WO2018170929A1 - 一种负极和隔膜一体化结构及其制备方法和电池 - Google Patents

一种负极和隔膜一体化结构及其制备方法和电池 Download PDF

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WO2018170929A1
WO2018170929A1 PCT/CN2017/078207 CN2017078207W WO2018170929A1 WO 2018170929 A1 WO2018170929 A1 WO 2018170929A1 CN 2017078207 W CN2017078207 W CN 2017078207W WO 2018170929 A1 WO2018170929 A1 WO 2018170929A1
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integrated structure
negative electrode
metal foil
organic polymer
polymer film
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PCT/CN2017/078207
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English (en)
French (fr)
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唐永炳
张松全
王蒙
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深圳先进技术研究院
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Priority to PCT/CN2017/078207 priority Critical patent/WO2018170929A1/zh
Publication of WO2018170929A1 publication Critical patent/WO2018170929A1/zh

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    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

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  • the invention relates to the technical field of secondary batteries, in particular to an integrated structure of a negative electrode and a diaphragm, a preparation method thereof and a battery.
  • the production process of the existing secondary battery is cumbersome, including positive and negative electrode mixing, coating, rolling, sheeting, welding of the ear, winding, shelling, drying, liquid injection, standing, sealing,
  • the steps of chemical production, capacity separation, etc. have high requirements on the proficiency of production plants, automation equipment and personnel, and the initial investment is large.
  • the first aspect of the present invention provides an integrated structure of a negative electrode and a diaphragm, which can effectively reduce the volume and weight of the battery, simplify the production process, increase the overall capacity and energy density of the battery, and improve the battery. High rate performance and high temperature performance.
  • the present invention provides an integrated structure of a negative electrode and a separator, including a metal foil and a setting A porous organic polymer film on the surface of the metal foil, which simultaneously serves as a negative electrode current collector and a negative electrode active material, the porous organic polymer film serving as a separator.
  • the porous organic polymer film may be formed on one side surface of the metal foil or may be formed on the entire surface of the metal foil according to a specific application.
  • one electrode unit When formed on one side surface, one electrode unit may be formed with the positive electrode to form a button type battery or the like; when formed on the entire surface, a plurality of stacked electrode units may be formed with the positive electrode to form a wound type commercial battery or the like.
  • the metal foil and the lithium ion are charged and discharged by alloying-de-alloying reaction.
  • the material of the metal foil includes any one of titanium, manganese, chromium, gallium, magnesium, vanadium, niobium, indium, aluminum, copper, iron, tin, nickel, zinc, lithium, or contains at least one of the above metals.
  • the alloy of the elements Some surface states or dangling bonds on the surface of the metal foil may interact with the organic polymer in the porous organic polymer film to have a certain force between the two.
  • the surface of the metal foil is provided with a concave pattern, and the porous organic polymer film is partially disposed in the concave pattern to make the porous organic polymer film more tightly bonded to the metal foil.
  • the specific shape of the concave pattern is not particularly limited and may be regular or irregular.
  • the groove pattern of the concave pattern may have a depth of 0.1 ⁇ m to 5 ⁇ m.
  • the surface of the metal foil is modified with an organic substance containing an amphoteric functional group, and the organic compound containing the amphoteric functional group chemically interacts with the organic polymer in the porous organic polymer film to make the porous organic polymer film
  • the metal foil is tightly bonded.
  • the anion group-containing organic substance may be an organosilane coupling agent, a chromium complex coupling agent, a titanate coupling agent, or the like.
  • the material of the porous organic polymer film comprises polyethylene oxide, polymethyl methacrylate, polyvinylidene fluoride-hexafluoropropylene, polyoxypropylene, polyvinyl acetal, polyvinylpyrrolidone, sulfonylurea polymer, poly Phenyl sulfone sulfonic acid polymer, polyethylene oxide, styrene butadiene rubber, polybutadiene, polyvinyl chloride, polystyrene One or more of alkene, acrylate, chitosan, polyvinyl alcohol, polyvinyl butyral, polyethylene glycol, polyether acrylate, polyethylene, polypropylene, phosphate polymer , or a blending, copolymerization, grafting, combing, hyperbranched or crosslinked network of any one or more of the above polymers.
  • the porous organic polymer film has a thickness of 5 to 100 ⁇ m. Further it may be 20-60 ⁇ m.
  • the porous organic polymer film is prepared or disposed on the surface of the metal foil by hot pressing, knife coating, spin coating or rolling.
  • the present invention provides a method for preparing an integrated structure of a negative electrode and a separator, comprising the following steps:
  • the material of the metal foil comprises any one of titanium, manganese, chromium, gallium, magnesium, vanadium, niobium, indium, aluminum, copper, iron, tin, nickel, zinc, lithium, or at least one kind An alloy of the above metal elements.
  • the organic polymer-containing slurry includes an organic polymer and a solvent including acetone, N-2-methylpyrrolidone, tetrahydrofuran, toluene, chloroform, triethanolamine, cyclohexane, diethyl ether, methyl carbonate, and the like.
  • the organic polymer may be polyethylene oxide, polymethyl methacrylate, polyvinylidene fluoride-hexafluoropropylene, polyoxypropylene, polyvinyl acetal, polyvinylpyrrolidone, sulfonylurea polymer, polyphenylene Sulfone sulfonic acid polymer, polyethylene oxide, styrene butadiene rubber, polybutadiene, polyvinyl chloride, polystyrene, acrylate, chitosan, polyvinyl alcohol, polyvinyl butyral, polyethylene Alcohol, polyether acrylate, One or more of polyethylene, polypropylene, phosphate polymers, or blending, copolymerization, grafting, combing, hyperbranched or crosslinked network of any one or more of the above polymers.
  • the organic polymer precursor is a precursor material of the above organic polymer.
  • the doctor blade has a thickness of 10 to 100 ⁇ m, the spin coating speed is 10 to 10,000 rpm, and the spin coating time is 5 to 1200 s.
  • the hot pressing temperature is 80-300 ° C
  • the hot pressing pressure is 5-100 MPa
  • the hot pressing time is 10-1200 s
  • the rolling pressure is 50-150 MPa.
  • a concave shape is formed on the surface of the metal foil before the porous organic polymer film is prepared or disposed.
  • the concave pattern can be prepared by sanding, molding, laser etching or chemical etching.
  • the specific shape of the concave pattern is not particularly limited and may be regular or irregular.
  • the groove pattern of the concave pattern may have a depth of 0.1 ⁇ m to 5 ⁇ m.
  • the organic substance containing the bis-functional group is modified on the surface of the metal foil before the preparation or setting of the porous organic polymer film.
  • the specific operation is: immersing the metal foil in a solution of an organic substance containing an bis-functional group to complete surface modification.
  • the organic substance containing the bis-functional group may be further modified on the surface of the metal foil provided with the concave pattern.
  • the anion group-containing organic substance may be an organosilane coupling agent, a chromium complex coupling agent, a titanate coupling agent, or the like.
  • the present invention provides a battery comprising a positive electrode, an electrolyte, and a negative electrode and separator integrated structure according to the first aspect of the present invention, the positive electrode including a positive electrode current collector and a positive electrode current collector A positive active material layer on the positive electrode active material layer including a positive electrode active material.
  • the positive electrode is adjacent to the side of the porous organic polymer membrane of the negative electrode and separator integrated structure.
  • the positive electrode material includes LiCoO 2 , LiMnO 2 , LiNiO 2 , LiFeO 2 , LiFePO 4 , (Li(Ni x Co y Mn 1-xy )O 2 , Li(Ni x Co y Al 1-xy )O 2 ), One or more of Na 3 V 2 (PO 4 ) 2 F 3 , Na 2 FePO 4 F, natural graphite, expanded graphite, mesocarbon microbeads.
  • the electrolyte salt in the electrolyte includes one or more of a lithium salt, a sodium salt, an aluminum salt, a magnesium salt, and a zinc salt.
  • the preparation process of the battery of the present invention may include the following steps:
  • Step 1 The integrated structure of the negative electrode and the separator is prepared according to the preparation method of the second aspect of the embodiment of the present invention.
  • Step 2 preparing a positive electrode of the battery: dispersing the positive electrode active material, the conductive agent, and the binder in a suitable ratio in a suitable solvent to form a positive electrode slurry; applying the positive electrode slurry to the surface of the positive electrode current collector, drying and then cutting Cut into the required size to obtain a positive electrode;
  • Step 3 Prepare the electrolyte: weigh the appropriate amount of electrolyte salt into a certain volume of solvent, stir well, then add a certain amount of additives, stir evenly and set aside.
  • the electrolyte salt in the step 3 is one or more of a lithium salt, a sodium salt, an aluminum salt, a magnesium salt, a zinc salt and the like;
  • the solvent is one of an ester, a sulfone, an ether, a nitrile or an olefin.
  • the additive includes one or more of an organic additive such as an ester, a sulfone, an ether, a nitrile or an olefin.
  • steps 1-3 can be carried out simultaneously or in any order.
  • Step 4 Assembling the battery: stacking or winding the integrated structure of the positive electrode, the negative electrode and the separator of the battery in sequence under an inert gas or an anhydrous oxygen-free environment, and adding an appropriate amount of electrolyte to the battery. In the housing, the assembly of the battery is completed.
  • the integrated structure of the negative electrode and the diaphragm provided by the embodiment of the invention shortens the transmission distance between the positive and negative ions between the positive and negative ions, improves the transmission speed, thereby reducing the polarization phenomenon of the battery at a high magnification, so that the battery It also has considerable capacity at high magnifications;
  • the integrated structure of the negative electrode and the diaphragm can effectively reduce the production process requirements of the battery, simplify the process, reduce the production cost, and further reduce the battery quality and volume, and is beneficial to increase the capacity of the battery and the mass energy density;
  • the integrated structure of the negative electrode and the separator has excellent wettability, liquid absorption rate, and liquid retention rate, thereby enhancing the utilization rate of the electrolyte (and the liquid retention ability) of the battery.
  • the diaphragm component in the integrated structure of the negative electrode and the diaphragm is thermally stable and has good mechanical properties, thereby improving the safety performance of the battery at high temperature, avoiding the occurrence of thermal runaway, increasing the mechanical strength of the battery, and suppressing the generation of dendrites. .
  • FIG. 1 is a schematic view showing an integrated structure of a negative electrode and a separator according to Embodiment 1 of the present invention
  • FIG. 2 is a graph showing charge-discharge specific capacity and coulombic efficiency of a secondary battery according to Embodiment 1 of the present invention at different magnifications;
  • Fig. 3 is a graph showing the charge and discharge cycle performance of the secondary battery of Example 1 of the present invention at a 2C rate.
  • a method for preparing an integrated structure of a negative electrode and a separator comprises the following steps:
  • PVDF-HFP polyvinylidene fluoride-hexafluoropropylene copolymer
  • 10 mL of acetone 0.75 g were placed in a closed glass vial, heated in a water bath (50 ° C) and stirred (400 r / min) for 1 h to obtain colorless and transparent. liquid. Then, 2.5 mL of the absolute ethanol liquid was added dropwise to the glass bottle, and the mixture was stirred at 50 ° C for 0.5 h to obtain the desired polymer solution;
  • the polymer solution obtained in the step (1) is directly coated on the surface of the surface-treated aluminum foil in the step (2) by a knife coating method, solidified and dried in a vacuum drying oven (80 ° C) for 12 hours, that is, An integrated structure of the negative electrode and the separator is obtained.
  • FIG. 1 is a schematic view showing an integrated structure of a negative electrode and a separator according to Embodiment 1 of the present invention; in the figure, 10 is an aluminum foil, 11 is a concave pattern, and 20 is a porous organic polymer film.
  • FIG. 2 is a charge-discharge ratio of the secondary battery of Example 1 of the present invention at different magnifications Capacity and coulombic efficiency map; it can be seen from Fig. 2 that the obtained secondary battery has excellent rate performance.
  • the capacity retention rate is still more than 80%.
  • Fig. 3 is a graph showing the charge and discharge cycle performance of the secondary battery of Example 1 of the present invention at a 2C rate. As is apparent from Fig. 3, the obtained secondary battery has excellent cycle stability. At 2C charge and discharge rate (charge and discharge time is 30min), the capacity can still be maintained above 90% after 1000 cycles.
  • the preparation process of the secondary batteries of Examples 2-11 and Example 1 was the same except that the metal foil used in the integrated structure of the negative electrode and the separator was the same, and the materials used in the same were the same as those of Examples 2-11.
  • the secondary battery was subjected to electrochemical performance test and compared with the performance of Example 1 of the present invention.
  • the metal foils used in Examples 2-11 and their electrochemical properties are shown in Table 1.
  • Table 1 Electrochemical performance parameter tables of secondary batteries of Examples 1 to 11 of the present invention
  • the specific capacity of the battery is higher, the cycle performance is better, and the energy density is higher.
  • the preparation process of the secondary batteries of Examples 12-34 and Example 1 was the same except that the positive electrode active material and the electrolyte used in the preparation of the positive electrode of the battery were the same, and all the materials and materials used were the same, and at the same time, the two of Examples 12-34 were
  • the secondary battery was subjected to electrochemical performance test and compared with the performance of Example 1 of the present invention.
  • the positive electrode active materials used in Examples 12-34 and their electrochemical properties are detailed in Table 2.
  • Table 2 Electrochemical performance parameter tables of secondary batteries of Examples 12-34 of the present invention
  • the positive electrode material is a graphite material, LiCoO 2 , LiFePO 4 , Li(Ni x Co y Al 1-xy )O 2 ), etc.
  • the secondary battery has a higher specific capacity and a higher energy density.
  • the method for preparing the polymer solution in the step (1) is different, and the prepared porous polymer film material is different.
  • the porous polymer film material is nitrile-acetylated fiber.
  • -PVDF-HFP blend polymer the preparation process is:
  • PVDF-HFP polyvinylidene fluoride-hexafluoropropylene
  • nitrile acetylated cellulose-PVDF-HFP blend polymer precursor slurry obtained in the step (1) is directly coated on the surface of the surface-treated aluminum foil in the step (2) by a knife coating method, and after solidification molding It was dried in a vacuum drying oven (80 ° C) for 12 h to obtain an integrated structure of the negative electrode and the separator.
  • the method for preparing the polymer solution in the step (1) is different, and the prepared porous polymer film material is different.
  • the porous polymer film material is a double epoxy end.
  • PVDF-HFP and polyethyleneimine (PEI) are sequentially added to a certain amount of acetone solvent according to a certain ratio, and the two polymers are fully dissolved after stirring at room temperature for 1 hour, and then the double epoxy end group polyethylene is added.
  • the double epoxy-terminated polyethylene glycol-PVDF-HFP semi-interpenetrating network polymer precursor slurry obtained in the step (1) is directly coated by the surface treatment in the step (2) by a doctor blade method.
  • the surface of the aluminum foil was solidified and placed in a vacuum drying oven (80 ° C) for 12 hours to obtain an integrated structure of the negative electrode and the separator.
  • the secondary batteries of Examples 35-53 were subjected to electrochemical performance tests and compared with the performance of Example 1 of the present invention.
  • the electrochemical properties of the polymer materials and batteries used in Examples 35-53 are shown in Table 3. .
  • Table 3 Electrochemical performance parameter tables of secondary batteries of Examples 35-53 of the present invention
  • polyvinylidene fluoride-hexafluoropropylene is selected as the porous polymer film material, and the assembled battery has higher specific capacity, higher energy density, and greatly improved cycle performance. .
  • Example 1 The preparation process of the secondary batteries of Examples 54-56 and Example 1 was the same except that the absolute ethanol content of the polymer membrane solution was different, and all the other steps and materials used were the same, and Examples 54-56 were simultaneously carried out.
  • the secondary battery was subjected to electrochemical performance test of the battery and compared with the performance of Example 1 of the present invention. The results are shown in Table 4.
  • Table 4 Electrochemical performance parameter tables of secondary batteries of Examples 54-56 of the present invention
  • Example 1 The preparation process of the secondary batteries of Examples 57-60 and Example 1 was the same except that the metal foil was treated differently, and all the other steps and materials used were the same, and the electrochemical performance of the secondary batteries of Examples 57-60 was performed. Tested and compared with the performance of Example 1 of the present invention, the results are shown in Table 5.
  • Table 5 Electrochemical performance parameter tables of secondary batteries of Examples 57-60 of the present invention
  • the metal foil pretreatment method is better when the lateral roughening and the organic silane coupling agent (2 minutes) are combined, and the assembled battery has a larger specific capacity. High, higher energy density, and significantly improved cycle performance.
  • Example 1 The preparation process of the secondary batteries of Examples 61-63 and Example 1 was the same except that the arrangement of the porous polymer film was different, all other steps and materials used were the same, and the secondary batteries of Examples 61-63 were electrochemically treated.
  • the performance test was compared with the performance of Example 1 of the present invention, and the results are shown in Table 6.
  • the integrated structure of the negative electrode and the diaphragm provided by the embodiment of the invention can effectively reduce the volume and weight of the battery, simplify the production process, increase the overall capacity and energy density of the battery, and improve the high rate performance and high temperature performance of the battery, and solve the present problem.
  • There are problems in the secondary battery production process large initial investment, poor battery safety performance, low energy density, and difficult design and assembly.

Abstract

一种负极和隔膜一体化结构，包括金属箔片（10）和设置在所述金属箔片表面的多孔有机聚合物膜（20），所述金属箔片（10）同时充当负极集流体和负极活性材料，所述多孔有机聚合物膜（20）充当隔膜。该一体化结构可有效减小电池的体积及重量，简化生产过程，增加电池的整体容量以及能量密度，同时提高电池的高倍率性能和高温性能，解决了现有二次电池生产工艺复杂、前期投入大、电池安全性能差、能量密度低、设计组装困难等问题。还提供了该负极和隔膜一体化结构的制备方法以及包含该一体化结构的电池。

Description

一种负极和隔膜一体化结构及其制备方法和电池 技术领域
本发明涉及二次电池技术领域，特别是涉及一种负极和隔膜一体化结构及其制备方法和电池。
背景技术
目前，商用锂离子电池多用石墨类材料作为负极材料，然而，由于锂离子在石墨负极材料中的嵌入位点有限，其理论比容量只有372mAh g-1，从而限制了锂离子电池的能量密度，不能满足新型消费类电子产品、电动汽车、储能电站等的需求。隔膜则多选用多孔聚乙烯/聚丙烯类隔膜，使得电池的耐热性较差，容易发生热失控，进而引起严重的安全问题。为了使隔膜具有足够的强度，其必须具有一定的厚度下限，这就限制了电池容量的进一步提高。如果单纯的降低薄膜厚度，将会造成薄膜的局部强度不足，同时在高温下会造成形态缺陷，所以，这些薄膜厚度的降低空间是有限的。
此外，现有二次电池的生产工艺较为繁琐，包括正负极混料、涂布、辊压、制片、焊极耳、卷绕、入壳、烘干、注液、静置、封口、化成、分容等步骤，对生产厂房、自动化设备、人员熟练度要求较高，前期投入大。
发明内容
鉴于此，本发明第一方面提供了一种负极和隔膜一体化结构，该一体化设计可有效减小电池的体积及重量，简化生产过程，增加电池的整体容量以及能量密度，同时提高电池的高倍率性能和高温性能。
第一方面，本发明提供了一种负极和隔膜一体化结构，包括金属箔片和设置 在所述金属箔片表面的多孔有机聚合物膜，所述金属箔片同时充当负极集流体和负极活性材料，所述多孔有机聚合物膜充当隔膜。
本发明实施方式中，根据具体的应用情况，所述孔有机聚合物膜可以是形成在所述金属箔片的一侧表面，也可以是形成在所述金属箔片的整个表面。当形成在一侧表面时，可与正极构成一个电极单元，制作成扣式电池等；当形成在整个表面时，可与正极形成多个叠加的电极单元，制作成卷绕式商用电池等。
本发明的负极和隔膜一体化结构中，金属箔片与锂离子通过合金化-去合金化反应实现电池充放电。
所述金属箔片的材质包括钛、锰、铬、镓、镁、钒、锗、铟、铝、铜、铁、锡、镍、锌、锂中的任意一种，或含有至少一种上述金属元素的合金。金属箔片表面的一些表面态或者悬挂键，可以和多孔有机聚合物膜中的有机物聚合物产生一定的相互作用，从而两者之间具有一定的作用力。
所述金属箔片表面设置有凹形图案，所述多孔有机聚合物膜部分设置于所述凹形图案中，使所述多孔有机聚合物膜与所述金属箔片结合更紧密。所述凹形图案的具体形状不作特殊限定，可以是规则的，也可以是不规则的。所述凹形图案的凹槽深度可为0.1μm-5μm。
所述金属箔片表面修饰有含双性官能团的有机物，所述含双性官能团的有机物与所述多孔有机聚合物膜中的有机聚合物通过化学相互作用，使所述多孔有机聚合物膜与所述金属箔片紧密结合。所述含双性官能团的有机物可以是有机硅烷偶联剂、铬络合物偶联剂、钛酸酯偶联剂等。
所述多孔有机聚合物膜的材质包括聚氧化乙烯、聚甲基丙烯酸甲酯、聚偏氟乙烯-六氟丙烯、聚氧丙烯、聚乙烯醇缩醛、聚乙烯吡咯烷酮、磺脲聚合物、聚亚苯基砜磺酸聚合物、聚环氧乙烷、丁苯橡胶、聚丁二烯、聚氯乙烯、聚苯乙 烯、丙烯酸酯、壳糖酸、聚乙烯醇、聚乙烯醇缩丁醛、聚乙二醇、聚醚丙烯酸乙二醇酯、聚乙烯、聚丙烯、磷酸酯类聚合物中的一种或多种，或上述任意一种或几种聚合物的共混、共聚、接枝、梳化、超支化或交联网络物。
所述多孔有机聚合物膜的厚度为5-100μm。进一步地可为20-60μm。
本发明实施方式中，所述多孔有机聚合物膜采用热压、刮涂、旋涂或辊压的方式制备或设置在所述金属箔片表面。
第二方面，本发明提供了一种负极和隔膜一体化结构的制备方法，包括以下步骤：
取金属箔片，所述金属箔片同时充当负极集流体和负极活性材料；
取含有机聚合物或有机聚合物前驱体的浆料，将所述浆料采用刮涂或旋涂的方式涂覆在所述金属箔片表面，经固化成型后，得到多孔有机聚合物膜，即得到负极和隔膜一体化结构；
或直接取多孔有机聚合物膜，采用热压或辊压的方式将所述多孔有机聚合物膜压合到所述金属箔片表面，即得到负极和隔膜一体化结构。
其中，所述金属箔片的材质包括钛、锰、铬、镓、镁、钒、锗、铟、铝、铜、铁、锡、镍、锌、锂中的任意一种，或含有至少一种上述金属元素的合金。
所述含有机聚合物的浆料包括有机聚合物和溶剂，所述溶剂包括丙酮、N-2-甲基吡咯烷酮、四氢呋喃、甲苯、氯仿、三乙醇胺、环己烷、乙醚、碳酸甲酯等。
所述有机聚合物可以是聚氧化乙烯、聚甲基丙烯酸甲酯、聚偏氟乙烯-六氟丙烯、聚氧丙烯、聚乙烯醇缩醛、聚乙烯吡咯烷酮、磺脲聚合物、聚亚苯基砜磺酸聚合物、聚环氧乙烷、丁苯橡胶、聚丁二烯、聚氯乙烯、聚苯乙烯、丙烯酸酯、壳糖酸、聚乙烯醇、聚乙烯醇缩丁醛、聚乙二醇、聚醚丙烯酸乙二醇酯、 聚乙烯、聚丙烯、磷酸酯类聚合物中的一种或多种，或上述任意一种或几种聚合物的共混、共聚、接枝、梳化、超支化或交联网络物。所述有机聚合物前驱体即为上述有机聚合物的前驱体材料。
本发明中，所述刮涂的厚度为10-100μm，所述旋涂的速度为10-10000rpm，旋涂的时间为5-1200s。
本发明中，所述热压的温度为80-300℃，热压的压力为5-100Mpa，热压的时间为10-1200s，辊压的压力为50-150Mpa。
为了使金属箔片与多孔有机聚合物膜更好地结合在一起形成一体化结构，本发明中，在制备或设置所述多孔有机聚合物膜之前，先在所述金属箔片表面设置凹形图案。凹形图案可以采用磨砂、模压、激光刻蚀或化学刻蚀的方法制备得到。所述凹形图案的具体形状不作特殊限定，可以是规则的，也可以是不规则的。所述凹形图案的凹槽深度可为0.1μm-5μm。
同样地，为了增强金属箔片与多孔有机聚合物膜的结合，本发明中，在制备或设置所述多孔有机聚合物膜之前，先在所述金属箔片表面修饰含双性官能团的有机物。具体操作为：将所述金属箔片浸泡在含双性官能团的有机物的溶液中，完成表面修饰。当然，本发明中，也可在设置凹形图案后，进一步在设置有凹形图案的金属箔片表面修饰含双性官能团的有机物。所述含双性官能团的有机物可以是有机硅烷偶联剂、铬络合物偶联剂、钛酸酯偶联剂等。
第三方面，本发明提供了一种电池，包括正极，电解液，以及如本发明第一方面所述的负极和隔膜一体化结构，所述正极包括正极集流体和设置在所述正极集流体上的正极活性材料层，所述正极活性材料层包括正极活性材料。所述正极靠近所述负极和隔膜一体化结构的多孔有机聚合物膜一侧。
所述正极材料包括LiCoO2、LiMnO2、LiNiO2、LiFeO2、LiFePO4、 (Li(NixCoyMn1-x-y)O2、Li(NixCoyAl1-x-y)O2)、Na3V2(PO4)2F3、Na2FePO4F、天然石墨、膨胀石墨、中间相碳微球中的一种或多种。
所述电解液中的电解质盐包括锂盐、钠盐、铝盐、镁盐和锌盐中的一种或多种。
本发明电池的制备过程可以包括如下步骤：
步骤1、按本发明实施例第二方面所述的制备方法制得负极和隔膜一体化结构；
步骤2、制备电池正极：将正极活性材料、导电剂、粘结剂按照合适比例分散于适当溶剂中，配置成正极浆料；将所述正极浆料涂覆于正极集流体表面，干燥后裁切成所需尺寸，得到正极；
步骤3、配制电解液：称取适量电解质盐加入到一定体积溶剂中，充分搅拌溶解后，再选择性加入一定量添加剂，搅拌均匀后备用。
步骤3中所述电解质盐为锂盐、钠盐、铝盐、镁盐、锌盐等中的一种或几种；溶剂为酯类、砜类、醚类、腈类、烯烃类中的一种或几种；添加剂包括酯类、砜类、醚类、腈类或烯烃类有机添加剂中的一种或几种。
步骤1-3的制备可以同时或者按照任意顺序执行。
步骤4、组装电池：在惰性气体或无水无氧环境下，将所述电池正极、负极和隔膜一体化结构依次堆叠或卷绕成电芯，滴加适量电解液，并封装于所述电池壳体内，完成电池的组装。
实施本发明实施例，具有如下有益效果：
(1)本发明实施例提供的负极和隔膜一体化结构，缩短了正负离子在正负极之间的传输距离，提高了传输速度，从而减轻了电池在高倍率下的极化现象，使得电池在高倍率下也具有可观的容量；
(2)负极和隔膜一体化结构可有效降低电池的生产工艺要求，简化工艺，降低生产成本；也可进一步减少电池质量及体积，有利于提高电池的容量以及质量能量密度；
(3)负极和隔膜一体化结构具有优异的润湿率、吸液率、保液率，从而可增强电池对电解液的利用率(以及保液能力)。
(4)负极和隔膜一体化结构中的隔膜成分热稳定好、机械性能好，从而可提高电池在高温下的安全性能，避免热失控的产生，同时增加电池的机械强度，抑制枝晶的产生。
本发明的优点将会在下面的说明书中部分阐明，一部分根据说明书是显而易见的，或者可以通过本发明实施例的实施而获知。
附图说明
图1为本发明实施例1提供的负极和隔膜一体化结构的示意图；
图2为本发明实施例1的二次电池在不同倍率下的充放电比容量及库伦效率图；
图3为本发明实施例1的二次电池在2C倍率下的充放电循环性能图。
具体实施方式
以下所述是本发明实施例的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明实施例原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也视为本发明实施例的保护范围。
下面分多个实施例对本发明实施例进行进一步的说明。
实施例1
一种负极和隔膜一体化结构的制备方法，包括以下步骤：
(1)将0.75g聚偏氟乙烯-六氟丙烯共聚物(PVDF-HFP)以及10mL丙酮装入密闭玻璃小瓶中，水浴加热(50℃)且搅拌(400r/min)1h后得到无色透明液体。然后，将2.5mL的无水乙醇液体逐滴加入到玻璃瓶中，同样在50℃条件下搅拌0.5h得到所需聚合物溶液；
(2)取厚度为19μm的铝箔作负极活性物质以及负极集流体，采用6000目砂纸对其进行横向粗化处理，在铝箔表面形成凹形图案，然后用丙酮以及酒精超声清洗干净后放入有机硅烷偶联剂中浸泡2分钟，并用压缩空气吹干备用；
(3)将步骤(1)所得聚合物溶液用刮涂的方法直接涂覆在步骤(2)中经表面处理的铝箔表面，凝固成型后放入真空干燥箱(80℃)中干燥12h，即得到负极和隔膜一体化结构。
图1为本发明实施例1提供的负极和隔膜一体化结构的示意图；图中，10为铝箔，11为凹形图案，20为多孔有机聚合物膜。
二次电池的制备
(1)制备电池正极：将0.8g天然石墨、0.1g导电碳黑、0.1g聚偏氟乙烯加入到4mL氮甲基吡咯烷酮溶剂中，充分研磨获得均匀浆料；然后将浆料均匀涂覆于铝箔表面，80℃真空干燥12h，得到正极；
(2)配制电解液：配制4mol/L的LiPF6的碳酸甲乙酯溶液(EMC)，并加入2wt％的碳酸亚乙烯酯(VC)作为电解液备用；
(3)二次电池组装：在氩气保护的手套箱中，将上述制备好的电池正极、负极和隔膜一体化结构依次排放、卷绕，再经过电解液注入、封口等工艺完成二次电池组装。
对本发明实施例1的二次电池进行电化学性能测试，充放电速率：2C(30 min充放电)，测试温度：25℃，截止电压：3-4.95V，测试结果如图2和图3所示，图2为本发明实施例1的二次电池在不同倍率下的充放电比容量及库伦效率图；从图2可获知，所获得二次电池具有优异的倍率性能。在10C充放电速率下(6分钟充放电)，容量保持率仍有80％以上。
图3为本发明实施例1的二次电池在2C倍率下的充放电循环性能图。从图3可获知，所获得二次电池具有优异的循环稳定性。在2C充放电速率下(充放电时间为30min)，1000次循环后容量仍可以保持90％以上。
实施例2-11
实施例2-11与实施例1的二次电池制备过程除负极和隔膜一体化结构中使用的金属箔材不同以外，其他所有步骤及使用的材料都相同，同时对实施例2-11的二次电池进行电化学性能测试，并与本发明实施例1的性能进行比较，实施例2-11所使用的金属箔材及其电化学性能具体参见表1。
表1：本发明实施例1-11的二次电池的电化学性能参数表
Figure PCTCN2017078207-appb-000001
从表1可以看出，本发明实施例中，负极选用铝箔时，电池比容量更高，循环性能更好，能量密度更高。
实施例12-34
实施例12-34与实施例1的二次电池制备过程除制备电池正极时使用的正极活性材料和电解液不同以外，其他所有步骤及使用的材料都相同，同时对实施例12-34的二次电池进行电化学性能测试，并与本发明实施例1的性能进行比较，实施例12-34所使用的正极活性材料及其电化学性能具体参见表2。
表2：本发明实施例12-34的二次电池的电化学性能参数表
Figure PCTCN2017078207-appb-000002
Figure PCTCN2017078207-appb-000003
从表2中可以看出，本发明实施例中，正极材料为石墨类材料、LiCoO2、LiFePO4、Li(NixCoyAl1-x-y)O2)等材料时，其所组装得到的二次电池比容量更高，能量密度更高。
实施例35-51
实施例35-51与实施例1的二次电池制备过程，除步骤(1)中制备聚合物溶液时使用的聚合物材料不同以外，其他所有步骤及使用的材料都相同。
实施例52
与实施例1的区别仅在于，步骤(1)中制备聚合物溶液的方法不同，制备得到的多孔聚合物膜材料不同，具体地，本实施例中，多孔聚合物膜材料为腈乙化纤维素-PVDF-HFP共混聚合物，制备过程为：
(1)把重量比为1:1的腈乙化纤维素和聚偏氟乙烯-六氟丙烯(PVDF-HFP)溶于丙酮溶剂中，室温下磁力搅拌使两种聚合物充分溶解，然后加入一定量的乙醇，静置30min脱去气泡，即可得到腈乙化纤维素-PVDF-HFP共混聚合物前驱体浆料；
(2)取厚度为19μm的铝箔作负极活性物质以及负极集流体，采用6000目砂纸对其进行横向粗化处理，在铝箔表面形成凹形图案，然后用丙酮以及酒精超声清洗干净后放入有机硅烷偶联剂中浸泡2分钟，并用压缩空气吹干备用；
(3)将步骤(1)所得腈乙化纤维素-PVDF-HFP共混聚合物前驱体浆料用刮涂的方法直接涂覆在步骤(2)中经表面处理的铝箔表面，凝固成型后放入真空干燥箱(80℃)中干燥12h，即得到负极和隔膜一体化结构。
实施例53
与实施例1的区别仅在于，步骤(1)中制备聚合物溶液的方法不同，制备得到的多孔聚合物膜材料不同，具体地，本实施例中，多孔聚合物膜材料为双环氧端基聚乙二醇-PVDF-HFP的半互穿网络聚合物，制备过程为：
(1)按一定配比将PVDF-HFP和聚乙烯亚胺(PEI)依次加入一定质量的丙酮溶剂中，室温下搅拌1h使两种聚合物充分溶解，然后加入双环氧端基聚乙二醇，搅拌1h形成均匀溶液，再加入一定量的乙醇，静置30min以上脱去气泡，得到双环氧端基聚乙二醇-PVDF-HFP半互穿网络聚合物前驱体浆料；
(2)取厚度为19μm的铝箔作负极活性物质以及负极集流体，采用6000目砂纸对其进行横向粗化处理，在铝箔表面形成凹形图案，然后用丙酮以及酒 精超声清洗干净后放入有机硅烷偶联剂中浸泡2分钟，并用压缩空气吹干备用；
(3)将步骤(1)所得双环氧端基聚乙二醇-PVDF-HFP半互穿网络聚合物前驱体浆料用刮涂的方法直接涂覆在步骤(2)中经表面处理的铝箔表面，凝固成型后放入真空干燥箱(80℃)中干燥12h，即得到负极和隔膜一体化结构。
将实施例35-53的二次电池进行电化学性能测试，并与本发明实施例1的性能进行比较，实施例35-53所使用的聚合物材料及电池电化学性能具体如表3所示。
表3：本发明实施例35-53的二次电池的电化学性能参数表
Figure PCTCN2017078207-appb-000004
Figure PCTCN2017078207-appb-000005
从表3中可以看出，本发明实施例中，选用聚偏氟乙烯-六氟丙烯作为多孔聚合物膜材料，其所组装得到的电池比容量更高，能量密度更高，循环性能大幅提升。
实施例54-56
实施例54-56与实施例1的二次电池制备过程除制备聚合物隔膜溶液时所滴加的无水乙醇含量不同以外，其他所有步骤及使用的材料都相同，同时对实施例54-56的二次电池进行电池的电化学性能测试，并与本发明实施例1的性能进行比较，结果参见表4。
表4：本发明实施例54-56的二次电池的电化学性能参数表
Figure PCTCN2017078207-appb-000006
实施例57-60
实施例57-60与实施例1的二次电池制备过程除金属箔片前处理方式不同以外，其他所有步骤及使用的材料都相同，同时对实施例57-60的二次电池进行电化学性能测试，并与本发明实施例1的性能进行比较，结果参见表5。
表5：本发明实施例57-60的二次电池的电化学性能参数表
Figure PCTCN2017078207-appb-000007
从表5中可以看出，本发明实施例中，金属箔片前处理方式为横向粗化和有机硅烷偶联剂(2分钟)相结合时效果更好，其所组装得到的电池比容量更高，能量密度更高，循环性能大幅提升。
实施例61-63
实施例61-63与实施例1的二次电池制备过程除多孔聚合物膜的设置方式不同以外，其他所有步骤及使用的材料都相同，同时对实施例61-63的二次电池进行电化学性能测试，并与本发明实施例1的性能进行比较，结果参见表6。
表6：本发明实施例61-63的二次电池的电化学性能参数表
Figure PCTCN2017078207-appb-000008
从表6中可以看出，本发明实施例中，采用刮涂方式将多孔聚合物膜制备结合在金属箔片表面时，其性能良好且节约生产成本。
本发明实施例提供的负极和隔膜一体化结构，可有效减小电池的体积及重量，简化生产过程，增加电池的整体容量以及能量密度，同时提高电池的高倍率性能和高温性能，解决了现有二次电池生产工艺复杂、前期投入大、电池安全性能差、能量密度低、设计组装困难等问题。

Claims (13)

  1. 一种负极和隔膜一体化结构，其特征在于，包括金属箔片和设置在所述金属箔片表面的多孔有机聚合物膜，所述金属箔片同时充当负极集流体和负极活性材料，所述多孔有机聚合物膜充当隔膜。
  2. 如权利要求1所述的负极和隔膜一体化结构，其特征在于，所述金属箔片的材质包括钛、锰、铬、镓、镁、钒、锗、铟、铝、铜、铁、锡、镍、锌、锂中的任意一种，或含有至少一种上述金属元素的合金。
  3. 如权利要求1所述的负极和隔膜一体化结构，其特征在于，所述多孔有机聚合物膜的材质包括聚氧化乙烯、聚甲基丙烯酸甲酯、聚偏氟乙烯-六氟丙烯、聚氧丙烯、聚乙烯醇缩醛、聚乙烯吡咯烷酮、磺脲聚合物、聚亚苯基砜磺酸聚合物、聚环氧乙烷、丁苯橡胶、聚丁二烯、聚氯乙烯、聚苯乙烯、丙烯酸酯、壳糖酸、聚乙烯醇、聚乙烯醇缩丁醛、聚乙二醇、聚醚丙烯酸乙二醇酯、聚乙烯、聚丙烯、磷酸酯类聚合物中的一种或多种，或上述任意一种或几种聚合物的共混、共聚、接枝、梳化、超支化或交联网络物；所述多孔有机聚合物膜的厚度为5-100μm。
  4. 如权利要求1所述的负极和隔膜一体化结构，其特征在于，所述金属箔片表面设置有凹形图案，所述多孔有机聚合物膜部分设置于所述凹形图案中，从而与所述金属箔片紧密结合。
  5. 如权利要求1所述的负极和隔膜一体化结构，其特征在于，所述金属箔片表面修饰有含双性官能团的有机物，所述含双性官能团的有机物与所述多孔有机聚合物膜中的有机聚合物通过化学相互作用，使所述多孔有机聚合物膜与所述金属箔片紧密结合。
  6. 如权利要求5所述的负极和隔膜一体化结构，其特征在于，所述含双性官能团的有机物包括有机硅烷偶联剂、铬络合物偶联剂、钛酸酯偶联剂中的至少一种。
  7. 如权利要求1所述的负极和隔膜一体化结构，其特征在于，所述多孔有机聚合物膜采用热压、刮涂、旋涂或辊压的方式制备或设置在所述金属箔片表面。
  8. 一种负极和隔膜一体化结构的制备方法，其特征在于，包括以下步骤：
    取金属箔片，所述金属箔片同时充当负极集流体和负极活性材料；
    取含有机聚合物或有机聚合物前驱体的浆料，将所述浆料采用刮涂或旋涂的方式涂覆在所述金属箔片表面，经固化成型后，得到多孔有机聚合物膜，即得到负极和隔膜一体化结构；
    或直接取多孔有机聚合物膜，采用热压或辊压的方式将所述多孔有机聚合物膜压合到所述金属箔片表面，即得到负极和隔膜一体化结构。
  9. 如权利要求8所述的负极和隔膜一体化结构的制备方法，其特征在于，在制备或设置所述多孔有机聚合物膜之前，先采用磨砂、模压、激光刻蚀或化学刻蚀的方法在所述金属箔片表面设置凹形图案。
  10. 如权利要求8所述的负极和隔膜一体化结构的制备方法，其特征在于，在制备或设置所述多孔有机聚合物膜之前，先在所述金属箔片表面修饰含双性官能团的有机物。
  11. 一种电池，其特征在于，包括正极，电解液，以及如权利要求1-7任一项所述的负极和隔膜一体化结构，所述正极包括正极集流体和设置在所述正极集流体上的正极活性材料层，所述正极活性材料层包括正极活性材料。
  12. 如权利要求11所述的电池，其特征在于，所述正极材料包括LiCoO2、 LiMnO2、LiNiO2、LiFeO2、LiFePO4、(Li(NixCoyMn1-x-y)O2、Li(NixCoyAl1-x-y)O2)、Na3V2(PO4)2F3、Na2FePO4F、天然石墨、膨胀石墨、中间相碳微球中的一种或多种。
  13. 如权利要求11所述的电池，其特征在于，所述电解液中的电解质盐包括锂盐、钠盐、铝盐、镁盐和锌盐中的一种或多种。
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CN103247819A (zh) * 2012-02-06 2013-08-14 三星Sdi株式会社 锂二次电池
CN104600365A (zh) * 2014-12-23 2015-05-06 中国兵器工业第二一三研究所 超薄型锂锰电池的一体化结构
CN105074989A (zh) * 2013-10-31 2015-11-18 株式会社Lg化学 电极-隔膜复合物的制造方法、由该制造方法制造的电极-隔膜复合物及包含其的锂二次电池
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CN105074989A (zh) * 2013-10-31 2015-11-18 株式会社Lg化学 电极-隔膜复合物的制造方法、由该制造方法制造的电极-隔膜复合物及包含其的锂二次电池
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