WO2018027652A1 - Separator, preparation method and electrochemical energy storage device - Google Patents

Separator, preparation method and electrochemical energy storage device Download PDF

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Publication number
WO2018027652A1
WO2018027652A1 PCT/CN2016/094313 CN2016094313W WO2018027652A1 WO 2018027652 A1 WO2018027652 A1 WO 2018027652A1 CN 2016094313 W CN2016094313 W CN 2016094313W WO 2018027652 A1 WO2018027652 A1 WO 2018027652A1
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polymer
separator
bonding layer
heat
coating
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PCT/CN2016/094313
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French (fr)
Chinese (zh)
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魏增斌
冯波
陶兴华
张盛武
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东莞新能源科技有限公司
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Priority to PCT/CN2016/094313 priority Critical patent/WO2018027652A1/en
Publication of WO2018027652A1 publication Critical patent/WO2018027652A1/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
    • H01M50/489—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
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • 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 invention belongs to the field of electrochemical energy storage technology, and more particularly to a method for preparing a diaphragm, a diaphragm and an electrochemical energy storage device using the same.
  • Lithium-ion batteries have been widely used in mobile phones and notebooks due to their high mass energy density and volumetric energy density, high operating voltage, wide operating temperature, long service life and environmental friendliness. On computers and various electric vehicles, even aerospace and wind energy solar energy storage devices are used.
  • a polyolefin material was generally used as the separator, and the separator was generally coated.
  • the common coating is ceramic coating, the main purpose is to improve the heat resistance of the separator to inhibit its heat shrinkage and avoid oxidation of the PE/PP separator.
  • the existing diaphragm bonding layers have large thicknesses and low bonding strength, and cannot meet the requirements for electrical performance and energy density of lithium ion batteries.
  • the object of the present invention is to provide a diaphragm which can ensure the adhesion between the pole piece and the diaphragm in the electrochemical energy storage device without adversely affecting the electrical performance of the electrochemical energy storage device, and provides the preparation of the above diaphragm.
  • the method and an electrochemical energy storage device using the separator are provided.
  • the present invention provides a separator comprising a porous substrate, a heat resistant coating applied to at least one side of the porous substrate, and a polymer bonding layer on the outermost layer, the polymer bonding layer coating Having a surface of the heat-resistant coating or a surface of the porous substrate not coated with the heat-resistant coating; the polymer bonding layer includes polymer particles, and the number of layers of the polymer particles in the polymer bonding layer is 4 or less
  • the layer preferably has two or more layers.
  • the coverage ratio of the polymer bonding layer to the porous substrate or the heat resistant coating layer is from 15 to 85%, preferably from 30 to 70%.
  • the polymer particles have a particle diameter of from 0.2 to 2 ⁇ m, preferably from 0.3 to 1 ⁇ m.
  • the polymer particles are homogeneous polymer microspheres or core-shell structured microspheres.
  • the degree of swelling of the polymer particles with respect to the electrolyte is from 20% to 1000%.
  • the outer shell of the core-shell microsphere is a polymer having high adhesion (adhesion to the negative electrode sheet of not less than 2 N/m), and the core is an affinity electrolyte (electrolyte) Polymer with a degree of swelling >100%).
  • the polymer particles are polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, styrene-butadiene copolymer, polyacrylonitrile, butadiene-acrylonitrile.
  • the polymer bonding layer further includes an auxiliary binder and a dispersing agent which are coated and bonded to the porous substrate or the heat resistant coating.
  • the material of the porous substrate is polyethylene, polypropylene, PET, cellulose or polyimide.
  • the heat resistant coating layer comprises a heat resistant material and the heat resistant material is adhered
  • the adhesive agent attached to the porous substrate is one or both of an inorganic ceramic material and a heat resistant polymer material.
  • the inorganic ceramic material is one or more of Al 2 O 3 , boehmite, SiO 2 , TiO 2 , MgO, ZnO, ZrO 2 , SnO 2 ;
  • the molecular material is one or more of polyimide and its derivatives, aromatic nylon and its modifications, phenolic resin, and polytetrafluoroethylene.
  • the heat-resistant coating adhesive is a polyvinyl alcohol, polyurethane, polyacrylic acid or polyacrylate adhesive.
  • the separator of the invention adopts a polymer bonding layer with a small number of polymer particle accumulation layers, which can improve the utilization efficiency and uniformity of the bonding layer, thereby improving the interfacial adhesion in the electrochemical energy storage device. At the same time, it can reduce the amount of polymer particles and effectively reduce the raw material cost of the separator. In addition, controlling the coverage area of the polymer bonding layer and the swelling degree of the polymer particles can ensure the density of the polymer bonding layer without affecting the ionic conductivity of the separator.
  • the present invention also provides a method of producing the separator of any of the above paragraphs, comprising the steps of:
  • the present invention effectively controls the particle bulk density and the number of layers of the polymer bonding layer by adjusting the viscosity and solid content of the polymer bonding layer.
  • the step 3) is carried out by screen printing or gravure coating to coat the polymer bonding layer. This is more advantageous for increasing the uniformity of the polymer bonding layer and reducing its thickness.
  • the step 3) adopts a multi-stage drying method when drying, and the temperature of each stage of the oven is set between 40 and 70 °C. This can reduce the movement of the polymer particles caused by the evaporation of the solvent during drying, and ensure the effect of the particle accumulation layer after the separator coating is dried.
  • the heat-resistant coating glue liquid comprises a heat-dissipating material having a uniform dispersion, a binder, and a dispersion solvent, and the viscosity is adjusted to 50 to 2000 mPas.
  • the thickness of the single-layer heat-resistant coating layer is 1-6 ⁇ m.
  • the present invention also provides an electrochemical energy storage device comprising a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive and negative electrode sheets, and an electrolyte; the separator is as described in any of the above paragraphs.
  • the diaphragm The diaphragm.
  • the invention realizes the thickness and electrical performance of the electrochemical energy storage device under the premise of ensuring the bonding between the pole piece and the diaphragm by designing the polymer bonding layer, thereby ensuring the The fabricated electrochemical energy storage device can maintain high hardness and good cycle characteristics.
  • Figure 1 is a schematic view showing an interlayer structure of the separator of the present invention.
  • FIG. 2 is a schematic view showing another interlayer structure of the separator of the present invention.
  • Fig. 3 is an electron micrograph of the separator of Example 1 of the present invention.
  • the separator of the present invention comprises a porous substrate 10, a heat resistant coating 20 coated on one or both sides of the porous substrate 10, and a polymeric bonding layer 30 on the outermost layer.
  • the polymer bonding layer 30 is coated on the surface of the heat resistant coating 20 or the surface of the porous substrate 10 to which the heat resistant coating 20 is not applied.
  • the polymer bonding layer 30 includes polymer particles which can be bonded when the pole piece is hot pressed.
  • the number of layers of the polymer particles in the polymer bonding layer is less than or equal to 4 layers, and preferably the number of stacked layers is less than or equal to 2.
  • Floor is preferably the number of stacked layers.
  • the polymer particles are homogeneous polymer microspheres or core-shell microspheres as shown in Figures 1-2.
  • the shell of the core-shell microspheres is a polymer with high adhesion, and the core is an affinity electrolyte or a compound that acts as a mechanically stable support.
  • the following examples and comparative examples not only use the same positive electrode sheet, negative electrode sheet, electrolyte solution and preparation process, but also the porous substrate and ceramic coating of the separator are also used in the same formulation. That is, the porous substrate is a 9 ⁇ m PE substrate, and the ceramic coating is a layer of alumina ceramic. It will be readily understood that in practical applications, both ceramic-coated ceramic particles and porous substrates may employ other materials that are listed or that do not contradict the description of the present invention.
  • the electrochemical energy storage device referred to in the present invention may include a common secondary battery or a primary battery such as a lithium ion battery, a sodium ion battery, a zinc ion battery, a capacitor, a lithium sulfur battery, or a sodium sulfur battery.
  • a lithium ion battery such as a lithium ion battery, a sodium ion battery, a zinc ion battery, a capacitor, a lithium sulfur battery, or a sodium sulfur battery.
  • the porous substrate was a 9 ⁇ m thick polypropylene film.
  • the composition of the heat-resistant coating glue is aluminum oxide ceramic, butadiene-styrene polymer, deionized water mass ratio of 35:10:55, preparation The process is: firstly add 30Kg of butadiene-styrene polymer and deionized water to a double planetary mixer with a volume of 60L, and disperse at 45 ° C for 3 hours; then add 16.1 Kg of alumina ceramic powder.
  • the mixture was dispersed at a high speed of 45 ° C for 2 hours; then, ball milling was carried out using a nano-mill for 1.5 hours, and the grinding medium used was spherical zirconia beads having a diameter of 6 ⁇ m to obtain a heat-resistant coating glue.
  • the raw material includes 5 parts by mass of polyvinylidene fluoride (PVDF) powder, 95 parts by mass of deionized water and a small amount of dispersing agent fluoroether surfactant (mass content ⁇ 1%)
  • PVDF polyvinylidene fluoride
  • the structure of polyvinylidene fluoride is a core-shell structure, the core of which is PVDF homopolymer, the outer shell is PVDF-HFP copolymer, the electrolyte swelling degree is 150%, the particle diameter is 0.6 ⁇ m;
  • the preparation process is: 47.5 Kg deionized water and 2.5 Kg of PVDF were added to a double planetary mixer, and a small amount of dispersant was added and mixed at 45 ° C for 1 hour to prepare a polymer adhesive coating glue having a solid content of about 5%.
  • Preparation of polymer bonding layer The porous substrate + heat-resistant coating obtained in 3) is surface-coated by screen printing to form a double-sided coating structure, and the quality and thickness of the two-sided coating are consistent.
  • the coating speed is 4m/min
  • the coating amount is controlled to be 0.03mg/cm 2
  • the drying is performed by three-stage drying, the length of each oven is 3m, and the set temperature of the oven is 50°C, 60°C, 60°C; After drying, the polymer bonding layer was deposited as 1-2 layers of particles on the heat resistant coating.
  • lithium cobaltate positive electrode active material
  • Super-P conductive agent superconducting carbon
  • PVDF adhesive Polyvinylidene fluoride
  • the above positive electrode sheet, separator and negative electrode sheet are wound into a battery core, and the separator is placed between the positive electrode sheet and the negative electrode sheet; the positive electrode is extracted by aluminum ear spot welding, and the negative electrode is extracted by nickel tab spot welding. Then, the battery is placed in an aluminum-plastic packaging bag, and the above electrolyte is injected, and a polymer lithium ion battery is prepared through a process of encapsulation, formation, and capacity.
  • the preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded.
  • the preparation of the layers that is to say the preparation of the separator, 4), 5) two steps:
  • polymer bonding layer glue is made of 25 parts by mass of core-shell polymer emulsion (solid content 30%), 40 parts by mass of deionized water and 35 parts by mass of ethanol
  • the preparation process is: first adding 50Kg of deionized water and ethanol solvent to the double planetary mixer, mixing at 25 ° C for 1 hour; then adding 16.7Kg of core-shell polymer dispersion, dispersing at 45 ° C 2 Hours, get Polymer bond coating glue.
  • the preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded.
  • the preparation of the layers that is to say the preparation of the separator, 4), 5) two steps:
  • the polymer particles of the polymer bonding layer in this embodiment are selected as styrene-butadiene copolymer, the total swelling degree is 130%, the particle diameter is 1.8 ⁇ m; the polymer
  • the bonding layer glue is prepared by dispersing 25 parts by mass of a styrene-butadiene copolymer dispersion (solid content 40%), 0.1 parts by mass of sodium carboxymethylcellulose, and 75 parts by mass of deionized water; Yes: 75Kg of deionized water and 0.1Kg of sodium carboxymethylcellulose were added to a dual planetary mixer and mixed at 45 ° C for 1 hour; then 25 kg of styrene-butadiene copolymer dispersion was added at 45 ° C. Dispersion for 2 hours gave a polymer bond coat.
  • the preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded.
  • the preparation of the layers that is to say the preparation of the separator, 4), 5) two steps:
  • polymer bonding layer glue The polymer particles of the polymer bonding layer in this embodiment are selected as acrylate-acrylic acid copolymer, the total swelling degree is 550%, the particle diameter is 0.2 ⁇ m; polymer bonding
  • the layering liquid is prepared by using 25 parts by mass of an acrylate-acrylic acid copolymer (solid content of 40%) and 75 parts by mass of deionized water; the preparation process is: adding 75 kg of deionized water and 25 kg of acrylate-acrylic acid copolymer to The mixture was mixed at 45 ° C for 2 hours in a double planetary mixer to obtain a polymer bond coat glue having a solid content of 10%.
  • the preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded.
  • the preparation of the layers that is to say the preparation of the separator, 4), 5) two steps:
  • the polymer particles of the polymer bonding layer are selected as polyacrylate particles, the total swelling degree is 930%, the particle diameter is 0.2 ⁇ m; the polymer bonding layer glue
  • the liquid was prepared in an amount of 25 parts by mass of a polyacrylate dispersion (solid content: 40%), 0.1 parts by mass of sodium carboxymethylcellulose, and 75 parts by mass of deionized water; the preparation process was: 75 Kg of deionized water and 0.1 Kg hydroxymethylcellulose sodium was added to a double planetary mixer and mixed at 45 ° C for 1 hour; then 25 kg of polyacrylate dispersion was added and dispersed at 45 ° C for 2 hours to obtain a polymer having a solid content of approximately 10%. Bonding coating glue.
  • the preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded.
  • the preparation of the layers that is to say the preparation of the separator, 4), 5) two steps:
  • the polymer particles of the polymer bonding layer are selected as core-shell polymer, the outer shell is acrylic-acrylate copolymer, and the inner core is acrylate-acrylonitrile polymerization.
  • the polymer bonding layer glue is prepared by 45 parts by mass of the core-shell structured particle dispersion (solid content 20%) and 55 parts by mass of deionized water; The procedure was as follows: 55 Kg of deionized water and 45 Kg of core-shell structured particle dispersion were added to a double planetary mixer and mixed at 45 ° C for 2 hours to obtain a polymer bond coat glue having a solid content of 9%.
  • the preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present comparative example is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded.
  • the preparation of the layers that is to say the preparation of the separator, 4), 5) two steps:
  • polymer bonding layer glue The polymer of the polymer bonding layer in the comparative example was selected as a polyvinylidene fluoride-hexafluoropropylene copolymer, the swelling degree was 190%, and the particle diameter was 1.5 ⁇ m; The process is: adding 68Kg of deionized water and 12Kg of PVDF-HFP to the double planetary mixer, adding a small amount of dispersant, mixing at 45 ° C for 6 hours, to prepare a polymer bond coat with a solid content of about 15%. Glue.
  • Preparation of polymer bonding layer The surface of the porous substrate + heat-resistant coating is coated by a rotary spray method to form a double-sided coating structure, and the quality and thickness of the double-sided coating are kept consistent; the coating speed is 8m/min, the coating amount is controlled to 0.13mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, the polymer
  • the adhesive layer is island-mounted and linearly distributed on the heat-resistant coating layer, wherein the island-like coating has an area of 1 ⁇ m to 10 mm and a height of 1 ⁇ m to 100 ⁇ m; the linear coating has a width of 1 ⁇ m to 1 mm and a length of 1 ⁇ m. -50 mm, height 1 ⁇ m - 100 ⁇ m.
  • the lithium ion battery and its separator produced in each of the examples and the comparative examples were subjected to the following methods. Can test, and the test results are listed in Table 2.
  • the particle morphology and the number of layers of the polymer bonding layer were detected by scanning electron microscopy (ZEISS Sigma/X-max).
  • the particle morphology can be determined by scanning the surface morphology of the separator.
  • the number of layers can pass through the ion beam.
  • Sectional grinding (CP) is used to make the diaphragm section, which is then determined by electron microscopy.
  • the particle size distribution can be detected by laser particle size analyzer (Mastersizer 3000).
  • the conductivity test of the diaphragm the diaphragm and two pieces of stainless steel sheet into a button battery, injected into the electrolyte, connected to the electrochemical workstation, test the AC impedance of the button battery, the frequency range is 1Hz ⁇ 50000Hz, sweep frequency 5Hz,
  • the analog circuit is R(CR), from which the AC impedance is fitted to calculate the conductivity of the diaphragm.
  • Interface adhesion test After the cell is discharged at a constant current of 1 C to 3.0 V, the cell is disassembled, and the positive electrode, the separator and the negative electrode are cut out by a blade with a length of 100 mm and a width of 10 mm. The double-sided tape was adhered to the stainless steel plate; the peeling force between the negative electrode sheet and the separator was tested by a 180-degree peeling force test method at a test speed of 300 mm/min and a test length of 40 mm.
  • a constant current is charged at a rate of 0.7 C to 4.35 V, and then charged at a constant voltage of 4.35 V until the current is 0.05 C, and then discharged at a constant current of 1 C to a voltage of 3.0 V, which is a charge and discharge cycle. Process; after repeating this charge and discharge cycle 500 times, the capacity retention ratio and the thickness expansion ratio were tested.
  • a constant current is charged at a rate of 0.7 C to a voltage of 4.35 V, and then charged at a constant voltage of 4.35 V until the current is 0.05 C, and then discharged at a constant current of 0.5 C and 2 C to a voltage of 3.0 V, respectively, and recorded. Discharge capacity at different magnifications.
  • the discharge capacity of the lithium ion battery discharge capacity of 2 C / discharge capacity of 0.5 C ⁇ 100%.
  • the polymer bonding layer improves the bonding, and also ensures the exposed area of the non-coating layer on the surface of the diaphragm, ensuring the normal conduction of lithium ions during charging and discharging, thereby not affecting the dynamic performance of the battery;
  • the polymer bonding layer ensures the interface bonding between the separator and the positive and negative electrodes. It is shown that the thickness expansion of the battery core after circulation is significantly smaller than that of the comparatively low adhesion force. The high interface bonding provided by the bonding layer effectively suppresses the deformation and expansion of the cell during use.
  • the thickness of the polymer bonding layer of the separator of the present invention is thin and uniform, so that the adhesion between the pole piece and the separator can be ensured without substantially increasing the thickness of the electrochemical energy storage device, and It will adversely affect the electrical performance of lithium-ion batteries.

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Abstract

Provided are a separator, a preparation method and an electrochemical energy storage device. The separator comprises a porous substrate (10), a heat-resistant coating (20) coated on at least one surface of the porous substrate and a polymer adhesive layer (30) located on the most superficial layer, wherein the polymer adhesive layer (30) is coated on the surface of the heat-resistant coating (20) or the surface of the porous substrate (10) not coated with the heat-resistant coating, and is characterized in that the polymer adhesive layer (30) comprises polymer particles, and the number of stack layers of the polymer particles in the polymer adhesive layer (30) is less than or equal to four, and preferably the number of stack layers is less than or equal to two. The separator not only can guarantee the adhesive strength between an electrode sheet and the separator in an electrochemical energy storage device, but also does not adversely affect the electrical performance of the electrochemical energy storage device.

Description

隔膜、制备方法及电化储能装置Diaphragm, preparation method and electrochemical energy storage device 技术领域Technical field
本发明属于电化储能技术领域，更具体地说，本发明涉及一种隔膜、隔膜的制备方法及使用此隔膜的电化储能装置。The invention belongs to the field of electrochemical energy storage technology, and more particularly to a method for preparing a diaphragm, a diaphragm and an electrochemical energy storage device using the same.
背景技术Background technique
锂离子电池由于具有较高的质量能量密度和体积能量密度、较高的工作电压、较宽的使用温度、较长的使用寿命、对环境友好等优点，已经被广泛地应用到移动电话、笔记本电脑以及各种电动汽车上，甚至用到了航空航天、风能太阳能储能设备上。Lithium-ion batteries have been widely used in mobile phones and notebooks due to their high mass energy density and volumetric energy density, high operating voltage, wide operating temperature, long service life and environmental friendliness. On computers and various electric vehicles, even aerospace and wind energy solar energy storage devices are used.
之前的锂离子电池中通常采用聚烯烃材料作为隔膜，且一般会对隔膜进行涂布处理。常见的涂布为陶瓷涂布，主要目的是提高隔膜的耐热性，以抑制其热收缩，并避免PE/PP材质隔膜被氧化。但是，随着锂离子电池能量密度的提升以及电芯硬度要求的提高，现在还经常需要在多孔基材或陶瓷层上涂覆粘接层，以保证电池极片与隔膜间的界面粘接，进而提高锂离子电池的循环性能，减小电芯的膨胀变形。In the prior lithium ion batteries, a polyolefin material was generally used as the separator, and the separator was generally coated. The common coating is ceramic coating, the main purpose is to improve the heat resistance of the separator to inhibit its heat shrinkage and avoid oxidation of the PE/PP separator. However, as the energy density of lithium-ion batteries increases and the hardness requirements of the cells increase, it is often necessary to apply a bonding layer on the porous substrate or ceramic layer to ensure the interface between the battery sheets and the separator. Further, the cycle performance of the lithium ion battery is improved, and the expansion deformation of the battery core is reduced.
但是，现有的隔膜粘接层都厚度较大且粘接力较低，无法满足锂离子电池对电性能及能量密度的要求。However, the existing diaphragm bonding layers have large thicknesses and low bonding strength, and cannot meet the requirements for electrical performance and energy density of lithium ion batteries.
有鉴于此，确有必要提供一种能够解决上述问题的隔膜。In view of this, it is indeed necessary to provide a diaphragm that can solve the above problems.
发明内容Summary of the invention
本发明的目的在于：提供一种既能保证电化学储能装置中极片与隔膜间的粘接力、又不会对电化储能装置电性能造成不良影响的隔膜，并提供上述隔膜的制备方法以及使用此隔膜的电化学储能装置。 The object of the present invention is to provide a diaphragm which can ensure the adhesion between the pole piece and the diaphragm in the electrochemical energy storage device without adversely affecting the electrical performance of the electrochemical energy storage device, and provides the preparation of the above diaphragm. The method and an electrochemical energy storage device using the separator.
为了实现上述发明目的，本发明提供了一种隔膜，其包括多孔基材、涂布在多孔基材至少一面的耐热涂层和位于最表层的聚合物粘接层，聚合物粘接层涂布在耐热涂层表面或未涂布耐热涂层的多孔基材表面；所述聚合物粘接层中包括聚合物颗粒，聚合物粘接层中聚合物颗粒的堆积层数小于等于4层，优选为堆积层数小于等于2层。In order to achieve the above object, the present invention provides a separator comprising a porous substrate, a heat resistant coating applied to at least one side of the porous substrate, and a polymer bonding layer on the outermost layer, the polymer bonding layer coating Having a surface of the heat-resistant coating or a surface of the porous substrate not coated with the heat-resistant coating; the polymer bonding layer includes polymer particles, and the number of layers of the polymer particles in the polymer bonding layer is 4 or less The layer preferably has two or more layers.
作为本发明隔膜的一种改进，所述聚合物粘接层对多孔基材或耐热涂层的覆盖面积比为15-85％，优选为30-70％。As a modification of the separator of the present invention, the coverage ratio of the polymer bonding layer to the porous substrate or the heat resistant coating layer is from 15 to 85%, preferably from 30 to 70%.
作为本发明隔膜的一种改进，所述聚合物颗粒的粒径为0.2-2μm，优选为0.3-1μm。As a modification of the separator of the present invention, the polymer particles have a particle diameter of from 0.2 to 2 μm, preferably from 0.3 to 1 μm.
作为本发明隔膜的一种改进，所述聚合物颗粒为均质聚合物微球，或是核壳结构微球。As a modification of the separator of the present invention, the polymer particles are homogeneous polymer microspheres or core-shell structured microspheres.
作为本发明隔膜的一种改进，所述聚合物颗粒相对于电解液的溶胀度为20％-1000％。As a modification of the separator of the present invention, the degree of swelling of the polymer particles with respect to the electrolyte is from 20% to 1000%.
作为本发明隔膜的一种改进，所述核壳结构微球的外壳为粘接力高(与负极片粘接力不低于2N/m)的聚合物，内核为亲和电解液(电解液溶胀度>100％)的聚合物。As an improvement of the separator of the present invention, the outer shell of the core-shell microsphere is a polymer having high adhesion (adhesion to the negative electrode sheet of not less than 2 N/m), and the core is an affinity electrolyte (electrolyte) Polymer with a degree of swelling >100%).
作为本发明隔膜的一种改进，所述聚合物颗粒为聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物、苯乙烯-丁二烯共聚物、聚丙烯腈、丁二烯-丙烯腈聚合物、聚丙烯酸、聚丙烯酸酯和丙烯酸酯-苯乙烯共合物中的一种，或者是以上聚合物的混合物，或是以上聚合物单体中的两种或更多种的共聚物。As a modification of the separator of the present invention, the polymer particles are polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, styrene-butadiene copolymer, polyacrylonitrile, butadiene-acrylonitrile. One of a polymer, a polyacrylic acid, a polyacrylate, and an acrylate-styrene complex, or a mixture of the above polymers, or a copolymer of two or more of the above polymer monomers.
作为本发明隔膜的一种改进，所述聚合物粘接层中还包括与多孔基材或耐热涂层进行涂布粘接的辅助粘接剂和分散剂。As an improvement of the separator of the present invention, the polymer bonding layer further includes an auxiliary binder and a dispersing agent which are coated and bonded to the porous substrate or the heat resistant coating.
作为本发明隔膜的一种改进，所述多孔基材的材料为聚乙烯、聚丙烯、PET、纤维素或聚酰亚胺。As an improvement of the separator of the present invention, the material of the porous substrate is polyethylene, polypropylene, PET, cellulose or polyimide.
作为本发明隔膜的一种改进，所述耐热涂层包括耐热材料和将耐热材料粘 接在多孔基材上的粘接剂，耐热材料为无机陶瓷材料、耐热高分子材料中的一种或两种。As an improvement of the separator of the present invention, the heat resistant coating layer comprises a heat resistant material and the heat resistant material is adhered The adhesive agent attached to the porous substrate is one or both of an inorganic ceramic material and a heat resistant polymer material.
作为本发明隔膜的一种改进，所述无机陶瓷材料为Al2O3、勃姆石、SiO2、TiO2、MgO、ZnO、ZrO2、SnO2中的一种或几种；耐热高分子材料为聚酰亚胺及其衍生物、芳香族尼龙及其改性物、酚醛树脂、聚四氟乙烯的一种或几种。As an improvement of the separator of the present invention, the inorganic ceramic material is one or more of Al 2 O 3 , boehmite, SiO 2 , TiO 2 , MgO, ZnO, ZrO 2 , SnO 2 ; The molecular material is one or more of polyimide and its derivatives, aromatic nylon and its modifications, phenolic resin, and polytetrafluoroethylene.
作为本发明隔膜的一种改进，所述耐热涂层的粘接剂为聚乙烯醇、聚氨酯、聚丙烯酸或聚丙烯酸酯类粘接剂。As an improvement of the separator of the present invention, the heat-resistant coating adhesive is a polyvinyl alcohol, polyurethane, polyacrylic acid or polyacrylate adhesive.
与现有技术相比，本发明隔膜采用聚合物颗粒堆积层数较少的聚合物粘接层，可提高粘接层的利用效率和均匀性，进而提高电化储能装置中的界面粘接作用，同时还能减少聚合物颗粒的用量，有效降低隔膜的原料成本。另外，控制聚合物粘接层的覆盖面积及聚合物颗粒的溶胀度，可在保证聚合物粘接层密度的同时，不影响隔膜的离子电导率。Compared with the prior art, the separator of the invention adopts a polymer bonding layer with a small number of polymer particle accumulation layers, which can improve the utilization efficiency and uniformity of the bonding layer, thereby improving the interfacial adhesion in the electrochemical energy storage device. At the same time, it can reduce the amount of polymer particles and effectively reduce the raw material cost of the separator. In addition, controlling the coverage area of the polymer bonding layer and the swelling degree of the polymer particles can ensure the density of the polymer bonding layer without affecting the ionic conductivity of the separator.
为了实现上述发明目的，本发明还提供了一种制备上述任一段落所述隔膜的方法，其包括以下步骤：In order to achieve the above objects, the present invention also provides a method of producing the separator of any of the above paragraphs, comprising the steps of:
1)制备耐热涂层胶液，并将其均匀涂布在多孔基材的单面或双面上，干燥后得到耐热涂层；1) preparing a heat-resistant coating glue, and uniformly coating it on one or both sides of the porous substrate, and drying to obtain a heat-resistant coating;
2)将聚合物颗粒在去离子水中分散均匀，得到粘度为50-1000mPas、固含量为1-15％的聚合物粘接层胶液；2) dispersing the polymer particles uniformly in deionized water to obtain a polymer bonding layer glue having a viscosity of 50-1000 mPas and a solid content of 1-15%;
3)将聚合物粘接层胶液涂布在耐热涂层表面或未涂布耐热涂层的多孔基材表面，干燥后得到聚合物颗粒堆积层数小于等于4层的聚合物粘接层。3) coating the polymer bonding layer glue on the surface of the heat-resistant coating or the surface of the porous substrate not coated with the heat-resistant coating, and drying to obtain polymer bonding with the number of layers of polymer particles being 4 or less. Floor.
与现有技术相比，本发明通过调节聚合物粘接层胶液的粘度和固含量，来有效控制聚合物粘接层的颗粒堆积密度和层数。Compared with the prior art, the present invention effectively controls the particle bulk density and the number of layers of the polymer bonding layer by adjusting the viscosity and solid content of the polymer bonding layer.
作为本发明隔膜的制备方法的一种改进，所述步骤3)采用丝网印刷或者凹版涂布进行聚合物粘接层胶液的涂布。这样更有利于提高聚合物粘接层的均匀性并降低其厚度。 As an improvement of the preparation method of the separator of the present invention, the step 3) is carried out by screen printing or gravure coating to coat the polymer bonding layer. This is more advantageous for increasing the uniformity of the polymer bonding layer and reducing its thickness.
作为本发明隔膜的制备方法的一种改进，所述步骤3)在干燥时采用多段烘干方式，每段烘箱的温度设定在40-70℃之间。这样做可以减少干燥时溶剂挥发导致的聚合物颗粒的运动，保证隔膜涂层干燥后的颗粒堆积层效果。As an improvement of the preparation method of the separator of the present invention, the step 3) adopts a multi-stage drying method when drying, and the temperature of each stage of the oven is set between 40 and 70 °C. This can reduce the movement of the polymer particles caused by the evaporation of the solvent during drying, and ensure the effect of the particle accumulation layer after the separator coating is dried.
作为本发明隔膜的制备方法的一种改进，所述耐热涂层胶液包括分散均匀的耐热材料、粘接剂和分散溶剂，粘度调节为50-2000mPas。As an improvement of the preparation method of the separator of the present invention, the heat-resistant coating glue liquid comprises a heat-dissipating material having a uniform dispersion, a binder, and a dispersion solvent, and the viscosity is adjusted to 50 to 2000 mPas.
作为本发明隔膜的制备方法的一种改进，所述涂布在多孔基材上的耐热涂层胶液干燥除去溶剂后，单层耐热涂层的厚度为1-6μm。As an improvement of the preparation method of the separator of the present invention, after the heat-resistant coating glue applied on the porous substrate is dried to remove the solvent, the thickness of the single-layer heat-resistant coating layer is 1-6 μm.
为了实现上述发明目的，本发明还提供了一种电化储能装置，其包括正极片、负极片、间隔于正负极片之间的隔膜以及电解液；所述隔膜为上述任一段落中所述的隔膜。In order to achieve the above object, the present invention also provides an electrochemical energy storage device comprising a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive and negative electrode sheets, and an electrolyte; the separator is as described in any of the above paragraphs. The diaphragm.
与现有技术相比，本发明通过对聚合物粘接层的设计，实现了在保证极片与隔膜界面粘接的前提下，不影响电化储能装置的厚度及电性能，因此，确保了所制作的电化储能装置可维持较高的硬度及良好的循环特性。Compared with the prior art, the invention realizes the thickness and electrical performance of the electrochemical energy storage device under the premise of ensuring the bonding between the pole piece and the diaphragm by designing the polymer bonding layer, thereby ensuring the The fabricated electrochemical energy storage device can maintain high hardness and good cycle characteristics.
附图说明DRAWINGS
下面结合附图和具体实施例，对本发明隔膜、制备方法、电化储能装置及其有益效果进行详细说明。The diaphragm, the preparation method, the electrochemical energy storage device and the beneficial effects thereof are described in detail below with reference to the accompanying drawings and specific embodiments.
图1为本发明隔膜的一种层间结构示意图。Figure 1 is a schematic view showing an interlayer structure of the separator of the present invention.
图2为本发明隔膜的另一种层间结构示意图。2 is a schematic view showing another interlayer structure of the separator of the present invention.
图3为本发明实施例1的隔膜的电镜照片。Fig. 3 is an electron micrograph of the separator of Example 1 of the present invention.
具体实施方式detailed description
为了使本发明的发明目的、技术方案和有益技术效果更加清晰，以下结合实施例和附图进一步详细描述本发明。但是，应当理解的是，本发明的实施例仅仅是为了解释本发明，并非为了限制本发明，且本发明的实施例并不局限于说明书中给出的实施例。实施例中未注明实验条件的按常规条件制作，或按材 料供应商推荐的条件制作。In order to make the objects, technical solutions, and advantageous effects of the present invention more clear, the present invention will be described in further detail below with reference to the embodiments and the accompanying drawings. However, it is to be understood that the embodiments of the present invention are not intended to limit the invention, and the embodiments of the present invention are not limited to the embodiments set forth in the specification. In the examples, the experimental conditions are not specified, and the materials are prepared according to the conventional conditions. The conditions recommended by the material supplier are produced.
请参阅图1和图2，本发明隔膜包括多孔基材10、涂布在多孔基材10一面或两面的耐热涂层20和位于最表层的聚合物粘接层30。聚合物粘接层30涂布在耐热涂层20表面或未涂布耐热涂层20的多孔基材10表面。聚合物粘接层30中包括与极片热压时可发生粘接作用的聚合物颗粒，聚合物粘接层中聚合物颗粒的堆积层数小于等于4层，优选为堆积层数小于等于2层。Referring to Figures 1 and 2, the separator of the present invention comprises a porous substrate 10, a heat resistant coating 20 coated on one or both sides of the porous substrate 10, and a polymeric bonding layer 30 on the outermost layer. The polymer bonding layer 30 is coated on the surface of the heat resistant coating 20 or the surface of the porous substrate 10 to which the heat resistant coating 20 is not applied. The polymer bonding layer 30 includes polymer particles which can be bonded when the pole piece is hot pressed. The number of layers of the polymer particles in the polymer bonding layer is less than or equal to 4 layers, and preferably the number of stacked layers is less than or equal to 2. Floor.
聚合物颗粒为均质聚合物微球，或是图1～2所示的核壳结构微球。核壳结构微球的外壳为粘接力高的聚合物，内核为亲和电解液或起机械稳定支撑作用的化合物。The polymer particles are homogeneous polymer microspheres or core-shell microspheres as shown in Figures 1-2. The shell of the core-shell microspheres is a polymer with high adhesion, and the core is an affinity electrolyte or a compound that acts as a mechanically stable support.
以下结合实施例说明本发明的有益效果。为了更便于粘接涂层性能参数的直观对比，以下实施例和对比例不仅采用相同的正极片、负极片、电解液以及制备工艺，而且隔膜的多孔基材和陶瓷涂层也都采用同一配方，即多孔基材都为9μm的PE基材，陶瓷涂层均为三氧化二铝陶瓷层。易于理解的是，在实际应用中，陶瓷涂层的陶瓷颗粒和多孔基材均可以采用其他已列出或与本发明的描述并不矛盾的常用材料。Advantageous effects of the present invention will be described below with reference to the embodiments. In order to facilitate the visual comparison of the performance parameters of the bonding coating, the following examples and comparative examples not only use the same positive electrode sheet, negative electrode sheet, electrolyte solution and preparation process, but also the porous substrate and ceramic coating of the separator are also used in the same formulation. That is, the porous substrate is a 9 μm PE substrate, and the ceramic coating is a layer of alumina ceramic. It will be readily understood that in practical applications, both ceramic-coated ceramic particles and porous substrates may employ other materials that are listed or that do not contradict the description of the present invention.
本发明所指的电化储能装置可以包含锂离子电池、钠离子电池、锌离子电池、电容器、锂硫电池、钠硫电池等常见的二次电池或一次电池。虽然以下实施例和对比例以锂离子电池为例进行说明，但应当理解的是，本发明的范围不仅限于此。The electrochemical energy storage device referred to in the present invention may include a common secondary battery or a primary battery such as a lithium ion battery, a sodium ion battery, a zinc ion battery, a capacitor, a lithium sulfur battery, or a sodium sulfur battery. Although the following examples and comparative examples are described by taking a lithium ion battery as an example, it should be understood that the scope of the invention is not limited thereto.
聚合物颗粒的溶胀度可以通过测试得到：将聚合物微球乳液倒入PTFE模具中，在60℃下真空干燥成膜后，裁切约5g的聚合物膜样块，使用天平准确测量重量后，浸入电解液中，85℃环境中静置6h后，取出样块，擦拭干净表面残留的电解液，再进行准确称重后，即可计算得到其在电解液中的溶胀度。溶胀度＝(高温静置6h后质量-初始样块质量)/初始样块质量×100％。 The degree of swelling of the polymer particles can be obtained by testing: the polymer microsphere emulsion is poured into a PTFE mold, and after vacuum drying at 60 ° C to form a film, about 5 g of the polymer film sample is cut, and the weight is accurately measured using a balance. After immersing in the electrolyte and letting it stand for 8 hours in an environment of 85 ° C, the sample is taken out, the electrolyte remaining on the surface is wiped off, and after accurate weighing, the degree of swelling in the electrolyte can be calculated. Swelling degree = (mass - initial mass after 6 h of standing at high temperature) / initial mass of the sample × 100%.
实施例1Example 1
隔膜的制备：Preparation of the diaphragm:
1)多孔基材采用9μm厚的聚丙烯薄膜。1) The porous substrate was a 9 μm thick polypropylene film.
2)耐热涂层胶液的制备：耐热涂层胶液的组分为三氧化二铝陶瓷、丁二烯-苯乙烯聚合物、去离子水的质量比为35:10:55，制备过程是：先将丁二烯-苯乙烯聚合物和去离子水共30Kg加入到容积为60L的双行星搅拌机中，在45℃下分散3小时；再将三氧化二铝陶瓷粉体16.1Kg加入到搅拌机中，在45℃下高速分散2小时；然后采用纳米研磨机进行球磨，时间为1.5小时，所采用的研磨介质为直径6μm的球形氧化锆珠，得到耐热涂层胶液。2) Preparation of heat-resistant coating glue: The composition of the heat-resistant coating glue is aluminum oxide ceramic, butadiene-styrene polymer, deionized water mass ratio of 35:10:55, preparation The process is: firstly add 30Kg of butadiene-styrene polymer and deionized water to a double planetary mixer with a volume of 60L, and disperse at 45 ° C for 3 hours; then add 16.1 Kg of alumina ceramic powder. In a mixer, the mixture was dispersed at a high speed of 45 ° C for 2 hours; then, ball milling was carried out using a nano-mill for 1.5 hours, and the grinding medium used was spherical zirconia beads having a diameter of 6 μm to obtain a heat-resistant coating glue.
3)耐热涂层的制备：采用转移涂布方式对多孔基材进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为6m/min，涂覆量控制为0.23mg/cm2，基材两面涂布厚度均为1μm；烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃。3) Preparation of heat-resistant coating: The surface of the porous substrate was coated by transfer coating to form a double-sided coating structure, and the quality and thickness of the two-side coating were consistent; the coating speed was 6 m/min, and the coating speed was 6 m/min. The coverage is controlled to 0.23 mg/cm 2 , the thickness of both sides of the substrate is 1 μm; the drying is performed by three-stage drying, the length of each oven is 3 m, and the set temperature of the oven is 50 ° C, 60 ° C, 60 ° C.
4)聚合物粘接层胶液的制备：原料包括5质量份的聚偏氟乙烯(PVDF)粉末、95质量份的去离子水以及少量分散剂氟醚类表面活性剂(质量含量<1％)；其中，聚偏氟乙烯的结构为核壳结构，其内核为PVDF均聚物、外壳为PVDF-HFP共聚物，电解液溶胀度150％，粒径为0.6μm；制备过程是：将47.5Kg去离子水和2.5Kg的PVDF加入到双行星搅拌机中，并加入少量分散剂，在45℃下混合1小时，配制得到固含量约为5％的聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: The raw material includes 5 parts by mass of polyvinylidene fluoride (PVDF) powder, 95 parts by mass of deionized water and a small amount of dispersing agent fluoroether surfactant (mass content <1%) Among them, the structure of polyvinylidene fluoride is a core-shell structure, the core of which is PVDF homopolymer, the outer shell is PVDF-HFP copolymer, the electrolyte swelling degree is 150%, the particle diameter is 0.6 μm; the preparation process is: 47.5 Kg deionized water and 2.5 Kg of PVDF were added to a double planetary mixer, and a small amount of dispersant was added and mixed at 45 ° C for 1 hour to prepare a polymer adhesive coating glue having a solid content of about 5%.
5)聚合物粘接层的制备：采用丝网印刷方式对3)得到的多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为4m/min，涂覆量控制为0.03mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后，聚合物粘接层在耐热涂层上呈1-2层颗粒堆积。5) Preparation of polymer bonding layer: The porous substrate + heat-resistant coating obtained in 3) is surface-coated by screen printing to form a double-sided coating structure, and the quality and thickness of the two-sided coating are consistent. The coating speed is 4m/min, the coating amount is controlled to be 0.03mg/cm 2 , the drying is performed by three-stage drying, the length of each oven is 3m, and the set temperature of the oven is 50°C, 60°C, 60°C; After drying, the polymer bonding layer was deposited as 1-2 layers of particles on the heat resistant coating.
正极片的制备：将钴酸锂(正极活性物质)、导电剂超导碳(Super-P)、粘接剂 聚偏氟乙烯(PVDF)按质量比96:2.0:2.0混合均匀，制成具有一定粘度的锂离子电池正极浆料；将浆料涂布在集流体铝箔上，在95℃下烘干后进行冷压；然后进行切边、裁片、分条，分条后在真空条件下85℃烘干4小时，之后焊接极耳，制成锂离子电池正极片。Preparation of positive electrode sheet: lithium cobaltate (positive electrode active material), conductive agent superconducting carbon (Super-P), adhesive Polyvinylidene fluoride (PVDF) is uniformly mixed at a mass ratio of 96:2.0:2.0 to prepare a lithium ion battery positive electrode slurry having a certain viscosity; the slurry is coated on a current collector aluminum foil and dried at 95 ° C. Cold pressing; then trimming, cutting, slitting, striping, drying at 85 ° C for 4 hours under vacuum conditions, and then welding the tabs to form a positive electrode of a lithium ion battery.
负极片的制备：将石墨与导电剂SP、稳定剂羧甲基纤维素钠(CMC)、粘接剂丁苯橡胶(SBR)按质量比96.5:1.0:1.0:1.5混合均匀制成浆料，涂布在集流体铜箔上，并在85℃下烘干；然后进行切边、裁片、分条，分条后在真空条件下110℃烘干4小时，再焊接极耳，制成锂离子电池负极片。Preparation of negative electrode sheet: graphite and conductive agent SP, stabilizer sodium carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR) are mixed at a mass ratio of 96.5:1.0:1.0:1.5 to form a slurry. Coating on the current collector copper foil and drying at 85 ° C; then trimming, cutting, striping, striping, drying under vacuum at 110 ° C for 4 hours, and then welding the ear to make lithium Ion battery negative electrode.
电解液的制备：将LiPF6与溶剂(碳酸亚乙酯:碳酸二乙酯:甲基乙基碳酸酯:亚乙烯基碳酸酯的质量比为8:85:5:2)以8:92的质量比配制而溶液，作为锂离子电池的电解液。Preparation of electrolyte: LiPF 6 and solvent (ethylene carbonate: diethyl carbonate: methyl ethyl carbonate: vinylidene carbonate mass ratio of 8:85:5:2) at 8:92 The mass ratio is prepared as a solution for the lithium ion battery.
锂离子电池的制备：将上述正极片、隔膜和负极片卷绕成电芯，且使隔膜位于正极片和负极片之间；正极以铝极耳点焊引出，负极以镍极耳点焊引出；然后将电芯置于铝塑包装袋中，注入上述电解液，经封装、化成、容量等工序，制成聚合物锂离子电池。Preparation of lithium ion battery: the above positive electrode sheet, separator and negative electrode sheet are wound into a battery core, and the separator is placed between the positive electrode sheet and the negative electrode sheet; the positive electrode is extracted by aluminum ear spot welding, and the negative electrode is extracted by nickel tab spot welding. Then, the battery is placed in an aluminum-plastic packaging bag, and the above electrolyte is injected, and a polymer lithium ion battery is prepared through a process of encapsulation, formation, and capacity.
实施例2Example 2
本实施例的多孔基材、耐热涂层、正极片、负极片、电解液、锂离子电池的制备工艺均与实施例1相同，区别仅在于聚合物粘接层胶液和聚合物粘接层的制备，也就是说隔膜的制备的第4)、5)两步：The preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded. The preparation of the layers, that is to say the preparation of the separator, 4), 5) two steps:
4)聚合物粘接层胶液的制备：本实施例中聚合物粘接层的聚合物颗粒选择为核壳结构，外壳为苯乙烯-丙烯酸酯共聚物，内核为丙烯酸酯聚合物，总溶胀度450％，粒径为0.45μm；聚合物粘接层胶液以25质量份的核壳结构聚合物乳液(固含量30％)、40质量份的去离子水和35质量份的乙醇制成；制备过程是：先将去离子水和乙醇溶剂共50Kg加入到双行星搅拌机中，在25℃下混合1小时；然后再加入16.7Kg的核壳结构聚合物分散液，在45℃下分散2小时，得到 聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: In the embodiment, the polymer particles of the polymer bonding layer are selected as a core-shell structure, the outer shell is a styrene-acrylate copolymer, the inner core is an acrylate polymer, and the total swelling 450%, particle size 0.45μm; polymer bonding layer glue is made of 25 parts by mass of core-shell polymer emulsion (solid content 30%), 40 parts by mass of deionized water and 35 parts by mass of ethanol The preparation process is: first adding 50Kg of deionized water and ethanol solvent to the double planetary mixer, mixing at 25 ° C for 1 hour; then adding 16.7Kg of core-shell polymer dispersion, dispersing at 45 ° C 2 Hours, get Polymer bond coating glue.
5)聚合物粘接层的制备：采用凹版辊涂方式对多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为6m/min，涂覆量控制为0.08mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后可得到单层颗粒堆积的聚合物粘接层。5) Preparation of polymer bonding layer: surface coating of porous substrate + heat-resistant coating by gravure roll coating method to form double-sided coating structure, the quality and thickness of both coatings are consistent; coating speed It is 6m/min, the coating amount is controlled to 0.08mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, it can be obtained A layer of polymer bonded to a single layer of particles.
实施例3Example 3
本实施例的多孔基材、耐热涂层、正极片、负极片、电解液、锂离子电池的制备工艺均与实施例1相同，区别仅在于聚合物粘接层胶液和聚合物粘接层的制备，也就是说隔膜的制备的第4)、5)两步：The preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded. The preparation of the layers, that is to say the preparation of the separator, 4), 5) two steps:
4)聚合物粘接层胶液的制备：本实施例中聚合物粘接层的聚合物颗粒选择为苯乙烯-丁二烯共聚物，总溶胀度130％，粒径为1.8μm；聚合物粘接层胶液以25质量份的苯乙烯-丁二烯共聚物分散液(固含量40％)、0.1质量份的羟甲基纤维素钠和75质量份的去离子水制成；制备过程是：将75Kg去离子水和0.1Kg羟甲基纤维素钠加入到双行星搅拌机中，在45℃下混合1小时；然后再加入25Kg苯乙烯-丁二烯共聚物分散液，在45℃下分散2小时，得到聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: The polymer particles of the polymer bonding layer in this embodiment are selected as styrene-butadiene copolymer, the total swelling degree is 130%, the particle diameter is 1.8 μm; the polymer The bonding layer glue is prepared by dispersing 25 parts by mass of a styrene-butadiene copolymer dispersion (solid content 40%), 0.1 parts by mass of sodium carboxymethylcellulose, and 75 parts by mass of deionized water; Yes: 75Kg of deionized water and 0.1Kg of sodium carboxymethylcellulose were added to a dual planetary mixer and mixed at 45 ° C for 1 hour; then 25 kg of styrene-butadiene copolymer dispersion was added at 45 ° C. Dispersion for 2 hours gave a polymer bond coat.
5)聚合物粘接层的制备：采用丝网印刷方式对多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为6m/min，涂覆量控制为0.06mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后可得到单层颗粒堆积的聚合物粘接层。5) Preparation of polymer bonding layer: surface coating of porous substrate + heat-resistant coating by screen printing to form double-sided coating structure, the quality and thickness of both coatings are consistent; coating speed It is 6m/min, the coating amount is controlled to 0.06mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, it can be obtained A layer of polymer bonded to a single layer of particles.
实施例4Example 4
本实施例的多孔基材、耐热涂层、正极片、负极片、电解液、锂离子电池的制备工艺均与实施例1相同，区别仅在于聚合物粘接层胶液和聚合物粘接层的制备，也就是说隔膜的制备的第4)、5)两步： The preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded. The preparation of the layers, that is to say the preparation of the separator, 4), 5) two steps:
4)聚合物粘接层胶液的制备：本实施例中聚合物粘接层的聚合物颗粒选择为丙烯酸酯-丙烯酸共聚物，总溶胀度550％，粒径为0.2μm；聚合物粘接层胶液以25质量份的丙烯酸酯-丙烯酸共聚物(固含量40％)和75质量份的去离子水制成；制备过程是：将75Kg去离子水和25Kg丙烯酸酯-丙烯酸共聚物加入到双行星搅拌机中，在45℃下混合2小时，得到固含量为10％的聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: The polymer particles of the polymer bonding layer in this embodiment are selected as acrylate-acrylic acid copolymer, the total swelling degree is 550%, the particle diameter is 0.2 μm; polymer bonding The layering liquid is prepared by using 25 parts by mass of an acrylate-acrylic acid copolymer (solid content of 40%) and 75 parts by mass of deionized water; the preparation process is: adding 75 kg of deionized water and 25 kg of acrylate-acrylic acid copolymer to The mixture was mixed at 45 ° C for 2 hours in a double planetary mixer to obtain a polymer bond coat glue having a solid content of 10%.
5)聚合物粘接层的制备：采用丝网印刷方式对多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为6m/min，涂覆量控制为0.1mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后可得到1-2层颗粒堆积的聚合物粘接层。5) Preparation of polymer bonding layer: surface coating of porous substrate + heat-resistant coating by screen printing to form double-sided coating structure, the quality and thickness of both coatings are consistent; coating speed It is 6m/min, the coating amount is controlled to 0.1mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, it can be obtained A polymer bonding layer of 1-2 layers of particles.
实施例5Example 5
本实施例的多孔基材、耐热涂层、正极片、负极片、电解液、锂离子电池的制备工艺均与实施例1相同，区别仅在于聚合物粘接层胶液和聚合物粘接层的制备，也就是说隔膜的制备的第4)、5)两步：The preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded. The preparation of the layers, that is to say the preparation of the separator, 4), 5) two steps:
4)聚合物粘接层胶液的制备：本实施例中聚合物粘接层的聚合物颗粒选择为聚丙烯酸酯微粒，总溶胀度930％，粒径为0.2μm；聚合物粘接层胶液以25质量份的聚丙烯酸酯分散液(固含量40％)、0.1质量份的羟甲基纤维素钠和75质量份的去离子水制成；制备过程是：将75Kg去离子水和0.1Kg羟甲基纤维素钠加入到双行星搅拌机中，在45℃下混合1小时；然后再加入25Kg聚丙烯酸酯分散液，在45℃下分散2小时，得到固含量大致为10％的聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: In the embodiment, the polymer particles of the polymer bonding layer are selected as polyacrylate particles, the total swelling degree is 930%, the particle diameter is 0.2 μm; the polymer bonding layer glue The liquid was prepared in an amount of 25 parts by mass of a polyacrylate dispersion (solid content: 40%), 0.1 parts by mass of sodium carboxymethylcellulose, and 75 parts by mass of deionized water; the preparation process was: 75 Kg of deionized water and 0.1 Kg hydroxymethylcellulose sodium was added to a double planetary mixer and mixed at 45 ° C for 1 hour; then 25 kg of polyacrylate dispersion was added and dispersed at 45 ° C for 2 hours to obtain a polymer having a solid content of approximately 10%. Bonding coating glue.
5)聚合物粘接层的制备：采用凹版辊涂方式对多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为6m/min，涂覆量控制为0.12mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后可得到单层颗粒堆积的聚合物粘接层。 5) Preparation of polymer bonding layer: surface coating of porous substrate + heat-resistant coating by gravure roll coating method to form double-sided coating structure, the quality and thickness of both coatings are consistent; coating speed It is 6m/min, the coating amount is controlled to 0.12mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, it can be obtained A layer of polymer bonded to a single layer of particles.
实施例6Example 6
本实施例的多孔基材、耐热涂层、正极片、负极片、电解液、锂离子电池的制备工艺均与实施例1相同，区别仅在于聚合物粘接层胶液和聚合物粘接层的制备，也就是说隔膜的制备的第4)、5)两步：The preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present embodiment is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded. The preparation of the layers, that is to say the preparation of the separator, 4), 5) two steps:
4)聚合物粘接层胶液的制备：本实施例中聚合物粘接层的聚合物颗粒选择为核壳结构聚合物，外壳为丙烯酸-丙烯酸酯共聚物，内核为丙烯酸酯-丙烯腈聚合物，总溶胀度320％，粒径为0.4μm；聚合物粘接层胶液以45质量份的核壳结构颗粒分散液(固含量20％)和55质量份的去离子水制成；制备过程是：将55Kg去离子水和45Kg核壳结构颗粒分散液加入到双行星搅拌机中，在45℃下混合2小时，得到固含量为9％的聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: In the present embodiment, the polymer particles of the polymer bonding layer are selected as core-shell polymer, the outer shell is acrylic-acrylate copolymer, and the inner core is acrylate-acrylonitrile polymerization. , the total swelling degree is 320%, the particle diameter is 0.4 μm; the polymer bonding layer glue is prepared by 45 parts by mass of the core-shell structured particle dispersion (solid content 20%) and 55 parts by mass of deionized water; The procedure was as follows: 55 Kg of deionized water and 45 Kg of core-shell structured particle dispersion were added to a double planetary mixer and mixed at 45 ° C for 2 hours to obtain a polymer bond coat glue having a solid content of 9%.
5)聚合物粘接层的制备：采用凹版辊涂方式对多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为6m/min，涂覆量控制为0.16mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后可得到3-4层颗粒堆积的聚合物粘接层。5) Preparation of polymer bonding layer: surface coating of porous substrate + heat-resistant coating by gravure roll coating method to form double-sided coating structure, the quality and thickness of both coatings are consistent; coating speed It is 6m/min, the coating amount is controlled to 0.16mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, it can be obtained A 3-4 layer of polymer deposited layer of particles.
对比例1Comparative example 1
本对比例的多孔基材、耐热涂层、正极片、负极片、电解液、锂离子电池的制备工艺均与实施例1相同，区别仅在于聚合物粘接层胶液和聚合物粘接层的制备，也就是说隔膜的制备的第4)、5)两步：The preparation process of the porous substrate, the heat resistant coating, the positive electrode sheet, the negative electrode sheet, the electrolyte, and the lithium ion battery of the present comparative example is the same as that of the first embodiment except that the polymer bonding layer glue and the polymer are bonded. The preparation of the layers, that is to say the preparation of the separator, 4), 5) two steps:
4)聚合物粘接层胶液的制备：本对比例中聚合物粘接层的聚合物选择为聚偏氟乙烯-六氟丙烯共聚物，溶胀度为190％，粒径为1.5μm；制备过程是：将68Kg去离子水和12Kg的PVDF-HFP加入到双行星搅拌机中，并加入少量分散剂，在45℃下混合6小时，配制得到固含量约为15％的聚合物粘接涂层胶液。4) Preparation of polymer bonding layer glue: The polymer of the polymer bonding layer in the comparative example was selected as a polyvinylidene fluoride-hexafluoropropylene copolymer, the swelling degree was 190%, and the particle diameter was 1.5 μm; The process is: adding 68Kg of deionized water and 12Kg of PVDF-HFP to the double planetary mixer, adding a small amount of dispersant, mixing at 45 ° C for 6 hours, to prepare a polymer bond coat with a solid content of about 15%. Glue.
5)聚合物粘接层的制备：采用旋转喷雾方式对多孔基材+耐热涂层进行表面涂布，形成双面涂层结构，两面涂层的质量和厚度均保持一致；涂布速度为 8m/min，涂覆量控制为0.13mg/cm2，烘干采用三段烘干，每段烘箱长度为3m，烘箱的设定温度为50℃、60℃、60℃；干燥后，聚合物粘接层在耐热涂层上呈岛装和线状分布，其中，岛状涂层的面积为1μm-10mm，高度为1μm-100μm；线状涂层的宽度为1μm-1mm，长度为1μm-50mm，高度为1μm-100μm。5) Preparation of polymer bonding layer: The surface of the porous substrate + heat-resistant coating is coated by a rotary spray method to form a double-sided coating structure, and the quality and thickness of the double-sided coating are kept consistent; the coating speed is 8m/min, the coating amount is controlled to 0.13mg/cm 2 , the drying is carried out in three stages, the length of each oven is 3m, the set temperature of the oven is 50°C, 60°C, 60°C; after drying, the polymer The adhesive layer is island-mounted and linearly distributed on the heat-resistant coating layer, wherein the island-like coating has an area of 1 μm to 10 mm and a height of 1 μm to 100 μm; the linear coating has a width of 1 μm to 1 mm and a length of 1 μm. -50 mm, height 1 μm - 100 μm.
表1、各实施例及对比例的聚合物粘接层制备参数Table 1, preparation examples of various examples and comparative examples of polymer bonding layers
Figure PCTCN2016094313-appb-000001
Figure PCTCN2016094313-appb-000001
各实施例和对比例制得的锂离子电池及其隔膜的性能测试Performance test of lithium ion battery and its separator prepared in each of the examples and comparative examples
通过以下方法对各实施例和对比例中的制得的锂离子电池及其隔膜进行性 能测试，并将测试结果列于表2。The lithium ion battery and its separator produced in each of the examples and the comparative examples were subjected to the following methods. Can test, and the test results are listed in Table 2.
1、聚合物颗粒形貌及粒径测试：1. Polymer particle morphology and particle size test:
通过扫描电镜(ZEISS Sigma/X-max)对聚合物粘接层的颗粒形貌及堆积层数进行检测，检测颗粒形貌可通过扫描隔膜的表面形貌进行确定，堆积层数可通过离子束剖面研磨(CP)制作隔膜截面，后进行电镜扫描测试确定；粒径分布可通过激光粒度仪(Mastersizer3000)进行检测。The particle morphology and the number of layers of the polymer bonding layer were detected by scanning electron microscopy (ZEISS Sigma/X-max). The particle morphology can be determined by scanning the surface morphology of the separator. The number of layers can pass through the ion beam. Sectional grinding (CP) is used to make the diaphragm section, which is then determined by electron microscopy. The particle size distribution can be detected by laser particle size analyzer (Mastersizer 3000).
2、聚合物粘接层覆盖比例：2. Polymer bonding layer coverage ratio:
通过反射型红外光谱仪(Nicolet iS10)表征涂覆前后多孔基材特征峰的积分面积比值，可得出覆盖比例。覆盖比例＝聚合物粘接层涂覆后的多孔基材特征峰面积/涂覆前的多孔基材特征峰面积×100％The coverage ratio was obtained by reflecting the integral area ratio of the characteristic peaks of the porous substrate before and after coating by a reflective infrared spectrometer (Nicolet iS10). Coverage ratio = characteristic peak area of porous substrate after coating of polymer bonding layer / characteristic peak area of porous substrate before coating × 100%
3、隔膜的电化学稳定性测试：将隔膜与两片不锈钢片组成扣式电池，注入电解液，接入电化学工作站(AmetekVersaSTAT 4)，在0V～5V的电压范围内，施加0.05mV/s的扰动，从CV图中，观察是否有氧化还原峰，来确定隔膜的电化学稳定性。3, the electrochemical stability test of the diaphragm: the diaphragm and two pieces of stainless steel sheet into a button battery, injected into the electrolyte, connected to the electrochemical workstation (AmetekVersaSTAT 4), in the voltage range of 0V ~ 5V, apply 0.05mV / s The perturbation, from the CV diagram, to see if there is a redox peak to determine the electrochemical stability of the membrane.
4、隔膜的电导率测试：将隔膜与两片不锈钢片组成扣式电池，注入电解液，接入电化学工作站，测试该扣式电池的交流阻抗，频率范围为1Hz～50000Hz，扫频5Hz，模拟电路是R(CR)，由其拟合出的交流阻抗可以计算出隔膜的电导率的大小。4, the conductivity test of the diaphragm: the diaphragm and two pieces of stainless steel sheet into a button battery, injected into the electrolyte, connected to the electrochemical workstation, test the AC impedance of the button battery, the frequency range is 1Hz ~ 50000Hz, sweep frequency 5Hz, The analog circuit is R(CR), from which the AC impedance is fitted to calculate the conductivity of the diaphragm.
5、界面粘接力测试：将电芯以1C倍率恒流放电至3.0V电压后，拆开电芯，将正极片、隔膜及负极片整体用刀片裁出长100mm、宽10mm的长方形，用双面胶将其粘在不锈钢板上；采用180度剥离力测试方法测试负极片与隔膜间的剥离力，测试速度为300mm/min，测试长度为40mm。5. Interface adhesion test: After the cell is discharged at a constant current of 1 C to 3.0 V, the cell is disassembled, and the positive electrode, the separator and the negative electrode are cut out by a blade with a length of 100 mm and a width of 10 mm. The double-sided tape was adhered to the stainless steel plate; the peeling force between the negative electrode sheet and the separator was tested by a 180-degree peeling force test method at a test speed of 300 mm/min and a test length of 40 mm.
6、锂离子电池的循环性能测试：6. Cyclic performance test of lithium ion battery:
在25℃下，以0.7C倍率恒流充电至电压为4.35V，之后以4.35V恒压充电至电流为0.05C，然后以1C倍率恒流放电至电压为3.0V，此为一个充放电循环 过程；反复500次这种充放电循环后，测试容量保持率和厚度膨胀率。At 25 ° C, a constant current is charged at a rate of 0.7 C to 4.35 V, and then charged at a constant voltage of 4.35 V until the current is 0.05 C, and then discharged at a constant current of 1 C to a voltage of 3.0 V, which is a charge and discharge cycle. Process; after repeating this charge and discharge cycle 500 times, the capacity retention ratio and the thickness expansion ratio were tested.
500次循环后的容量保持率＝第500次循环后的放电容量/第一次循环后的放电容量×100％；500次循环后的厚度膨胀率＝第500次循环后的电芯厚度/第一次循环时的电芯厚度×100％。Capacity retention after 500 cycles = discharge capacity after the 500th cycle / discharge capacity after the first cycle × 100%; thickness expansion after 500 cycles = cell thickness after the 500th cycle / The thickness of the cell at the time of one cycle × 100%.
7、锂离子电池的倍率性能测试：7, lithium-ion battery rate performance test:
在25℃下，以0.7C倍率恒流充电至电压为4.35V，之后以4.35V恒压充电至电流为0.05C，然后分别以0.5C和2C的倍率恒流放电至电压为3.0V，记录不同倍率下的放电容量。At 25 ° C, a constant current is charged at a rate of 0.7 C to a voltage of 4.35 V, and then charged at a constant voltage of 4.35 V until the current is 0.05 C, and then discharged at a constant current of 0.5 C and 2 C to a voltage of 3.0 V, respectively, and recorded. Discharge capacity at different magnifications.
锂离子电池的放电倍率＝2C的放电容量/0.5C的放电容量×100％。The discharge capacity of the lithium ion battery = discharge capacity of 2 C / discharge capacity of 0.5 C × 100%.
表2、各实施例及对比例的锂离子电池测试结果Table 2, each example and comparative examples of lithium ion battery test results
Figure PCTCN2016094313-appb-000002
Figure PCTCN2016094313-appb-000002
从表2的测试结果可以看出：From the test results in Table 2, it can be seen that:
1)本发明隔膜与负极的粘接力虽然会随着覆盖面积、颗粒尺寸、聚合物种类有所变化，但是却都比常规采用PVDF喷涂制造的涂层粘接力更高； 1) Although the adhesion between the separator and the negative electrode of the present invention varies with the coverage area, particle size, and polymer type, it is more adhesive than the conventional PVDF spray coating;
2)聚合物粘接层中聚合物颗粒的堆积层数为1-2层的时候，既保证了涂层的均匀性，并且涂覆后对隔膜厚度的增加量很小，基本不会额外增加电芯的厚度；2) When the number of layers of polymer particles in the polymer bonding layer is 1-2 layers, the uniformity of the coating is ensured, and the increase in the thickness of the separator after coating is small, and the amount is not increased. The thickness of the cell;
3)聚合物粘接层在提高粘接的同时，还保证了隔膜表面非涂覆层的裸露面积，保证了充放电过程中锂离子的正常传导，从而不会影响电池的动力学性能；3) The polymer bonding layer improves the bonding, and also ensures the exposed area of the non-coating layer on the surface of the diaphragm, ensuring the normal conduction of lithium ions during charging and discharging, thereby not affecting the dynamic performance of the battery;
4)聚合物粘接层保证了隔膜与正负极之间的界面粘接，表现在循环后电芯的厚度膨胀明显比对比例的粘接力较低的隔膜要小，可见，聚合物粘接层所提供的高界面粘接有效抑制了电芯在使用过程中的变形与膨胀。4) The polymer bonding layer ensures the interface bonding between the separator and the positive and negative electrodes. It is shown that the thickness expansion of the battery core after circulation is significantly smaller than that of the comparatively low adhesion force. The high interface bonding provided by the bonding layer effectively suppresses the deformation and expansion of the cell during use.
综上所述，本发明隔膜的聚合物粘接层厚度薄且均匀，因此能够在基本不增加电化学储能装置的厚度的情况下，保证极片与隔膜间的粘接力，而且还不会对锂离子电池的电性能造成不良影响。In summary, the thickness of the polymer bonding layer of the separator of the present invention is thin and uniform, so that the adhesion between the pole piece and the separator can be ensured without substantially increasing the thickness of the electrochemical energy storage device, and It will adversely affect the electrical performance of lithium-ion batteries.
根据上述说明书的揭示和教导，本发明所属领域的技术人员还可以对上述实施方式进行适当的变更和修改。因此，本发明并不局限于上面揭示和描述的具体实施方式，对本发明的一些修改和变更也应当落入本发明的权利要求的保护范围内。此外，尽管本说明书中使用了一些特定的术语，但这些术语只是为了方便说明，并不对本发明构成任何限制。 The above embodiments may be modified and modified as appropriate by those skilled in the art in light of the above disclosure. Therefore, the invention is not limited to the specific embodiments disclosed and described herein, and the modifications and variations of the invention are intended to fall within the scope of the appended claims. In addition, although specific terms are used in the specification, these terms are merely for convenience of description and do not limit the invention.

Claims (10)

  1. 一种隔膜，包括多孔基材、涂布在多孔基材至少一面的耐热涂层和位于最表层的聚合物粘接层，聚合物粘接层涂布在耐热涂层表面或未涂布耐热涂层的多孔基材表面；其特征在于：所述聚合物粘接层中包括聚合物颗粒，聚合物粘接层中聚合物颗粒的堆积层数小于等于4层，优选为堆积层数小于等于2层。A separator comprising a porous substrate, a heat resistant coating applied to at least one side of the porous substrate, and a polymeric bonding layer on the outermost layer, the polymeric bonding layer being coated on the surface of the heat resistant coating or uncoated a porous substrate surface of the heat-resistant coating; characterized in that the polymer bonding layer comprises polymer particles, and the number of stacked layers of the polymer particles in the polymer bonding layer is less than or equal to 4 layers, preferably the number of stacked layers Less than or equal to 2 layers.
  2. 根据权利要求1所述的隔膜，其特征在于：所述聚合物粘接层对多孔基材或耐热涂层的覆盖面积比为15-85％，优选为30-70％。The separator according to claim 1, wherein the polymer bonding layer has a coverage area ratio of the porous substrate or the heat-resistant coating layer of from 15 to 85%, preferably from 30 to 70%.
  3. 根据权利要求1所述的隔膜，其特征在于：所述聚合物颗粒的粒径为0.2-2μm，优选为0.3-1μm。The separator according to claim 1, wherein the polymer particles have a particle diameter of from 0.2 to 2 μm, preferably from 0.3 to 1 μm.
  4. 根据权利要求1所述的隔膜，其特征在于：所述聚合物颗粒为均质聚合物微球，或是核壳结构微球。The separator according to claim 1, wherein said polymer particles are homogeneous polymer microspheres or core-shell structured microspheres.
  5. 根据权利要求4所述的隔膜，其特征在于：所述聚合物颗粒相对于电解液的溶胀度为20％-1000％。The separator according to claim 4, wherein the polymer particles have a degree of swelling relative to the electrolyte of from 20% to 1000%.
  6. 根据权利要求4所述的隔膜，其特征在于：所述核壳结构微球的外壳为与负极片粘接力不低于2N/m的聚合物，内核为电解液溶胀度>100％的聚合物。The separator according to claim 4, wherein the outer shell of the core-shell microspheres is a polymer having a bonding strength to the negative electrode sheet of not less than 2 N/m, and the core is a polymerization degree of the electrolyte having a swelling degree of >100%. Things.
  7. 根据权利要求5所述的隔膜，其特征在于：所述聚合物颗粒为聚偏氟乙烯、聚偏氟乙烯-六氟丙烯共聚物、苯乙烯-丁二烯共聚物、聚丙烯腈、丁二烯-丙烯腈聚合物、聚丙烯酸、聚丙烯酸酯和丙烯酸酯-苯乙烯共合物中的一种，或者是以上聚合物的混合物，或是以上聚合物单体中的两种或更多种的共聚物。The separator according to claim 5, wherein said polymer particles are polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, styrene-butadiene copolymer, polyacrylonitrile, and dibutyl One of an ene-acrylonitrile polymer, a polyacrylic acid, a polyacrylate, and an acrylate-styrene complex, or a mixture of the above polymers, or two or more of the above polymer monomers Copolymer.
  8. 一种权利要求1-7中任一项所述的隔膜的制备方法，其特征在于包括以下步骤：A method of preparing a separator according to any one of claims 1 to 7, comprising the steps of:
    1)制备耐热涂层胶液，并将其均匀涂布在多孔基材的单面或双面上，干燥后得到耐热涂层；1) preparing a heat-resistant coating glue, and uniformly coating it on one or both sides of the porous substrate, and drying to obtain a heat-resistant coating;
    2)将聚合物颗粒在去离子水中分散均匀，得到粘度为50-1000mPas、固含 量为1-15％的聚合物粘接层胶液；2) Disperse the polymer particles uniformly in deionized water to obtain a viscosity of 50-1000 mPas, solid content a polymer bonding layer glue of 1-15%;
    3)将聚合物粘接层胶液涂布在耐热涂层表面或未涂布耐热涂层的多孔基材表面，干燥后得到聚合物颗粒堆积层数小于等于4层的聚合物粘接层。3) coating the polymer bonding layer glue on the surface of the heat-resistant coating or the surface of the porous substrate not coated with the heat-resistant coating, and drying to obtain polymer bonding with the number of layers of polymer particles being 4 or less. Floor.
  9. 根据权利要求8所述的隔膜的制备方法，所述步骤3)采用丝网印刷或者凹版涂布进行聚合物粘接层胶液的涂布。The method for preparing a separator according to claim 8, wherein the step (3) is performed by screen printing or gravure coating to coat the polymer bonding layer.
  10. 一种电化储能装置，其包括正极片、负极片、间隔于正负极片之间的隔膜以及电解液，其特征在于：所述隔膜为权利要求1-7所述的隔膜。 An electrochemical energy storage device comprising a positive electrode sheet, a negative electrode sheet, a separator spaced between the positive and negative electrode sheets, and an electrolyte, wherein the separator is the separator according to claims 1-7.
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Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110707264A (en) * 2019-09-19 2020-01-17 河北金力新能源科技股份有限公司 High-conductivity coating diaphragm for lithium-sulfur battery and preparation method and application thereof
CN112054150A (en) * 2019-06-07 2020-12-08 三星Sdi株式会社 Separator for rechargeable lithium battery and rechargeable lithium battery including the same
US20200407543A1 (en) * 2018-03-02 2020-12-31 Arkema Inc. Fluoropolymer dispersion for separator coating
CN112670672A (en) * 2020-12-28 2021-04-16 横店集团东磁股份有限公司 Diaphragm for high-temperature storage, preparation method thereof and lithium ion battery
CN113054324A (en) * 2021-04-21 2021-06-29 上海恩捷新材料科技有限公司 High-safety diaphragm and battery
CN113795975A (en) * 2020-03-31 2021-12-14 宁德新能源科技有限公司 Separator, electrode assembly, battery, and electronic device
CN114024098A (en) * 2021-10-25 2022-02-08 珠海冠宇电池股份有限公司 Battery with a battery cell
CN114144932A (en) * 2021-03-31 2022-03-04 宁德新能源科技有限公司 Isolating membrane, electrochemical device comprising same and electronic device
US11539101B2 (en) * 2017-05-12 2022-12-27 Panasonic Holdings Corporation Nonaqueous electrolyte secondary battery
CN115836437A (en) * 2020-03-18 2023-03-21 宁德新能源科技有限公司 Electrochemical device and electronic device comprising same
CN116093538A (en) * 2023-04-06 2023-05-09 宁德新能源科技有限公司 Electrode assembly, electrochemical device, and electronic device
US11843272B2 (en) 2020-03-19 2023-12-12 Ningde Amperex Technology Limited Electronic device and method for improving battery cycling performance

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1340868A (en) * 2000-08-30 2002-03-20 住友化学工业株式会社 Diaphragm for anhydrous dielectric secondary cell and the anhydrous dielectric secondary cell
CN102610773A (en) * 2012-03-06 2012-07-25 宁德新能源科技有限公司 Polymer lithium ion battery and diaphragm thereof
WO2013141140A1 (en) * 2012-03-22 2013-09-26 日本ゼオン株式会社 Porous film for secondary batteries, method for producing same, electrode for secondary batteries, separator for secondary batteries, and secondary battery
CN104157811A (en) * 2013-12-11 2014-11-19 中航锂电（洛阳）有限公司 Lithium ion battery composite diaphragm and preparation method and application thereof
CN105324868A (en) * 2013-07-10 2016-02-10 日本瑞翁株式会社 Adhesive for lithium ion secondary batteries, separator for lithium ion secondary batteries, and lithium ion secondary battery

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1340868A (en) * 2000-08-30 2002-03-20 住友化学工业株式会社 Diaphragm for anhydrous dielectric secondary cell and the anhydrous dielectric secondary cell
CN102610773A (en) * 2012-03-06 2012-07-25 宁德新能源科技有限公司 Polymer lithium ion battery and diaphragm thereof
WO2013141140A1 (en) * 2012-03-22 2013-09-26 日本ゼオン株式会社 Porous film for secondary batteries, method for producing same, electrode for secondary batteries, separator for secondary batteries, and secondary battery
CN105324868A (en) * 2013-07-10 2016-02-10 日本瑞翁株式会社 Adhesive for lithium ion secondary batteries, separator for lithium ion secondary batteries, and lithium ion secondary battery
CN104157811A (en) * 2013-12-11 2014-11-19 中航锂电（洛阳）有限公司 Lithium ion battery composite diaphragm and preparation method and application thereof

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11539101B2 (en) * 2017-05-12 2022-12-27 Panasonic Holdings Corporation Nonaqueous electrolyte secondary battery
US20200407543A1 (en) * 2018-03-02 2020-12-31 Arkema Inc. Fluoropolymer dispersion for separator coating
US11764441B2 (en) 2019-06-07 2023-09-19 Samsung Sdi Co., Ltd. Separator for rechargeable lithium battery and rechargeable lithium battery including the same
CN112054150A (en) * 2019-06-07 2020-12-08 三星Sdi株式会社 Separator for rechargeable lithium battery and rechargeable lithium battery including the same
CN112054150B (en) * 2019-06-07 2023-02-28 三星Sdi株式会社 Separator for rechargeable lithium battery and rechargeable lithium battery including the same
CN110707264A (en) * 2019-09-19 2020-01-17 河北金力新能源科技股份有限公司 High-conductivity coating diaphragm for lithium-sulfur battery and preparation method and application thereof
CN115836437A (en) * 2020-03-18 2023-03-21 宁德新能源科技有限公司 Electrochemical device and electronic device comprising same
US11843272B2 (en) 2020-03-19 2023-12-12 Ningde Amperex Technology Limited Electronic device and method for improving battery cycling performance
CN113795975A (en) * 2020-03-31 2021-12-14 宁德新能源科技有限公司 Separator, electrode assembly, battery, and electronic device
CN112670672A (en) * 2020-12-28 2021-04-16 横店集团东磁股份有限公司 Diaphragm for high-temperature storage, preparation method thereof and lithium ion battery
CN114144932B (en) * 2021-03-31 2024-04-05 宁德新能源科技有限公司 Separator, electrochemical device and electronic device comprising same
CN114144932A (en) * 2021-03-31 2022-03-04 宁德新能源科技有限公司 Isolating membrane, electrochemical device comprising same and electronic device
CN113054324A (en) * 2021-04-21 2021-06-29 上海恩捷新材料科技有限公司 High-safety diaphragm and battery
CN114024098A (en) * 2021-10-25 2022-02-08 珠海冠宇电池股份有限公司 Battery with a battery cell
CN114024098B (en) * 2021-10-25 2024-05-17 珠海冠宇电池股份有限公司 Battery cell
CN116093538B (en) * 2023-04-06 2023-07-14 宁德新能源科技有限公司 Electrode assembly, electrochemical device, and electronic device
CN116093538A (en) * 2023-04-06 2023-05-09 宁德新能源科技有限公司 Electrode assembly, electrochemical device, and electronic device

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