WO2023123751A1 - 一种涂覆隔膜及其制备方法 - Google Patents

一种涂覆隔膜及其制备方法 Download PDF

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WO2023123751A1
WO2023123751A1 PCT/CN2022/087599 CN2022087599W WO2023123751A1 WO 2023123751 A1 WO2023123751 A1 WO 2023123751A1 CN 2022087599 W CN2022087599 W CN 2022087599W WO 2023123751 A1 WO2023123751 A1 WO 2023123751A1
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coated
diaphragm
coating layer
preparation
film
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PCT/CN2022/087599
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English (en)
French (fr)
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庄志
马芸
周广盖
廖晨博
李文强
冶成良
程跃
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上海恩捷新材料科技有限公司
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Publication of WO2023123751A1 publication Critical patent/WO2023123751A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/403—Manufacturing processes of separators, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • 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 battery diaphragm preparation, and in particular relates to a high-viscosity coated diaphragm for lithium batteries.
  • thermal stability is mainly improved by coating the surface of the polyolefin separator with an inorganic coating layer, or a polymer coating layer is used to improve its bonding performance with the positive and negative electrodes, thereby improving the cycle life of the battery cell. and safety performance.
  • Invention patent CN109103397A discloses a method for preparing a ceramic material-coated diaphragm for lithium-ion batteries. The coated diaphragm improves the performance of the diaphragm by sequentially coating a polymer glue, a ceramic layer and a polymer bonding layer on the surface of the base film.
  • the design of the multi-layer coating layer increases the thickness of the diaphragm, which affects the weight and electrochemical performance of the battery cell; and the coating process is cumbersome and complicated, and the product production efficiency is low.
  • the polymer coating layer has a low absorption rate of the electrolyte, which increases the difficulty of liquid injection during the production of the battery cell; at the same time, the coating layer will affect the air permeability of the diaphragm, hinder the migration channel and rate of lithium ions, and have a greater impact on the internal resistance of the diaphragm. Electrochemical properties such as cell rate and cycle need to be sacrificed. Therefore, how to reduce the influence of the coating layer on the electrochemical performance of the cell while improving the performance of the coated separator has become an urgent problem to be solved for the coated separator.
  • the object of the present invention is to provide a kind of coating diaphragm, described coating diaphragm at least comprises base film and the coating layer that is coated on at least one side of base film, and described coating layer comprises porous PMMA microsphere, ceramic particle, Thickener, water-based adhesive and wetting agent, the porous PMMA microsphere D50 particle size is 1.0-4.0 ⁇ m, the porosity is 10%-40%, and the average pore size is 30nm-150nm.
  • the coated separator can not only adhere well to the positive and negative electrode materials, but also the porous PMMA microspheres in the coating layer of the separator can enhance the compatibility between the separator and the electrolyte, and further improve the air permeability of the separator.
  • the ceramic particles are any one or more of boehmite, aluminum oxide, barium sulfate and silicon dioxide.
  • the thickener is any one or more of methylcellulose, sodium carboxymethylcellulose, hydroxypropylmethylcellulose, polyacrylamide, and polyvinylpyrrolidone.
  • the water-based binder is any one or more of polyacrylic acid, polyurethane, polyacrylonitrile, polyacrylate; more preferably polymethacrylic acid, polyamino Any one or more of formate, polyacrylonitrile, polymethyl acrylate.
  • the wetting agent is any one or more of fatty alcohol polyoxyethyl ether, octylphenol polyoxyethylene ether, and sodium lauryl sulfate.
  • the base film may be any one of PE film, PP film, PE and PP composite film, PI film, PEI film and PET film.
  • the coating method is one of doctor blade coating, three-roll coating, hot melt coating, wire bar coating, extrusion bar coating, gravure coating or slot coating any of them.
  • the particle size of the ceramic particles is 0.2-0.5 ⁇ m.
  • the base film has a thickness of 5.0-16.0 ⁇ m.
  • the thickness of one side of the coating layer is 2.0-6.0 ⁇ m.
  • the present invention proposes a specific technical scheme for preparing the above-mentioned coated diaphragm, at least comprising the following steps:
  • Step S1 prepare porous PMMA microsphere:
  • Step S2 aqueous slurry preparation:
  • the aqueous slurry prepared in step S002 is coated on at least one side of the base film, and dried to obtain a coated separator.
  • the addition ratio of the dispersant, deionized water, MMA monomer, initiator and porogen is (0.5-2wt%): (85-93wt%): (3-5wt%): (0.01 -0.1wt%): (0.5-2.5wt%).
  • the porogen is any one or more of n-octanol, butyl acetate, dodecanol, cyclohexanol, and toluene.
  • the dispersant is any one or more of polyvinyl alcohol, Span 80, and polyvinylpyrrolidone.
  • the stirring speed of the polymerization reaction is 80-150 r/min, and the temperature is 50-80°C.
  • the drying temperature in step S3 is 50-80°C.
  • the beneficial effect of the present invention is that the coating diaphragm in the present invention is obtained by one-time coating of the slurry mixed with ceramic particles and porous PMMA microspheres, and the process is simple and feasible.
  • the present invention provides the method for preparing porous PMMA microsphere, can prepare D50 particle diameter by controlling the stirring velocity during polymer synthesis, porogen and MMA monomer mass ratio and dispersant aqueous solution concentration and be 1.0-4.0 ⁇ m, porosity 10%-40%, porous PMMA microspheres with a pore size of 30nm-150nm; the prepared porous microspheres are mixed with ceramic particles and coated on at least one side of the base film to form a coating layer, which can not only Improve the thermal shrinkage performance of the separator, and the porous polymer PMMA in the coating layer provides better circulation and liquid retention channels for the electrolyte, improves the wettability of the separator and the electrolyte, and can achieve rapid liquid injection.
  • the adverse effect of the coating on the air permeability improves its ionic conductivity and improves the rate performance and cycle performance of the cell.
  • the coating layer can increase the bonding performance of the diaphragm and the pole piece, reduce the risk of cell deformation, and improve the safety performance of the cell.
  • Fig. 1 is the diaphragm electrolyte contact angle test result in the embodiment and the comparative example
  • (1) is diaphragm electrolyte contact angle test result in embodiment 1;
  • Example 1 This example provides a coated separator, which contains porous PMMA microspheres with a particle diameter D50 of 3.8 ⁇ m, a porosity of 35%, and an average pore diameter of 150 nm.
  • Step S1 preparing porous PMMA microspheres
  • Preparation 500ml mass fraction is 2% polyvinyl alcohol (PVA) aqueous solution, in PVA solution, add 19.5g MMA monomer, 0.1g benzoyl peroxide and 10.5g n-octanol, stir with 65r/min at 70 °C React for 24 hours; after the polymerization is completed, fully wash with water, filter and dry; repeatedly soak the dried product in n-butanol, wash and filter three times, and fully dry to finally obtain a particle size D50 of 3.8 ⁇ m, a porosity of 35%, and an average pore size of Porous PMMA microspheres with a size of 150 nm.
  • PVA polyvinyl alcohol
  • Step S2 preparation of aqueous slurry
  • the above water-based mixed slurry was coated on both sides of a 9 ⁇ m PE film to form a water-based coating layer, and then dried in an oven at 60° C. to obtain a coated separator.
  • the average thickness of the single-side coating layer is 4.3 ⁇ m, and the surface density is 3.58 g/m 2 .
  • Example 2 This example provides a coated separator, which contains porous PMMA microspheres with a particle diameter D50 of 2.7 ⁇ m, a porosity of 23%, and an average pore diameter of 85 nm.
  • Step S1 preparing porous PMMA microspheres
  • Step S2 preparation of aqueous slurry
  • aqueous mixed slurry was coated on one side of a 9 ⁇ m PE film to form an aqueous coating layer, and then dried in an oven at 50° C. to obtain a coated separator.
  • the average thickness of the single-side coating layer is 3.2 ⁇ m, and the surface density is 3.39 g/m 2 .
  • Example 3 This example provides a coated separator, which contains porous PMMA microspheres with a particle diameter D50 of 1.2 ⁇ m, a porosity of 11%, and an average pore diameter of 35 nm.
  • Step S1 preparing porous PMMA microspheres
  • Step S2 preparation of aqueous slurry
  • the above water-based mixed slurry was coated on both sides of the 9 ⁇ m PE base film to form a water-based coating layer, and then dried in an oven at 50° C. to obtain a coated separator.
  • the average thickness of the single-side coating layer is 2.9 ⁇ m, and the surface density is 3.28 g/m 2 .
  • Example 4 This example provides a coated separator, which contains porous PMMA microspheres with a particle size D50 of 2.5 ⁇ m, a porosity of 21%, and an average pore size of 83 nm.
  • Step S1 preparing porous PMMA microspheres
  • Step S1 preparation of aqueous slurry
  • aqueous mixed slurry was coated on one side of a 9 ⁇ m PP film to form an aqueous coating layer, and then dried in an oven at 50° C. to obtain a coated separator.
  • the average thickness of the single-side coating layer is 3.4 ⁇ m, and the surface density is 3.36 g/m 2 .
  • Step S1 preparing PMMA microspheres
  • PVA polyvinyl alcohol
  • Step S2 preparation of aqueous slurry
  • aqueous mixed slurry was coated on one side of a 9 ⁇ m PE film to form an aqueous coating layer, and then dried in an oven at 50° C. to obtain a coated separator.
  • the average thickness of the single-side coating layer is 3.3 ⁇ m, and the surface density is 3.99 g/m 2 .
  • the diaphragms of each embodiment and comparative example were tested for surface density, thickness, air permeability, electrical conductivity, heat shrinkage and adhesion.
  • the data are shown in Table 2.
  • the detection instruments used in the above test items are: electronic balance, Mahr Millimar Thickness gauge, air permeability tester, electrochemical workstation, oven and universal tensile testing machine.
  • the thermal shrinkage test method is: put the separator in an oven at 150°C for 1 hour, and calculate the percentage of the length change in the MD direction to the initial size of the separator, which is the thermal shrinkage rate.
  • the method for testing the bonding strength is as follows: heat-press the 85 ⁇ 140mm negative plate and the separator at 90°C with a pressure of 3.5MPa for 60s, cut it into a 30 ⁇ 140mm sample strip, and test it on a universal tensile testing machine with The test was carried out at a tensile rate of 300mm/min, and the obtained data was the adhesion force between the separator and the negative electrode sheet.
  • the porous polymer-coated diaphragms in each embodiment have better air permeability, and at the same time, the conductivity of the porous polymer-coated diaphragm is higher than that of the solid polymer-coated
  • the separators and pole pieces of the examples and comparative examples all exhibited excellent thermal shrinkage performance and bonding performance. 3.
  • the water-based coated separators prepared in each example and comparative case were respectively combined with lithium cobaltate positive pole pieces and graphite negative pole pieces to make a soft-packed lithium-ion battery through a winding process, and the rate performance test and cycle performance test were carried out .
  • the rate performance test method is: charge the lithium-ion battery with constant current and constant voltage to 4.25V at the current of 0.5C, 1C, 3C, and 5C respectively, and the cut-off current is 0.2C. time.
  • the cycle performance test method is: cycle the lithium-ion battery 500 times at a charge-discharge rate of 3C, and record its capacity retention rate relative to the initial capacity.
  • the test data are shown in Table 3.

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Abstract

本发明提供一种锂电池隔膜，具体涉及一种涂覆隔膜。所述涂覆隔膜至少包括基膜及涂覆于基膜至少一侧的涂覆层，所述涂覆层至少包括多孔PMMA微球、陶瓷颗粒、增稠剂、水性粘接剂以及润湿剂，所述多孔PMMA微球粒径D50为1.0-4.0μm，孔隙率为10％-40％，平均孔径大小为30nm-150nm。该涂覆层不但能提高隔膜热收缩性能，而且涂覆层中多孔PMMA微球为电解液提供更好的流通和保液通道，改善隔膜的电解液浸润性，可实现快速注液，同时，可降低聚合物涂覆层对透气度的不利影响，提高其离子导电率，改善电芯倍率性能与循环性能。此外，该涂覆层能增加隔膜与极片粘接性能，减小电芯变形风险，改善电芯安全性能。

Description

一种涂覆隔膜及其制备方法 技术领域
本发明属于电池隔膜制备领域，具体涉及一种具备高粘性的锂电池用涂覆隔膜。
背景技术
随着锂电池应用领域的快速发展，传统的聚烯烃隔膜难以满足市场需求。作为电池的重要组成部分，隔膜性能的改善对提高锂电池电化学性能和安全性能有着至关重要的影响。
目前已有的报道中，主要通过在聚烯烃隔膜表面涂覆无机涂覆层提高热稳定性能，或聚合物涂覆层来改善其与正、负极片粘接性能，从而提高电芯循环使用寿命和安全性能。发明专利CN109103397A公开了一种锂离子电池用陶瓷材料涂覆隔膜的制备方法，该涂覆隔膜通过在基膜表面依次涂覆聚合物胶液、陶瓷层以及聚合物粘结层来改善隔膜性能。但是多层涂覆层的设计增加了隔膜厚度，影响电芯重量和电化学性能；且涂覆工序繁琐复杂，产品生产效率低。此外，聚合物涂覆层对电解液吸收速率低，增加电芯生产过程中注液难度；同时涂覆层会影响隔膜透气性能，阻碍锂离子迁移通道和速率，对隔膜内阻影响较大，需要牺牲电芯倍率、循环等电化学性能。因此，如何在改善涂覆隔膜性能的同时降低涂覆层对电芯电化学性能的影响，成为涂覆隔膜亟需解决的问题。
发明内容
本发明的目的在于提供一种涂覆隔膜，所述涂覆隔膜至少包括基膜及涂 覆于基膜至少一侧的涂覆层，所述涂覆层至少包括多孔PMMA微球、陶瓷颗粒、增稠剂、水性粘接剂以及润湿剂，所述多孔PMMA微球D50粒径为1.0-4.0μm，孔隙率为10％-40％，平均孔径大小为30nm-150nm。该涂覆隔膜不仅能良好的贴紧正负极材料，且隔膜涂覆层中多孔PMMA微球可以增强隔膜与电解液的相容性，更能提升隔膜的透气性。
可选的，所述陶瓷颗粒为勃姆石、三氧化二铝、硫酸钡以及二氧化硅中的任意一种或多种。
可选的，所述增稠剂为甲基纤维素、羧甲基纤维素钠、羟丙基甲基纤维素、聚丙烯酰胺、聚乙烯吡咯烷酮中的任意一种或多种。
可选的，其特征在于，所述水性粘结剂为聚丙烯酸类、聚氨酯类、聚丙烯腈类、聚丙烯酸酯类中的任意一种或多种；更优选系聚甲基丙烯酸、聚氨基甲酸酯、聚丙烯腈、聚丙烯酸甲酯中的任意一种或多种。
可选的，所述润湿剂为脂肪醇聚氧乙醚、辛基酚聚氧乙烯醚、十二烷基硫酸钠中的任意一种或多种。
可选的，所述基膜可以是PE膜、PP膜、PE与PP复合膜、PI膜、PEI膜以及PET膜中的任意一种。
可选的，所述涂布方式为刮刀逗式涂布、三辊涂布、热熔涂布、线棒式涂布、挤压式刮棒涂布、凹版涂布或狭缝式涂布之中任意一种。
可选的，陶瓷颗粒粒径为0.2-0.5μm。
可选的，所述基膜的厚度为5.0-16.0μm。
可选的，所述涂覆层单面厚度为2.0-6.0μm。
更进一步的，本发明提出了一种制备上述涂覆隔膜的具体技术方案，至 少包括以下步骤：
步骤S1，制备多孔PMMA微球:
将分散剂加入去离子水配制分散剂的水溶液；在分散剂的水溶液中加入MMA单体、引发剂和致孔剂，在一定的搅拌速度和温度下进行聚合反应；将聚合产物用去离子水水充分洗涤、干燥；然后将干燥后的聚合产物用溶剂反复浸泡、洗涤、过滤，干燥后得到多孔PMMA微球；
步骤S2，水性浆料配制:
将陶瓷颗粒、增稠剂和去离子水混合均匀后，加入水性粘接剂、润湿剂以及多孔PMMA微球并搅拌分散均匀，得到水性浆料；
步骤S3，涂布:
将步骤S002中所配制的水性浆料涂覆于基膜至少一侧，干燥后得到涂覆隔膜。
可选的，所述分散剂、去离子水、MMA单体、引发剂和致孔剂添加量比例为(0.5-2wt％):(85-93wt％):(3-5wt％):(0.01-0.1wt％):(0.5-2.5wt％)。
可选的，所述致孔剂为正辛醇、乙酸丁酯、十二烷醇与环己醇、甲苯中的任意一种或多种。
可选的，所述分散剂为聚乙烯醇、Span 80、聚乙烯吡咯烷酮中的任意一种或多种。
可选的，所述步骤S1中聚合反应搅拌速度为80-150r/min，温度为50-80℃。
可选的，所述步骤S3中干燥温度为50-80℃。
本发明的有益效果是本发明中的涂覆隔膜为陶瓷颗粒与多孔PMMA微球混合浆料一次涂覆所得，工艺简单可行。且本发明提供了制备多孔PMMA微 球的方法，通过控制聚合物合成时的搅拌速度、致孔剂与MMA单体质量比例以及分散剂水溶液浓度可以制备D50粒径为1.0-4.0μm，孔隙率为10％-40％，孔径大小在30nm-150nm的多孔PMMA微球；将制备的多孔微球与陶瓷颗粒等混合后涂覆于基膜至少一侧形成涂覆层，该涂覆层不但能提高隔膜热收缩性能，而且涂覆层中多孔聚合物PMMA为电解液提供更好的流通和保液通道，改善隔膜与电解液浸润性，可实现快速注液，同时，可降低以往聚合物涂覆层对透气度的不利影响，提高其离子导电率，改善电芯倍率性能与循环性能。此外，该涂覆层能增加隔膜与极片粘接性能，减小电芯变形风险，提高电芯安全性能。
附图说明
图1为实施例与对比例中隔膜电解液接触角测试结果；
其中，(1)为实施例1中隔膜电解液接触角测试结果；
其中(2)为实施例2中隔膜电解液接触角测试结果；
其中(3)为实施例3中隔膜电解液接触角测试结果；
其中(4)为实施例4中隔膜电解液接触角测试结果；
其中(5)为对比例1中隔膜电解液接触角测试结果。
具体实施方式
为进一步了解本发明，下面结合具体实施方式对本发明的优选方案进行描述，以利于本领域技术人员理解本发明。
实施例1本实施例提供一种涂覆隔膜，其中包含粒径D50为3.8μm，孔隙率为35％，平均孔径为150nm的多孔PMMA微球。
具体的制备方法如下：
步骤S1，制备多孔PMMA微球；
配制500ml质量分数为2％的聚乙烯醇(PVA)水溶液，向PVA溶液中加入19.5g MMA单体、0.1g过氧化苯甲酰和10.5g正辛醇，在70℃下以65r/min搅拌反应24小时；聚合完成后用水充分洗涤、过滤和干燥；将干燥的产物用正丁醇反复浸泡、洗涤、过滤三次，充分干燥最终得到粒径D50为3.8μm，孔隙率为35％，平均孔径大小为150nm的多孔PMMA微球。
步骤S2，水性浆料配制；
将48g三氧化二铝与1.2g的羧甲基纤维素钠分散剂加入133.3g去离子水中，以1000rpm的搅拌速度分散100min后，将所得混合溶液置于研磨机中研磨3遍；往上述所制得的溶液中依次加入6.7g聚丙烯酸酯粘接剂和0.4g脂肪醇聚氧乙醚润湿剂，以500rpm搅拌60min后，得到均匀分散的陶瓷浆料；最后加入9.0g所述步骤S1中制备的多孔PMMA微球，以500rpm的速度分散30min后，得到水性浆料。
步骤S3，涂布；
将上述水性混合浆料涂覆于9μm PE膜的两侧，形成水性涂覆层，再置于60℃的烘箱烘干，得到涂覆隔膜。其中，单面涂覆层平均厚度为4.3μm，面密度为3.58g/m 2。
实施例2本实施例提供一种涂覆隔膜，其中包含粒径D50为2.7μm，孔隙率为23％，平均孔径为85nm的多孔PMMA微球。
具体的制备方法如下：
步骤S1，制备多孔PMMA微球；
配置500ml 2％的聚乙烯醇(PVA)水溶液，向PVA溶液中加入22.5g MMA单体、0.1g过氧化苯甲酰和7.5g正辛醇，在70℃下以100r/min搅拌反应24小时；聚合完成后用水充分洗涤、过滤和干燥；将干燥的产物用正丁醇反复浸泡、洗涤、过滤三次，充分干燥最终得到粒径D50为2.7μm，孔隙率为23％，孔径大小为85nm的多孔PMMA微球。
步骤S2，水性浆料配制；
将48g三氧化二铝与1.2g羧甲基纤维素钠分散剂加入133.3g去离子水中，以1000rpm的搅拌速度分散100min后，将所得混合溶液置于研磨机中研磨3遍；往上述所制得的溶液中依次加入6.7g聚丙烯酸酯粘接剂和0.4g脂肪醇聚氧乙醚润湿剂，以500rpm搅拌60min后，得到均匀分散的陶瓷浆料；最后加入9.0g所述步骤S1中制备的多孔PMMA微球，以500rpm的搅拌速度均匀分散30min后，得到水性浆料。
步骤S3，涂布；
将上述水性混合浆料涂覆于9μm PE膜的一侧，形成水性涂覆层，再置于50℃的烘箱烘干，得到涂覆隔膜。其中，单面涂覆层平均厚度为3.2μm，面密度为3.39g/m 2。
实施例3本实施例提供一种涂覆隔膜，其中包含粒径D50为1.2μm，孔隙率为11％，平均孔径为35nm的多孔PMMA微球。
具体的制备方法如下：
步骤S1，制备多孔PMMA微球；
配置500ml 2％的聚乙烯醇(PVA)水溶液，向PVA溶液中加入26.4g MMA单体、0.1g过氧化苯甲酰和3.6g正辛醇，在70℃下以135r/min搅拌反应24 小时；聚合完成后用水充分洗涤、过滤和干燥；将干燥的产物用正丁醇反复浸泡、洗涤、过滤三次，充分干燥最终得到粒径D50为1.2μm，孔隙率为11％，平均孔径大小为40nm的多孔PMMA微球。
步骤S2，水性浆料配制；
将48g三氧化二铝与1.2g羧甲基纤维素钠分散剂加入133.3g去离子水中，以1000rpm的搅拌速度分散100min后，将所得混合溶液置于研磨机中研磨3遍；往上述溶液中依次加入6.7g聚丙烯酸酯粘接剂和0.4g脂肪醇聚氧乙醚润湿剂，以500rpm搅拌60min后，得到均匀分散的陶瓷浆料；最后加入9.0g所述步骤S1中制备的多孔PMMA微球，以500rpm的搅拌速度均匀分散30min后，得到水性浆料。
步骤S3，涂布；
将上述水性混合浆料涂覆于9μm PE基膜的两侧，形成水性涂覆层，再置于50℃的烘箱烘干，得到涂覆隔膜。其中，单面涂覆层平均厚度为2.9μm，面密度为3.28g/m 2。
实施例4本实施例提供一种涂覆隔膜，其中包含粒径D50为2.5μm，孔隙率为21％，平均孔径为83nm的多孔PMMA微球。
具体的制备方法如下：
步骤S1，制备多孔PMMA微球；
配置500ml 2％的聚乙烯吡咯烷酮水溶液，向上述溶液中加入22.5g MMA单体、0.1g过氧化苯甲酰和7.5g正辛醇，在70℃下以100r/min搅拌反应24小时；聚合完成后用水充分洗涤、过滤和干燥；将干燥的产物用正丁醇反复浸泡、洗涤、过滤三次，充分干燥最终得到粒径D50为2.5μm，孔隙率为21％，平 均孔径大小为83nm的多孔PMMA微球。
步骤S1，水性浆料配制；
将48g三氧化二铝与1.2g羧甲基纤维素钠分散剂加入137g去离子水中，以1000rpm的搅拌速度分散100min后，将所得混合溶液置于研磨机中研磨3遍；往上述溶液中依次加入3.0g丙烯腈粘接剂和0.4g脂肪醇聚氧乙醚润湿剂，以500rpm搅拌60min后，得到均匀分散的陶瓷浆料；最后加入9.0g所述步骤S1中制备的多孔PMMA微球，以500rpm的搅拌速度均匀分散30min后，得到水性浆料。
步骤S1，涂布；
将上述水性混合浆料涂覆于9μm PP膜的一侧，形成水性涂覆层，再置于50℃的烘箱烘干，得到涂覆隔膜。其中，单面涂覆层平均厚度为3.4μm，面密度为3.36g/m 2。
对比例1
步骤S1，制备PMMA微球；
配置500ml 2％的聚乙烯醇(PVA)水溶液，向PVA溶液中加入30g MMA单体、0.1g过氧化苯甲酰，在70℃下以100r/min搅拌反应24小时；聚合完成后用水充分洗涤、过滤和干燥，最终得到平均粒径为2.7μm PMMA微球。
步骤S2，水性浆料配制；
将48g三氧化二铝与1.2g羧甲基纤维素钠分散剂加入133.3g去离子水中，以1000rpm的搅拌速度分散100min后，将所得混合溶液置于研磨机中研磨3遍；往上述溶液中依次加入6.7g聚丙烯酸酯粘接剂和0.4g脂肪醇聚氧乙醚润湿剂，500rpm搅拌60min后，得到均匀分散的陶瓷浆料；最后加入9.0g所述步骤 S1中制备的多孔PMMA微球，以500rpm的搅拌速度均匀分散30min后，得到水性浆料。
步骤S3，涂布；
将上述水性混合浆料涂覆于9μm PE膜的一侧，形成水性涂覆层，再置于50℃的烘箱烘干，得到涂覆隔膜。其中，单面涂覆层平均厚度为3.3μm，面密度为3.99g/m 2。
将具体实施例1-4与对比例1中制备的隔膜进行电解液吸液率及保液率(吸液后静置1h后)测试，测试结果如表1：
表1.
项目 实施1 实施2 实施3 实施4 对比例1
吸液率(％) 147 139 131 135 119
保液率(％) 132 125 118 123 98
接触角(°) / / 8.5 / 17.4
由表1可知，具体实施1-4都有较好的吸液率和保液率，且均高于对比例，说明多孔涂覆层为隔膜对电解液的吸附提供了通道。涂覆隔膜与电解液的接触角随聚合物孔隙率的增加而减小，这说明聚合物的多孔结构所具备的毛细现象有利于提高聚合物涂覆层隔膜对电解液的吸收速度和吸收量，能够改善其电解液浸润性。附图1为实施例1、实施例2、实施例3、实施例4及对比例1中制备的隔膜与电解液接触角测试结果。
将各实施例与对比例的隔膜进行面密度、厚度、透气性、电导率、热收缩以及粘接力测试，数据参见表2，以上测试项目所用到的检测仪器依次为：电子天平、Mahr Millimar厚度仪、透气度测试仪、电化学工作站、烘箱以及万能拉伸试验机。
其中，热收缩测试方法为：将隔膜置于150℃的烘箱烘烤1h，计算其MD方向长度变化与隔膜初始尺寸的百分比即为热收缩率。
粘接强度测试时方法为：将85×140mm的负极片与隔膜在90℃温度下采用3.5MPa的压力热压60s，将其裁剪成30×140mm的样条后，在万能拉伸试验机上以300mm/min的拉伸速率进行测试，所得到的数据为隔膜与负极片的粘接力。
表2.
Figure PCTCN2022087599-appb-000001
由上表数据分析可得，相比于对比例，各实施案例中的多孔聚合物涂覆隔膜具有更好的透气性，同时，多孔聚合物涂覆隔膜电导率值高于实心聚合物涂覆隔膜，且随聚合物孔隙率增大，其离子电导率变高，这说明多孔聚合物涂覆层有利于提高电芯离子电导率，改善电芯倍率及其它电化学性能。同时，各实施例与对比例隔膜跟极片均表现出优异的热收缩性能和粘接性能。三.将各实施例与对比案例所制备的水性涂覆隔膜，分别与钴酸锂正极极片和石墨负极极片通过卷绕工艺制成软包锂离子电池，进行倍率性能测试和循环性能测试。
倍率性能测试方法为：将锂离子电池分别以以0.5C、1C、3C、5C的电 流进行恒流恒压充电至4.25V，截止电流为0.2C，记录不同充电倍率充至满电状态所需要的时间。
循环性能测试方法为：将锂离子电池在3C的充放电倍率下循环500次，记录其相对于初始容量的容量保持率。测试数据见表3。
表3.
Figure PCTCN2022087599-appb-000002
上表的结果显示，在0.5C、1C倍率条件下下，各实施例与对比例充至满电状态所需时间相近，但随充电倍率的增加，实施例与对比例的差异明显。以上结果说明聚合物涂覆层的多孔结构为电解液提供更好的流通通道，改善电芯内阻，有利于其快充性能的优化。同时，从电芯在3C充/放电下的循环测试结果来看，各实施例表现出了更明显的电化学稳定性能。
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，在不脱离本发明构思的前提下，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范围。

Claims (15)

  1. 一种涂覆隔膜，至少包括基膜及涂覆于基膜至少一侧的涂覆层，其特征在于，所述涂覆层至少包括多孔PMMA微球、陶瓷颗粒、增稠剂、水性粘接剂以及润湿剂，所述多孔PMMA微球平均粒径为1.0-4.0μm，孔隙率为10％-40％，平均孔径大小为30nm-150nm。
  2. 如权利要求1所述的涂覆隔膜，其特征在于，所述陶瓷颗粒为勃姆石、三氧化二铝、硫酸钡以及二氧化硅中的任意一种或多种，颗粒粒径为0.2-0.5μm。
  3. 如权利要求1所述的涂覆隔膜，其特征在于，所述增稠剂为甲基纤维素、羧甲基纤维素钠、羟丙基甲基纤维素、聚丙烯酰胺、聚乙烯吡咯烷酮中的任意一种或多种。
  4. 如权利要求1所述的涂覆隔膜，其特征在于，所述水性粘结剂为聚丙烯酸类、聚氨酯类、聚丙烯腈类、聚丙烯酸酯类的任意一种或多种。
  5. 如权利要求1所述的涂覆隔膜，其特征在于，所述润湿剂为脂肪醇聚氧乙醚、辛基酚聚氧乙烯醚、十二烷基硫酸钠中的任意一种或多种。
  6. 如权利要求1所述的涂覆隔膜，其特征在于，所述基膜可以是PE膜、PP膜、PE与PP复合膜、PI膜、PEI膜以及PET膜中的任意一种。
  7. 如权利要求1所述的涂覆隔膜，其特征在于，所述基膜的厚度为5.0-16.0μm。
  8. 如权利要求1所述的涂覆隔膜，其特征在于，所述涂覆层单面厚度为2.0-6.0μm。
  9. 一种如权利要求1-8任意一项所述的涂覆隔膜的制备方法，其特征在于，至少包括以下步骤：
    步骤S1，制备多孔PMMA微球:
    将分散剂加入去离子水配制分散剂的水溶液；在分散剂的水溶液中加入MMA单体、引发剂和致孔剂，在一定的搅拌速度和温度下进行聚合反应；将聚合产物用去离子水水充分洗涤、干燥；然后将干燥后的聚合产物用溶剂反复浸泡、洗涤、过滤，干燥后得到多孔PMMA微球；
    步骤S2，水性浆料配制:
    将陶瓷颗粒、增稠剂和去离子水混合均匀后，加入水性粘接剂、润湿剂以及多孔PMMA微球并搅拌分散均匀，得到水性浆料；
    步骤S3，涂布:
    将步骤S2中所配制的水性浆料涂覆于基膜的至少一侧，干燥后得到涂覆隔膜。
  10. 如权利要求9所述的制备方法，其特征在于，所述分散剂、去离子水、MMA单体、引发剂和致孔剂添加量比例为(0.5-2wt％):(85-93wt％):(3-5wt％):(0.01-0.1wt％):(0.5-2.5wt％)。
  11. 如权利要求9所述的制备方法，其特征在于，所述致孔剂为正辛醇、乙酸丁酯、十二烷醇与环己醇、甲苯中的任意一种或多种。
  12. 如权利要求9所述的制备方法，其特征在于，所述分散剂为聚乙烯醇、Span 80、聚乙烯吡咯烷酮中的任意一种或多种。
  13. 如权利要求9所述的制备方法，所述陶瓷颗粒、增稠剂、去离子水、水性粘接剂、润湿剂以及多孔PMMA微球的添加比例为(12-35wt％):(0.2-2wt％):(55-80wt％):(0.5-5wt％):(0.01-0.6wt％):(2-10wt％)。
  14. 如权利要求9所述的制备方法，其特征在于，所述步骤S1中搅拌 速度为80-150r/min，温度为50-80℃。
  15. 如权利要求9所述的制备方法，其特征在于，所述步骤S3中干燥温度为50-80℃。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117060011A (zh) * 2023-10-09 2023-11-14 宁德卓高新材料科技有限公司 一种涂覆隔膜及其制备方法及应用

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114361706A (zh) * 2021-12-29 2022-04-15 上海恩捷新材料科技有限公司 一种涂覆隔膜及其制备方法
CN114843703B (zh) * 2022-05-18 2023-09-22 江苏厚生新能源科技有限公司 一种具有不规则形状颗粒涂层的电池隔膜及其制备方法
CN115832624A (zh) * 2022-12-07 2023-03-21 广东卓高新材料科技有限公司 一种锂离子电池复合涂覆隔膜及其制备方法
CN115954616B (zh) * 2022-12-29 2023-08-15 广东卓高新材料科技有限公司 一种基于mof材料的涂层隔膜及其制备方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104844751A (zh) * 2015-05-17 2015-08-19 北京化工大学 一种微米级交联聚合物空心微球及其制备方法
US20160009892A1 (en) * 2013-04-03 2016-01-14 Cosmax Co., Ltd. Method for preparing macroporous polymethyl methacrylate
CN106784531A (zh) * 2016-08-29 2017-05-31 东莞市卓高电子科技有限公司 一种pmma及其共聚物混合涂覆隔膜的制备方法
CN109786749A (zh) * 2019-02-18 2019-05-21 珠海光宇电池有限公司 一种交联sbr微球粘结剂及制备方法及含有该粘结剂的锂离子电池
CN110137416A (zh) * 2019-05-15 2019-08-16 武汉理工大学 一种聚烯烃锂电隔膜制备方法
CN110444718A (zh) * 2019-08-15 2019-11-12 宁德卓高新材料科技有限公司 具有高粘结性聚合物涂膜的陶瓷复合隔膜的制备方法
CN111129404A (zh) * 2019-12-25 2020-05-08 河北金力新能源科技股份有限公司 一种改性pmma隔膜浆料、锂电池隔膜及其制备方法及应用
CN114361706A (zh) * 2021-12-29 2022-04-15 上海恩捷新材料科技有限公司 一种涂覆隔膜及其制备方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103078077B (zh) * 2013-01-17 2015-03-25 中国科学院金属研究所 一种特殊结构锂离子电池隔膜及其制备方法
CN106328865B (zh) * 2015-06-19 2019-06-11 宁德时代新能源科技股份有限公司 隔离膜及锂离子二次电池
CN113169418B (zh) * 2019-01-22 2022-11-18 东莞东阳光科研发有限公司 聚酰亚胺微球浆料、复合隔膜及锂离子电池
CN113394513A (zh) * 2021-05-28 2021-09-14 湖南中锂新材料有限公司 一种复合涂层结构的隔膜的制备方法
CN113471629B (zh) * 2021-06-25 2022-10-04 湖南中锂新材料有限公司 一种复合涂层结构的隔膜及其制备方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160009892A1 (en) * 2013-04-03 2016-01-14 Cosmax Co., Ltd. Method for preparing macroporous polymethyl methacrylate
CN104844751A (zh) * 2015-05-17 2015-08-19 北京化工大学 一种微米级交联聚合物空心微球及其制备方法
CN106784531A (zh) * 2016-08-29 2017-05-31 东莞市卓高电子科技有限公司 一种pmma及其共聚物混合涂覆隔膜的制备方法
CN109786749A (zh) * 2019-02-18 2019-05-21 珠海光宇电池有限公司 一种交联sbr微球粘结剂及制备方法及含有该粘结剂的锂离子电池
CN110137416A (zh) * 2019-05-15 2019-08-16 武汉理工大学 一种聚烯烃锂电隔膜制备方法
CN110444718A (zh) * 2019-08-15 2019-11-12 宁德卓高新材料科技有限公司 具有高粘结性聚合物涂膜的陶瓷复合隔膜的制备方法
CN111129404A (zh) * 2019-12-25 2020-05-08 河北金力新能源科技股份有限公司 一种改性pmma隔膜浆料、锂电池隔膜及其制备方法及应用
CN114361706A (zh) * 2021-12-29 2022-04-15 上海恩捷新材料科技有限公司 一种涂覆隔膜及其制备方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117060011A (zh) * 2023-10-09 2023-11-14 宁德卓高新材料科技有限公司 一种涂覆隔膜及其制备方法及应用
CN117060011B (zh) * 2023-10-09 2024-03-29 宁德卓高新材料科技有限公司 一种涂覆隔膜及其制备方法及应用

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