyimide polymer, the sulfonyl-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent are uniformly mixed, and then ground through a 200-mesh sieve, and finally the diaphragm is obtained by melt extrusion and heat setting process;
步骤S103、制孔：将经过步骤S102制成的隔膜浸泡在质量分数为8wt％的盐酸溶液中18小时，后用水冲洗膜至洗脱液呈中性，得到锂电池用隔膜。Step S103, pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8 wt % for 18 hours, then rinse the membrane with water until the eluent is neutral, to obtain a diaphragm for a lithium battery.
步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂、高沸点溶剂的质量比为3:1:0.8:0.1:0.06:25；所述引发剂为偶氮二异丁腈；所述高沸点溶剂为二甲亚砜；所述惰性气体为氮气。In step S101, the mass ratio of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator, and high boiling point solvent is 3:1:0.8:0.1:0.06:25; the initiator is azobisisobutyronitrile; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is nitrogen.
步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂的质量比为40:10:15:5:1:3；所述氨基封端的超支化聚酰亚胺聚合物是按中国发明专利CN102267940B实施例3的方法制成；所述磺基封端超支化磺化聚芳醚是按中国发明专利CN109546192A实施例1的方法制成。The mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonate-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate, and coupling agent in step S102 is 40:10:15:5:1:3; the amino-terminated hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B; the sulfonate-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
所述纳米硼纤维的平均直径为300nm，长径比为16:1；所述纳米碳酸钙的粒径为300nm；所述偶联剂为硅烷偶联剂KH550；所述熔挤工艺温度为340℃，热定型工艺的温度为160℃，定型时间为40min。The average diameter of the nano-boron fiber is 300nm, and the aspect ratio is 16:1; the particle size of the nano-calcium carbonate is 300nm; the coupling agent is silane coupling agent KH550; the melt extrusion process temperature is 340°C, the heat setting process temperature is 160°C, and the setting time is 40min.
步骤S103中所述隔膜、盐酸溶液的质量比为1:25。 The mass ratio of the diaphragm to the hydrochloric acid solution in step S103 is 1:25.
实施例2Example 2
一种锂电池用隔膜及其制备方法，其与实施例1基本相同，不同的是，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂、高沸点溶剂的质量比为3.5:1:0.9:0.15:0.065:27；步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂的质量比为45:12:17:6:1.2:3.5。A lithium battery separator and a preparation method thereof, which is basically the same as that of Example 1, except that the N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)- The mass ratio of 5H-thiazolo[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator and high boiling point solvent is 3.5:1:0.9:0.15:0.065:27; the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is 45:12:17:6:1.2:3.5.
实施例3Example 3
一种锂电池用隔膜及其制备方法，其与实施例1基本相同，不同的是，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂、高沸点溶剂的质量比为4:1:1:0.2:0.07:30；步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂的质量比为50:13:18:6.5:1.5:4。A lithium battery separator and a preparation method thereof, which is basically the same as that of Example 1, except that the N-(4-cyano-3-trifluoromethylphenyl)methyl acrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyl triphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazine The mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonate-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is 50:13:18:6.5:1.5:4.
实施例4Example 4
一种锂电池用隔膜及其制备方法，其与实施例1基本相同，不同的是，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂、高沸点溶剂的质量比为4.5:1:1.1:0.25:0.075:33；步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂的质量比为58:14:19:7.5:1.8:4.8。A lithium battery separator and a preparation method thereof, which is basically the same as that of Example 1, except that in step S101, N-(4-cyano-3-trifluoromethylphenyl)methyl acrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyl triphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5 The mass ratio of H-thiazolyl[3,2-a]quinoline-4-carboxylic acid (CAS: 84339-01-5), initiator, and high boiling point solvent is 4.5:1:1.1:0.25:0.075:33; the mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate, and coupling agent in step S102 is 58:14:19:7.5:1.8:4.8.
实施例5Example 5
一种锂电池用隔膜及其制备方法，其与实施例1基本相同，不同的是，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷 基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸(CAS：84339-01-5)、引发剂、高沸点溶剂的质量比为5:1:1.2:0.3:0.08:35；步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙、偶联剂的质量比为60:15:20:8:2:5。A lithium battery separator and a preparation method thereof, which is substantially the same as that of Example 1, except that in step S101, N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(ethylene oxide) The mass ratio of the copolymer, amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent in step S102 is 60:15:20:8:2:5.
对比例1Comparative Example 1
一种锂电池用隔膜及其制备方法，其与实施例1基本相同，不同的是，没有添加7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸。A lithium battery separator and a preparation method thereof, which are basically the same as Example 1, except that 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid is not added.
对比例2Comparative Example 2
一种锂电池用隔膜及其制备方法，其与实施例1基本相同，不同的是，没有添加氨基封端的超支化聚酰亚胺聚合物。A separator for a lithium battery and a preparation method thereof, which are substantially the same as those in Example 1, except that no amino-terminated hyperbranched polyimide polymer is added.
为了进一步说明各实施例所涉及的锂电池用隔膜的有益技术效果，对各例制成的锂电池用隔膜厚度控制在15μm，进行相关性能测试，测试方法参见我国现行相应国标，测试结果见表1；其中耐温性以收缩率表示，将正方形的隔膜放入155℃的烘箱中2小时，然后测量隔膜在TD(横向)的收缩比例；穿刺强度：用末端为球面(曲率半径R＝0.5mm)的直径为1.0mm的针，以2.0mm/秒的速度对制备的锂电池隔膜进行刺穿，刺穿隔膜时最大力记为穿刺强度，单位为gF(克力)；离子导电率是采用两电极交流阻抗法在电化学工作站(Zahner IM6 EX)上测得的，测试频率为1Hz-1MHz。In order to further illustrate the beneficial technical effects of the lithium battery diaphragm involved in each embodiment, the thickness of the lithium battery diaphragm prepared in each example was controlled at 15μm, and relevant performance tests were carried out. The test methods refer to the corresponding national standards in my country, and the test results are shown in Table 1; wherein the temperature resistance is expressed as shrinkage rate, and the square diaphragm is placed in an oven at 155°C for 2 hours, and then the shrinkage ratio of the diaphragm in TD (transverse direction) is measured; puncture strength: a needle with a diameter of 1.0mm and a spherical end (radius of curvature R=0.5mm) is used to pierce the prepared lithium battery diaphragm at a speed of 2.0mm/s. The maximum force when piercing the diaphragm is recorded as the puncture strength, and the unit is gF (gram-force); the ionic conductivity is measured on an electrochemical workstation (Zahner IM6 EX) using a two-electrode AC impedance method, and the test frequency is 1Hz-1MHz.
表1
Table 1
从上表可以看出，本发明实施例制备得到的锂电池用隔膜较对比例具有更优异的机械力学性能和耐温性，且离子电导率更高，这是各原料相互配合共同作用的结果。It can be seen from the above table that the lithium battery separator prepared in the embodiment of the present invention has better mechanical properties and temperature resistance than the comparative example, and has higher ionic conductivity, which is the result of the cooperation of various raw materials.
以上所述仅是本发明的优选实施方式，应当指出，对于本技术领域的普 通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。 The above description is only a preferred embodiment of the present invention. It should be noted that the general It is apparent to those skilled in the art that several improvements and modifications may be made without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims (11)

  1. 一种锂电池用隔膜的制备方法，其特征在于，包括如下步骤：A method for preparing a lithium battery separator, characterized in that it comprises the following steps:
    步骤S101、共聚物的制备：将N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸、引发剂加入到溶剂中，在惰性气体氛围，65-75℃下搅拌反应4-6小时，后在质量百分浓度为10-20wt％的氢氧化锂溶液中沉出，并用乙醇洗涤沉出的聚合物3-6次，最后旋蒸除去乙醇，得到共聚物；Step S101, preparation of a copolymer: adding N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphonium bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid, and an initiator to a solvent, stirring and reacting at 65-75° C. in an inert gas atmosphere for 4-6 hours, then precipitating in a lithium hydroxide solution with a mass percentage concentration of 10-20wt%, washing the precipitated polymer with ethanol for 3-6 times, and finally removing the ethanol by rotary evaporation to obtain a copolymer;
    步骤S102、隔膜的成型：将所述步骤S101制成的共聚物与氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙和偶联剂混合均匀后，碾磨过200-400目筛，后经熔挤和热定型工艺最终获得隔膜；Step S102, forming the diaphragm: uniformly mixing the copolymer prepared in step S101 with amino-terminated hyperbranched polyimide polymer, sulfonyl-terminated hyperbranched sulfonated polyarylether, nano-boron fiber, nano-calcium carbonate and coupling agent, grinding through a 200-400 mesh sieve, and finally obtaining the diaphragm through melt extrusion and heat setting processes;
    步骤S103、制孔：将所述步骤S102制成的隔膜浸泡在质量分数为8-13wt％的盐酸溶液中18-32小时，后用水冲洗隔膜至洗脱液呈中性，得到锂电池用隔膜。Step S103, pore making: soak the diaphragm made in step S102 in a hydrochloric acid solution with a mass fraction of 8-13wt% for 18-32 hours, then rinse the diaphragm with water until the eluent is neutral, to obtain a diaphragm for a lithium battery.
  2. 根据权利要求1所述的制备方法，其特征在于，步骤S101中所述N-(4-氰基-3-三氟甲基苯基)甲基丙烯酰胺、1,3-双(环氧乙烷基甲基)-5-(2-丙烯基)-1,3,5-三嗪-2,4,6(1H,3H,5H)-三酮、烯丙基三苯基溴化膦、7-氟-5-氧代-8-(4-(2-丙烯基)-1-哌嗪基)-5H-噻唑并[3,2-a]喹啉-4-羧酸、引发剂、高沸点溶剂的质量比为(3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35)。The preparation method according to claim 1 is characterized in that the mass ratio of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, allyltriphenylphosphine bromide, 7-fluoro-5-oxo-8-(4-(2-propenyl)-1-piperazinyl)-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid, initiator, and high boiling point solvent in step S101 is (3-5):1:(0.8-1.2):(0.1-0.3):(0.06-0.08):(25-35).
  3. 根据权利要求1或2所述的制备方法，其特征在于，所述引发剂为偶氮二异丁腈和偶氮二异庚腈中的至少一种。The preparation method according to claim 1 or 2, characterized in that the initiator is at least one of azobisisobutyronitrile and azobisisoheptanenitrile.
  4. 根据权利要求1或2所述的制备方法，其特征在于，所述高沸点溶剂为二甲亚砜、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺和N-甲基吡咯烷酮中的至少一种；所述惰性气体为氮气、氦气、氖气、氩气中的任意一种。The preparation method according to claim 1 or 2, characterized in that the high boiling point solvent is at least one of dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide and N-methylpyrrolidone; and the inert gas is any one of nitrogen, helium, neon and argon.
  5. 根据权利要求1所述的制备方法，其特征在于，步骤S102中所述共聚物、氨基封端的超支化聚酰亚胺聚合物、磺基封端超支化磺化聚芳醚、纳米硼纤维、纳米碳酸钙和偶联剂的质量比为(40-60):(10-15):(15-20):(5-8):(1-2):(3-5)。The preparation method according to claim 1 is characterized in that the mass ratio of the copolymer, the amino-terminated hyperbranched polyimide polymer, the sulfonate-terminated hyperbranched sulfonated polyarylether, the nano-boron fiber, the nano-calcium carbonate and the coupling agent in step S102 is (40-60):(10-15):(15-20):(5-8):(1-2):(3-5).
  6. 根据权利要求1或5所述的制备方法，其特征在于，所述氨基封端 的超支化聚酰亚胺聚合物是按中国发明专利CN102267940B实施例3的方法制成；所述磺基封端超支化磺化聚芳醚是按中国发明专利CN109546192A实施例1的方法制成。The preparation method according to claim 1 or 5, characterized in that the amino-terminated The hyperbranched polyimide polymer is prepared according to the method of Example 3 of Chinese invention patent CN102267940B; the sulfonyl-terminated hyperbranched sulfonated polyarylether is prepared according to the method of Example 1 of Chinese invention patent CN109546192A.
  7. 根据权利要求1或5所述的制备方法，其特征在于，所述纳米硼纤维的平均直径为300-500nm，长径比为(16-24):1；所述纳米碳酸钙的粒径为300-600nm。The preparation method according to claim 1 or 5 is characterized in that the average diameter of the nano-boron fiber is 300-500nm, and the aspect ratio is (16-24):1; the particle size of the nano-calcium carbonate is 300-600nm.
  8. 根据权利要求1或5所述的制备方法，其特征在于，所述偶联剂为硅烷偶联剂KH550、硅烷偶联剂KH560和硅烷偶联剂KH570中的至少一种。The preparation method according to claim 1 or 5, characterized in that the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570.
  9. 根据权利要求1所述的制备方法，其特征在于，步骤S102中所述熔挤的工艺温度为340-400℃，热定型工艺的温度为160-230℃，热定型工艺的时间为40-50min；The preparation method according to claim 1, characterized in that the process temperature of the melt extrusion in step S102 is 340-400°C, the temperature of the heat setting process is 160-230°C, and the time of the heat setting process is 40-50min;
    步骤S103中所述隔膜与盐酸溶液的质量比为1:(25-35)。The mass ratio of the diaphragm to the hydrochloric acid solution in step S103 is 1:(25-35).
  10. 一种权利要求1-9任一项所述的制备方法制备得到的锂电池用隔膜。A lithium battery separator prepared by the preparation method according to any one of claims 1 to 9.
  11. 根据权利要求10所述的锂电池用隔膜，其特征在于，所述锂电池用隔膜的耐温性＜0.5％，穿刺强度大于615gF，离子导电率大于4.52mS·cm-1。 The lithium battery separator according to claim 10 is characterized in that the temperature resistance of the lithium battery separator is less than 0.5%, the puncture strength is greater than 615 gF, and the ion conductivity is greater than 4.52 mS·cm -1 .
PCT/CN2023/101217 2022-11-24 2023-06-20 Lithium battery separator and preparation method therefor WO2024109000A1 (en)

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