WO2023151400A1 - 一种复合集流体、制备方法及锂离子电池 - Google Patents

一种复合集流体、制备方法及锂离子电池 Download PDF

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WO2023151400A1
WO2023151400A1 PCT/CN2022/141266 CN2022141266W WO2023151400A1 WO 2023151400 A1 WO2023151400 A1 WO 2023151400A1 CN 2022141266 W CN2022141266 W CN 2022141266W WO 2023151400 A1 WO2023151400 A1 WO 2023151400A1
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current collector
lithium
composite current
layer
conductive
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PCT/CN2022/141266
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English (en)
French (fr)
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刘晓蕾
李黎黎
闫晟睿
高天一
胡景博
高华文
姜涛
孙焕丽
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中国第一汽车股份有限公司
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Publication of WO2023151400A1 publication Critical patent/WO2023151400A1/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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/665—Composites
    • H01M4/667—Composites in the form of layers, e.g. coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H01M4/80—Porous plates, e.g. sintered carriers
    • 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 technical field of lithium ion batteries, and in particular relates to a composite current collector, a preparation method and a lithium ion battery.
  • Lithium-ion batteries have been widely used due to their excellent performance indicators, especially good cycle life, high working voltage, no memory effect and less pollution. Including all kinds of power tools, electric vehicles and large energy storage power systems and other different fields.
  • the prior art discloses a multilayer material comprising a solid substrate and at least two superimposed solid layers containing particles of an electrochemically active material, the first solid layer being attached to the substrate and the second solid layer attached to the first solid layer.
  • the multilayer material has a constant thickness of the upper layer of not less than 95% and a penetration depth of the second solid layer into the first solid layer which is less than 10% of the first solid layer and can be prepared as an electrode component with a low Generators of supercomposite degradation risks.
  • the current collector layer has not been adjusted, and there are electrochemically active positive or negative electrode materials as multi-layer materials, although the multi-layer matching is carried out by using materials with high energy density and low energy density, it is necessary to compare the energy density.
  • the present invention not only reduces the weight of the current collector, but at the same time, the active material of the lithium-ion battery can adopt a high-energy density system, and the safety of the lithium-ion battery can be improved through heat-sensitive materials, that is, high-energy Double improvement of density and safety.
  • the prior art also discloses a current collector, its pole pieces and a battery.
  • the applied current collector includes an insulating layer and a conductive layer, the insulating layer is used to carry the conductive layer; the conductive layer is used to carry the electrode active material layer, the conductive layer is located on at least one surface of the insulating layer, the thickness of the conductive layer is D2, and D2 satisfies : 300nm ⁇ D2 ⁇ 2 ⁇ m, the current collector further includes a protective layer disposed on at least one surface of the conductive layer. Its current collector can improve the short-circuit resistance when the battery is short-circuited under abnormal conditions, greatly reduce the short-circuit current, greatly reduce the heat generated by the short-circuit, and improve the safety performance of the battery.
  • the protective layer can increase the mechanical strength of the conductive layer and further improve The safety performance of the battery can also prevent the conductive layer from being damaged, or oxidation, corrosion, etc., and significantly improve the working stability and service life of the current collector.
  • the conductive layer needs to form a good contact interface with the insulating layer, if mechanical rolling is adopted, there are high requirements for the thickness and strength of the insulating layer, and it is difficult to ensure the thickness control of the composite current collector; if adopting In the way of glue bonding, there are not many kinds of glue that can be selected, and at the same time, high temperature or long-term standing is required to achieve the bonding effect, and the production efficiency is not high; if the vacuum evaporation method is adopted, a composite current collector with good performance can be obtained, but The high cost of equipment and technology is not conducive to wide application.
  • the object of the present invention is to address the above-mentioned deficiencies in the prior art, provide a composite current collector, and also provide a preparation method of the composite current collector and a lithium-ion battery, so as to solve the problem of dual promotion of high energy density and safety.
  • the energy density and safety of lithium-ion batteries are further improved through lightweight technology combined with a composite current collector of a lithium supplementary layer and a conductive thermal material layer.
  • a composite current collector which is composed of a porous foil, a lithium supplementary layer, and a conductive safety layer of a heat-sensitive material;
  • the porous foil is made of a metal conductive material or a carbon-based conductive material, and the porosity of the material is 0% to 60%.
  • the lithium supplementary layer is made of lithium metal material or lithium metal compound material;
  • the material of the conductive safety layer of the heat-sensitive material is composed of a material with a positive temperature coefficient, a conductive material and an adhesive.
  • the metal conductive material is preferably copper, aluminum, nickel, titanium;
  • the carbon-based conductive material is preferably hard carbon, soft carbon, graphite, acetylene black, graphene, and carbon nanotubes.
  • the thickness of the composite current collector is 5um-25um
  • the thickness of the porous foil material is 4um-20um
  • the thickness of the lithium supplementary layer material is 5um-15um
  • the thickness of the conductive safety layer of the heat-sensitive material is 3um-15um.
  • the metal lithium chemical material that can be used for the positive part of the lithium-replenishing layer is preferably a lithium-rich compound, or a nanocomposite material based on a conversion reaction
  • the metal lithium that can be used for the negative part of the lithium-replenishing layer is preferably metal lithium strips, stabilized lithium metal powder, Lithium silicide powder.
  • the positive temperature coefficient material is a polymer material, preferably high-density polyethylene, polyvinylidene fluoride, carboxylic acid-modified polyvinylidene fluoride, acrylic acid-modified polyvinylidene fluoride, polyvinylidene chloride , carboxylic acid modified polyvinylidene chloride, acrylic acid modified polyvinylidene chloride, polyvinylidene fluoride copolymer, polyvinylidene chloride copolymer materials; it can also be expandable graphite materials, preferably granular, medium Expandable graphite at the initial expansion temperature.
  • the wt% of the positive temperature coefficient material is 75%-90%
  • the wt% of the conductive material is 5%-15%
  • the wt% of the adhesive material is 5%-15%.
  • the conductive material is one of metal conductive materials and carbon-based conductive materials, and the metal conductive materials are preferably copper, aluminum, nickel, titanium metal particle materials; the carbon-based conductive materials are preferably hard carbon, soft carbon, Graphite, acetylene black, graphene, carbon nanotube materials.
  • the adhesive is preferably polyacrylate, polycarbonate, polyethylene oxide, rubber, polyurethane, sodium carboxymethylcellulose, polyacrylic acid, gelatin, chitosan, hydroxyl derivatives of cyclodextrin Material.
  • a preparation method of a composite current collector comprising the following steps:
  • Porous foils are formed by dense drilling or electrodeposition
  • a lithium-ion battery including a positive pole piece, a diaphragm and a negative pole piece, wherein the current collectors of the positive pole piece and the negative pole piece can be a composite current collector, and an active material is coated on both sides of the composite current collector to prepare a positive electrode
  • the pole piece and the negative pole piece can be directly applied to the battery.
  • the thickness of the aluminum foil current collector of the positive electrode material and the copper foil current collector of the negative electrode can be reduced by 30% compared with the existing materials.
  • Composite treatment of the substrate with physical and chemical techniques can further increase the porosity to 50%;
  • the lithium supplement layer that can cover the surface and pores with lithium metal or lithium metal compound can be used for supplementing lithium when the negative electrode material containing silicon is formed for the first time, so as to achieve the effect of improving the initial efficiency of the negative electrode active material, and further Provide new solutions for improving the energy density of lithium-ion batteries;
  • FIG. 1 Schematic diagram of current collectors with different porosities
  • Figure 3 is a schematic diagram of an electrode fabricated using a composite current collector.
  • the composite current collector of the present invention consists of a lightweight designed porous foil (mark 3 in Figure 2), a lithium supplementary layer (mark 2, 4 in Figure 2), and a conductive safety layer of heat-sensitive material (mark 1 and 5 in Figure 2) Composition, the thickness is 5um ⁇ 25um, as shown in Figure 2.
  • the design of the material, porosity and thickness of the composite current collector needs to meet a certain mechanical strength. If the strength is too weak, it cannot meet the composite process of the conductive safety protection layer of heat-sensitive materials. If it is too strong, there will be design redundancy.
  • the porous foil material is one of metal conductive materials and carbon-based conductive materials; the metal conductive materials are preferably copper, aluminum, nickel, titanium, etc.; the carbon-based conductive materials are preferably hard carbon, soft carbon, graphite, Acetylene black, graphene, carbon nanotubes, etc.
  • the porosity of the porous foil material is 0%-60%, as shown in FIG. 1 .
  • the thickness of the porous foil material is 4um-20um.
  • the lithium-replenishing layer is made of lithium metal material or lithium metal compound material
  • the metal lithium chemical material that can be used for the lithium-replenishing layer of the positive electrode is preferably a lithium-rich compound, such as Li 2 NiO 2 , Li 2 NiCuO 2 , etc., or based on Nano-composite materials for conversion reactions, such as Nano-M/LiF, Nano-M/LiO, etc., where M can be Co, Ni, and Fe elements; it can be used for the lithium supplementary layer of the negative electrode, preferably metal lithium strips, stabilized lithium metal powder (SLMP), lithium silicide powder, etc.
  • SLMP stabilized lithium metal powder
  • the thickness of the lithium-supplementing layer material is 5um-15um.
  • the material of the conductive safety layer in the heat-sensitive material layer is composed of a material with a positive temperature coefficient, a conductive material and an adhesive.
  • the positive temperature coefficient material can be a polymer material, preferably high-density polyethylene, polyvinylidene fluoride, polyvinylidene fluoride modified by carboxylic acid, polyvinylidene fluoride modified by acrylic acid, polyvinylidene chloride, carboxylate Acid-modified polyvinylidene chloride, acrylic acid-modified polyvinylidene chloride, polyvinylidene fluoride copolymer, polyvinylidene chloride copolymer materials, etc.; can also be expandable graphite materials, preferably granular, medium initial Expandable graphite at the expansion temperature.
  • the wt% of the positive temperature coefficient material is 75%-90%.
  • the conductive material is one of metal conductive materials and carbon-based conductive materials.
  • the metal conductive materials are preferably copper, aluminum, nickel, titanium metal particle materials, etc.;
  • the carbon-based conductive materials are preferably hard carbon, soft carbon, graphite, Acetylene black, graphene, carbon nanotube materials, etc.
  • the wt% of the conductive material is 5%-15%.
  • the adhesive is preferably polyacrylate, polycarbonate, polyethylene oxide, rubber, polyurethane, sodium carboxymethylcellulose, polyacrylic acid, gelatin, chitosan, hydroxyl derivative materials of cyclodextrin, and the like.
  • the wt% of the adhesive material is 5%-15%.
  • the conductive safety layer of the heat-sensitive material has a thickness of 3um-15um.
  • the composite current collector can realize the compounding of the current collector and the conductive safety layer of the heat-sensitive material by coating method or dip coating method, and the coating method is preferably roll coating, extrusion coating, doctor blade coating, gravure coating and the like.
  • a preparation method of a composite current collector comprising the following steps:
  • Porous foils are formed by dense drilling or electrodeposition
  • This embodiment also provides the use of a lithium-ion battery, including a positive pole piece, a separator, and a negative pole piece, wherein the current collectors of the positive pole piece and the negative pole piece can be selected from a composite current collector (identification 2-3-4 in Figure 3 -5-6), as shown in Figure 3, the active material is coated on both sides of the safe composite current collector (marks 1 and 7 in Figure 3), and the positive electrode sheet and the negative electrode sheet are prepared and can be directly applied to the battery.
  • a lithium-ion battery including a positive pole piece, a separator, and a negative pole piece, wherein the current collectors of the positive pole piece and the negative pole piece can be selected from a composite current collector (identification 2-3-4 in Figure 3 -5-6), as shown in Figure 3, the active material is coated on both sides of the safe composite current collector (marks 1 and 7 in Figure 3), and the positive electrode sheet and the negative electrode sheet are prepared and can be directly applied to the battery.
  • the battery of the present application can be wound type or laminated type.
  • the battery of the present application may be one of a lithium ion secondary battery, a lithium primary battery, a sodium ion battery, and a magnesium ion battery. But it is not limited to this.
  • Positive electrode sheet use ternary materials NCM811 (LiNi0.8Co0.1Mn0.1O2), SP and PVDF, use NMP as solvent, stir evenly at the ratio of 95%: 2%: 3%, and then coat it on the current collector.
  • the current collector is an aluminum substrate safety composite current collector prepared according to the above method and a conventional 12um aluminum foil, which is used as the positive electrode active material layer. After drying at 85°C, it is cold-pressed, and then trimmed, cut into pieces, and divided into strips. Then dry it under vacuum condition at 85° C. for 4 hours, and weld the tabs to make a positive pole piece.
  • Negative electrode sheet use graphite, SP, CMC, SBR, use deionized water as solvent, stir evenly at the ratio of 96.5%: 1%: 1%: 1.5%, and then coat it on the current collector.
  • the copper-based safety composite current collector prepared by the above method and the conventional 8um copper foil are used as the negative electrode active material layer, dried at 85°C and then cold-pressed, then edge trimmed, cut into pieces, and stripped, and then heated at 85°C Dry it under vacuum for 4 hours, weld the tabs, and make negative pole pieces.
  • the positive electrode sheet (compacted density: 3.4g/cm3), PP/PE/PP separator and negative electrode sheet (compacted density: 1.6g/cm3) are wound together into a
  • the bare cell is then put into the battery case, and the electrolyte solution (EC:EMC volume ratio is 3:7, LiPF6 is 1mol/L) is injected, followed by sealing, forming and other processes, and finally a lithium-ion battery is obtained, as shown in the table 1.
  • Acupuncture test is used to compare the battery safety performance.
  • the secondary battery is fully charged with a current of 1C to the charging cut-off voltage, and then charged at a constant voltage until the current drops to 0.05C, and the charging is stopped.
  • the high-temperature-resistant steel needle used (the cone angle of the needle tip is 45°) penetrates from the direction perpendicular to the battery plate at a speed of 25mm/s, and the penetration position is close to the geometric center of the pierced surface. The steel needle stays in the battery. Observe whether the battery is burning or exploding.
  • Cycle test use 0.3C to charge to the cut-off voltage, then charge at constant voltage until the current drops to 0.05C, stop charging, let it stand for 5 minutes, then discharge to 1C to cut-off voltage, cycle to 1000 cycles according to this procedure, and use the discharge capacity as the capacity Retention rate calculation standard.
  • the current collectors involved in the present invention are metal aluminum foil and metal copper foil used in the positive and negative electrodes of lithium-ion batteries.
  • the foil manufacturing process it can be realized by dense drilling or electrodeposition to form microporous foils, etc. to make porous
  • the process of metal foil is mature first, and foil materials with different porosity can be selected according to the needs, and then the type and thickness of metal lithium or lithium metal compound and conductive coating can be determined according to the thickness and porosity of the metal foil, and finally in the preparation Coating of active materials on the composite current collector.
  • the composite current collector of the present invention includes a lightweight designed porous metal foil, lithium metal or lithium metal compound, and a conductive safety protection layer with heat-sensitive properties.
  • the metal The porosity of the foil is designed to increase the energy density of lithium-ion batteries.
  • lithium metal or lithium metal compounds can be used to supplement lithium when using silicon-containing negative electrode materials during the first formation, so as to achieve the effect of improving the first efficiency of negative electrode active materials, and further provide new opportunities for improving the energy density of lithium-ion batteries.
  • the large current will cause the temperature of the heat-sensitive material matrix material to rise rapidly to the melting temperature of the polymer, and the volume will expand rapidly and accompany the crystal phase to the amorphous phase.
  • the conductive filler migrates and diffuses in the matrix and disperses in the entire volume, a large number of conductive chains are destroyed, and the sharp increase in resistance makes the loop current rapidly decrease, which can quickly cut off the conductive network and absorb part of the flammable electrolyte at the same time, reducing the battery life. Generate heat, thereby improving the safety performance of the battery.

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Abstract

本发明提供一种复合集流体、制备方法及锂离子电池，复合集流体由多孔箔材、补锂层及热敏性材料的导电安全层组成，制备方法包括形成多孔箔材；根据多孔箔材的厚度及孔隙率来确定多孔箔材、补锂层及热敏性材料的导电安全层的材料种类与厚度；通过涂布法、浸涂法实现集流体和热敏性材料的导电安全层的复合，在制备的复合集流体上进行活性材料的涂覆；锂离子电池包括正极极片、隔膜和负极极片，正极极片、负极极片的集流体可选用复合集流体，在复合集流体的双面涂覆活性物质，制得极片可直接应用于电池中。本发明通过造孔实现金属集流体的轻量化，提升负极活性材料的首次效率及锂离子电池的能量密度，减轻甚至避免锂离子电池的热扩散带来的巨大危害。

Description

一种复合集流体、制备方法及锂离子电池 技术领域
本发明属于锂离子电池技术领域，具体涉及一种复合集流体、制备方法及锂离子电池。
背景技术
锂离子电池由于其各项优异的性能指标，特别是具有良好的循环寿命、较高的工作电压、无记忆效应以及较少的污染等特性，得到了广泛的应用。包括各类电动工具、电动车及大型储能电源系统等不同领域。
近年来新能源市场不断发展成熟，电动汽车的渗透率在2021年已经达到了10％以上，同时用户对整车的续航要求也在不断提升。2021年乘用车的续驶里程普遍达到了500km以上，这就意味着对高能量密度的锂离子电池需求量显著提高。但能量密度的不断升高往往意味了其安全性会有不同程度的降低，为了解决这一相互矛盾的课题，需要从锂离子电池的结构及材料角度进行综合性的创新设计，特别是在集流体方面设计创新。
现有技术公开了一种多层材料，包括一个固体基体和至少两个重叠的固体层，这些固体层含有电化学活性材料的颗粒，第一固体层附着于附体基体上而第二固体层附着于第一固体层上。所述多层材料具有上部层不少于95％的恒定厚度以及第二固体层进入第一固体层的一个渗透深度，该深度小于第一固体层的10％，并且作为电极成分能够制备具有低超复合降解风险的发生器。但是由 于集流体层未做调整，同时作为多层材料均有具有电化学活性的正极或负极材料，虽然通过采用高能量密度和低能量密度的材料进行多层搭配，但需要对能量密度进行较大牺牲才有可能实现安全性的提升，甚至对安全性的提升的贡献几乎为零。相比于此方案，本发明不仅对集流体进行了轻量化处理，同时锂离子电池的活性材料可采用高能量密度体系，可通过热敏性材料实现锂离子电池安全性的提升，即实现了高能量密度和安全性的双重提升。
现有技术还公开了一种集流体，其极片和电池。所申请的集流体包括绝缘层和导电层，绝缘层用于承载导电层；导电层用于承载电极活性材料层，导电层位于绝缘层的至少一个表面上，导电层的厚度为D2，D2满足：300nm≤D2≤2μm，集流体还包括设置于导电层的至少一个表面上的保护层。其集流体可提高电池异常情况下发生短路时的短路电阻，使短路电流大幅度减小，极大地降低短路产热量，改善电池的安全性能，同时保护层可以提高导电层的机械强度，进一步提高电池的安全性能，同时还可以防止导电层被破坏，或者发生氧化、腐蚀等现象，显著改善集流体的工作稳定性和使用寿命。但是由于其的工艺复杂而昂贵，因为导电层需要与绝缘层形成良好接触界面，如果采取机械辊压方式，对绝缘层厚度及强度有较高要求，难以保证复合集流体的厚度控制；如果采取胶水粘接的方式，可选用的胶水种类不多，同时需要高温或长时间静置以实现粘接效果，生产效率不高；如果采取真空蒸镀方式，能够得到性能良好的复合集流体，但是设备工艺成本较高，不利于广泛应用。
发明内容
本发明的目的就在于针对上述现有技术的不足，提供一种复合集流体，还 提供一种复合集流体的制备方法及锂离子电池，以解决高能量密度和安全性的双重提升的问题。通过轻量化技术结合补锂层和导电热敏材料层的复合集流体来进一步提升锂离子电池能量密度及安全性。
本发明的目的是通过以下技术方案实现的：
一种复合集流体，由多孔箔材、补锂层以及热敏性材料的导电安全层组成；所述多孔箔材由金属导电材或碳基导电材料制成，材料的孔隙率为0％～60％；所述补锂层由锂金属材料或锂金属化合物材料制成；所述热敏性材料的导电安全层的材料由具有正温度系数材料、导电材料及粘接剂组成。
进一步地，所述金属导电材料优选铜、铝、镍、钛；所述碳基导电材料优选硬碳、软碳、石墨、乙炔黑、石墨烯、碳纳米管。
进一步地，所述复合集流体厚度为5um～25um，多孔箔材材料的厚度为4um～20um，补锂层材料的厚度为5um～15um，热敏性材料的导电安全层的厚度为3um～15um。
进一步地，可用于正极部分补锂层的金属锂化学物材料优选为富锂化合物，或基于转化反应的纳米复合材料，可用于负极部分补锂层优选为金属锂带、稳定化锂金属粉末、硅化锂粉。
进一步地，所述正温度系数材料为高分子聚合物材料，优选高密度聚乙烯、聚偏氟乙烯、羧酸改性的聚偏氟乙烯、丙烯酸改性的聚偏氟乙烯、聚偏氯乙烯、羧酸改性的聚偏氯乙烯、丙烯酸改性的聚偏氯乙烯、聚偏氟乙烯共聚物、聚偏氯乙烯共聚物材料；也可以是可膨胀石墨类材料，优选颗粒型、中等起始膨胀温度的可膨胀石墨。
进一步地，所述正温度系数材料wt％为75％～90％，导电材料wt％为5％～15％， 粘接剂材料wt％为5％～15％。
进一步地，所述导电材料为金属导电材料、碳基导电材料中的一种，金属导电材料优选铜、铝、镍、钛金属颗粒材料；所述的碳基导电材料优选硬碳、软碳、石墨、乙炔黑、石墨烯、碳纳米管材料。
进一步地，所述粘接剂优选聚丙烯酸酯、聚碳酸酯、聚环氧乙烷、橡胶、聚氨酯、羧甲基纤维素钠、聚丙烯酸、明胶、壳聚糖、环糊精的羟基衍生物材料。
一种复合集流体的制备方法，包括以下步骤：
A、通过密集打孔或电沉积形成多孔箔材；
B、再根据多孔箔材的厚度及孔隙率来确定多孔箔材、补锂层以及热敏性材料的导电安全层的材料种类与厚度；
C、通过涂布法、浸涂法实现集流体和热敏性材料的导电安全层的复合，在制备的复合集流体上进行活性材料的涂覆。
一种锂离子电池，包括正极极片、隔膜和负极极片，其中，正极极片、负极极片的集流体可选用复合集流体，在复合集流体的双面涂覆活性物质，制备得到正极极片和负极极片可直接应用于电池中。
与现有技术相比，本发明的有益效果是：
1、正极材料铝箔集流体、负极的铜箔集流体的厚度较现有材料可减薄30％，同时通过造孔技术实现金属集流体的轻量化，而且为了保证多孔的薄基材的使用强度，通过物理及化学技术对基材进行复合处理，可进一步增加孔隙率占比达到50％；
2、可在表面及孔洞覆盖锂金属或锂金属化合物的补锂层，可对于使用含硅 的负极材料在首次化成时起到补锂的所用，达到提升负极活性材料的首次效率的效果，进一步为提升锂离子电池的能量密度提供新的解决方案；
3、可直接在表面及孔洞覆盖导电的热敏材料层，或者在锂金属或锂金属化合物表面覆盖导电的热敏材料层，不仅保证了锂离子电池在正常使用时具备更高的能量密度，同时，当锂离子电池发生热失控时，热敏材料通过膨胀及吸收电解液等方式实现锂离子电池内阻急剧上升，切断锂离子电池热失控链式反应，减轻甚至避免了锂离子电池的热扩散带来的巨大危害。
附图说明
为了更清楚地说明本发明实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本发明的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1不同孔隙率的集流体示意图；
图2复合集流体；
图3利用复合集流体制作的电极示意图。
具体实施方式
下面结合实施例对本发明作进一步说明：
下面结合附图和实施例对本发明作进一步的详细说明。可以理解的是，此处所描述的具体实施例仅仅用于解释本发明，而非对本发明的限定。另外还需要说明的是，为了便于描述，附图中仅示出了与本发明相关的部分而非全部结 构。
应注意到：相似的标号和字母在下面的附图中表示类似项，因此，一旦某一项在一个附图中被定义，则在随后的附图中不需要对其进行进一步定义和解释。同时，在本发明的描述中，术语“第一”、“第二”等仅用于区分描述，而不能理解为指示或暗示相对重要性。
本发明复合集流体，由轻量化设计的多孔箔材(图2的标识3)、补锂层(图2的标识2、4)、热敏性材料的导电安全层(图2的标识1和5)组成，厚度为5um～25um，如图2所示。
所述复合集流体的材料、孔隙率和厚度设计需满足一定的机械强度，如果强度太弱，无法满足热敏性材料的导电安全保护层的复合工艺，如果太强则存在设计冗余。
所述多孔箔材材料为金属导电材、碳基导电材料中的一种；所述金属导电材料优选铜、铝、镍、钛等；所述碳基导电材料优选硬碳、软碳、石墨、乙炔黑、石墨烯、碳纳米管等。
所述多孔箔材材料的孔隙率为0％～60％，如图1所示。
所述多孔箔材材料的厚度为4um～20um。
所述补锂层由锂金属材料或锂金属化合物材料制成，可用于正极部分补锂层的金属锂化学物材料优选为富锂化合物，如Li 2NiO 2、Li 2NiCuO 2等，或基于转化反应的纳米复合材料，如Nano-M/LiF、Nano-M/LiO等，其中M可为Co、Ni、Fe元素；可用于负极部分补锂层优选为金属锂带、稳定化锂金属粉末(SLMP)、硅化锂粉等。
所述补锂层材料的厚度为5um～15um。
所述热敏材料层中导电安全层的材料由具有正温度系数材料、导电材料及粘接剂组成。
所述正温度系数材料可以是高分子聚合物材料，优选高密度聚乙烯、聚偏氟乙烯、羧酸改性的聚偏氟乙烯、丙烯酸改性的聚偏氟乙烯、聚偏氯乙烯、羧酸改性的聚偏氯乙烯、丙烯酸改性的聚偏氯乙烯、聚偏氟乙烯共聚物、聚偏氯乙烯共聚物材料等；也可以是可膨胀石墨类材料，优选颗粒型、中等起始膨胀温度的可膨胀石墨。
所述正温度系数材料wt％为75％～90％。
所述导电材料为金属导电材料、碳基导电材料中的一种，金属导电材料优选铜、铝、镍、钛金属颗粒材料等；所述的碳基导电材料优选硬碳、软碳、石墨、乙炔黑、石墨烯、碳纳米管材料等。
所述导电材料wt％为5％～15％。
所述粘接剂优选聚丙烯酸酯、聚碳酸酯、聚环氧乙烷、橡胶、聚氨酯、羧甲基纤维素钠、聚丙烯酸、明胶、壳聚糖、环糊精的羟基衍生物材料等。
所述粘接剂材料wt％为5％～15％。
所述热敏性材料的导电安全层的厚度为3um～15um。
所述复合集流体可通过涂布法、浸涂法实现集流体和热敏性材料的导电安全层的复合，涂布法优选辊压涂布、挤压涂布、刮刀涂布、凹版涂布等。
一种复合集流体的制备方法，包括以下步骤：
A、通过密集打孔或电沉积形成多孔箔材；
B、再根据多孔箔材的厚度及孔隙率来确定多孔箔材、补锂层以及热敏性材料的导电安全层的材料种类与厚度；
C、通过涂布法、浸涂法实现集流体和热敏性材料的导电安全层的复合，在制备的复合集流体上进行活性材料的涂覆。
本实施例还提供采用一种锂离子电池，包括正极极片、隔膜和负极极片，其中，正极极片、负极极片的集流体可选用复合集流体(图3的标识2-3-4-5-6)，如图3，在安全复合集流体的双面涂覆活性物质(图3的标识1和7)，制备得到正极极片和负极极片可直接应用于电池中。
本申请的电池可为卷绕式，也可为叠片式。本申请的电池可以为锂离子二次电池、锂一次电池、钠离子电池、镁离子电池中的一种。但并不局限于此。
实施例1
复合集流体的制备：
选用50％孔隙率，5um厚度的金属铝箔，并对铝箔表面进行除污去油处理后备用；采取可膨胀石墨：乙炔黑：CMC：SBR，按wt％为80％：5％：5％：5％的比例在去离子水中进行搅拌，待搅拌均匀后，采用转移涂布的方式在铝箔表面形成一层厚度均匀的涂层，然后80℃烘干备用；采用Li2NiO2：PVDF：SP，按wt％为96％：2.5％：1.5％的比例在NMP中进行搅拌，待搅拌均匀后，采用转移涂布的方式在铝箔表面形成一层厚度均匀的涂层，即可得到复合集流体。
实施例2
选用70％孔隙率，3um厚度的金属铜箔，并对铜箔表面进行除污去油处理后备用；采取羧酸改性的聚偏氟乙烯：石墨：聚丙烯酸，按wt％为75％：10％：15％的比例在NMP溶剂中进行搅拌，待搅拌均匀后，采用提拉浸涂的方式在铜 箔表面形成一层厚度均匀的涂层，然后80℃烘干后备用；采用金属锂带进行机械辊压复合，即可得到复合集流体。
实施例3
带有安全复合集流体的正极极片、负极极片和电池的制备
正极极片：采用三元材料NCM811(LiNi0.8Co0.1Mn0.1O2)、SP和PVDF，以NMP为溶剂，按95％：2％：3％的比例搅拌均匀后涂布在集流体上，此集流体为采用按照上述方法所制备的铝基材安全复合集流体及常规12um的铝箔，作为正极活性物质层，在85℃下烘干后进行冷压，然后切边、裁片、分条，再在85℃真空条件下烘干4小时，焊接极耳，制成正极极片。
负极极片：采用石墨、SP、CMC、SBR，以去离子水为溶剂，按96.5％：1％：1％：1.5％的比例搅拌均匀后涂布在集流体上，此集流体为采用按照上述方法所制备的铜基材安全复合集流体及常规8um的铜箔，作为负极活性物质层，在85℃下烘干后进行冷压，然后切边、裁片、分条，再在85℃真空条件下烘干4小时，焊接极耳，制成负极极片。
电池的制备：通过常规的电池制作工艺，将正极极片(压实密度：3.4g/cm3)、PP/PE/PP隔膜和负极极片(压实密度：1.6g/cm3)一起卷绕成裸电芯，然后置入电池壳体中，注入电解液(EC:EMC体积比为3:7，LiPF6为1mol/L)，随之进行密封、化成等工序，最终得到锂离子电池，如表1所示。
实施例4
电池的测试：
安全测试：采取针刺测试进行电池安全性能的比对，将二次电池以1C电流满充至充电截止电压，再恒压充电至电流降至0.05C，停止充电。用的耐高温钢针(针尖的圆锥角度为45°)，以25mm/s的速度，从垂直于电池极板的方向贯穿，贯穿位置靠近所刺面的几何中心，钢针停留在电池中，观察电池是否有燃烧、爆炸现象。
循环测试：采用0.3C充电到截止电压，再恒压充电至电流降至0.05C，停止充电，静置5min，然后1C放电至截止电压，按此程序循环到1000周后，以放电容量作为容量保持率计算标准。
表1电池设计
Figure PCTCN2022141266-appb-000001
表2电池测试结果
  第1000周平均容量保持率％ 针刺结果
电池1 88.3％ 5个通过，5个未通过
电池2 88.8％ 8个通过，2个未通过
电池3 88.2％ 9个通过，1个未通过
电池4 88.4％ 10个全部通过
本发明涉及的集流体为锂离子电池通用正负极所使用的金属铝箔和金属铜箔，在箔材制造过程中，可通过密集打孔或电沉积形成微孔箔材等方式实现， 制造多孔金属箔材的工艺先对成熟，可根据需要选取不同孔隙率的箔材，再根据金属箔材的厚度及孔隙率来确定金属锂或锂金属化合物及导电涂层的种类及厚度，最后在制备的复合集流体上进行活性材料的涂覆。即本发明复合集流体包含轻量化设计的多孔金属箔材、锂金属或锂金属化合物、具有热敏性质的导电安全保护层，由于复合层可提升多孔金属箔材的机械强度，大幅提升了金属箔材的孔隙率设计，从而实现提升锂离子电池的能量密度。同时，锂金属或锂金属化合物可对于使用含硅的负极材料在首次化成时起到补锂的所用，达到提升负极活性材料的首次效率的效果，进一步为提升锂离子电池的能量密度提供新的解决方案，另外，由于导电的热敏材料层的存在，当电池的异常情况发生热失控风险，大电流使热敏材料基体材料温度迅速上升至聚合物熔融温度时体积急剧膨胀并伴随晶相向非晶相转变，导电填料在基体中迁移扩散而分散于整个体积，大量导电链被破坏，电阻剧增使回路电流迅速变小，可迅速实现切断导电网络，同时吸收部分可燃性电解液，降低电池产热量，从而改善电池的安全性能。
注意，上述仅为本发明的较佳实施例及所运用技术原理。本领域技术人员会理解，本发明不限于这里所述的特定实施例，对本领域技术人员来说能够进行各种明显的变化、重新调整和替代而不会脱离本发明的保护范围。因此，虽然通过以上实施例对本发明进行了较为详细的说明，但是本发明不仅仅限于以上实施例，在不脱离本发明构思的情况下，还可以包括更多其他等效实施例，而本发明的范围由所附的权利要求范围决定。

Claims (10)

  1. 一种复合集流体，其特征在于：由多孔箔材、补锂层以及热敏性材料的导电安全层组成；所述多孔箔材由金属导电材或碳基导电材料制成，材料的孔隙率为0％～60％；所述补锂层由锂金属材料或锂金属化合物材料制成；所述热敏性材料的导电安全层的材料由具有正温度系数材料、导电材料及粘接剂组成。
  2. 根据权利要求1所述的一种复合集流体，其特征在于：所述金属导电材料优选铜、铝、镍、钛；所述碳基导电材料优选硬碳、软碳、石墨、乙炔黑、石墨烯、碳纳米管。
  3. 根据权利要求1所述的一种复合集流体，其特征在于：所述复合集流体厚度为5um～25um，多孔箔材材料的厚度为4um～20um，补锂层材料的厚度为5um～15um，热敏性材料的导电安全层的厚度为3um～15um。
  4. 根据权利要求1所述的一种复合集流体，其特征在于：可用于正极部分补锂层的金属锂化学物材料优选为富锂化合物，或基于转化反应的纳米复合材料，可用于负极部分补锂层优选为金属锂带、稳定化锂金属粉末、硅化锂粉。
  5. 根据权利要求1所述的一种复合集流体，其特征在于：所述正温度系数材料为高分子聚合物材料，优选高密度聚乙烯、聚偏氟乙烯、羧酸改性的聚偏氟乙烯、丙烯酸改性的聚偏氟乙烯、聚偏氯乙烯、羧酸改性的聚偏氯乙烯、丙烯酸改性的聚偏氯乙烯、聚偏氟乙烯共聚物、聚偏氯乙烯共聚物材料；也可以是可膨胀石墨类材料，优选颗粒型、中等起始膨胀温度的可膨胀石墨。
  6. 根据权利要求1所述的一种复合集流体，其特征在于：所述正温度系数材料wt％为75％～90％，导电材料wt％为5％～15％，粘接剂材料wt％为5％～15％。
  7. 根据权利要求1所述的一种复合集流体，其特征在于：所述导电材料属导电材、碳基导电材料中的一种，金属导电材料优选铜、铝、镍、钛金属颗粒 材料；所述的碳基导电材料优选硬碳、软碳、石墨、乙炔黑、石墨烯、碳纳米管材料。
  8. 根据权利要求1所述的一种复合集流体，其特征在于：所述粘接剂优选聚丙烯酸酯、聚碳酸酯、聚环氧乙烷、橡胶、聚氨酯、羧甲基纤维素钠、聚丙烯酸、明胶、壳聚糖、环糊精的羟基衍生物材料。
  9. 一种复合集流体的制备方法，其特征在于，包括以下步骤：
    A、通过密集打孔或电沉积形成多孔箔材；
    B、再根据多孔箔材的厚度及孔隙率来确定多孔箔材、补锂层以及热敏性材料的导电安全层的材料种类与厚度；
    C、通过涂布法、浸涂法实现集流体和热敏性材料的导电安全层的复合，在制备的复合集流体上进行活性材料的涂覆。
  10. 一种锂离子电池，其特征在于：包括正极极片、隔膜和负极极片，其中，正极极片、负极极片的集流体可选用复合集流体，在复合集流体的双面涂覆活性物质，制备得到正极极片和负极极片可直接应用于电池中。
PCT/CN2022/141266 2022-02-10 2022-12-23 一种复合集流体、制备方法及锂离子电池 WO2023151400A1 (zh)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117594749A (zh) * 2024-01-15 2024-02-23 上海瑞浦青创新能源有限公司 一种硅基负极片及其制备方法和应用
CN117878335A (zh) * 2024-03-12 2024-04-12 清华大学 复合集流体及其制备方法、电极极片、电池和用电装置

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114709422A (zh) * 2022-02-10 2022-07-05 中国第一汽车股份有限公司 一种复合集流体、制备方法及锂离子电池
CN115000414B (zh) * 2022-06-15 2024-07-05 欣旺达惠州动力新能源有限公司 一种集流体及其制备方法与应用
CN115842096A (zh) * 2022-07-19 2023-03-24 宁德时代新能源科技股份有限公司 预锂化极片及其制备方法、二次电池和用电装置
CN115810759B (zh) * 2022-10-17 2024-09-06 宁德时代新能源科技股份有限公司 柔性复合集流体及其制备方法、极片和电池
CN116598419A (zh) * 2023-06-29 2023-08-15 广州方邦电子股份有限公司 一种复合箔材、电池极片及电化学储能装置
CN117878432B (zh) * 2024-03-11 2024-05-31 蜂巢能源科技股份有限公司 一种电芯及其制备方法和应用

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108899471A (zh) * 2018-06-22 2018-11-27 安徽省力霸动力锂电池科技有限公司 一种正极片及制备方法
CN109004287A (zh) * 2018-08-09 2018-12-14 珠海光宇电池有限公司 一种含有ptc效应集流体的锂离子电池的制备方法
CN109755463A (zh) * 2017-11-08 2019-05-14 宁德时代新能源科技股份有限公司 一种电极极片、电化学装置及安全涂层
CN111430723A (zh) * 2020-04-26 2020-07-17 天津市捷威动力工业有限公司 补锂集流体及其制备方法、应用、负极极片和锂离子电池
CN112599723A (zh) * 2020-12-03 2021-04-02 天津市捷威动力工业有限公司 补锂负极极片及其制备方法和锂离子电池
CN114709422A (zh) * 2022-02-10 2022-07-05 中国第一汽车股份有限公司 一种复合集流体、制备方法及锂离子电池

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005158582A (ja) * 2003-11-27 2005-06-16 Sanyo Electric Co Ltd 電池ホルダ
WO2011060023A2 (en) * 2009-11-11 2011-05-19 Amprius Inc. Preloading lithium ion cell components with lithium
CN104409681A (zh) * 2014-11-19 2015-03-11 上海航天电源技术有限责任公司 一种含ptc涂层的锂离子电池极片的制备方法
CN112467314A (zh) * 2020-11-03 2021-03-09 东莞市创明电池技术有限公司 热敏材料、电极及其制备方法、锂二次电池

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109755463A (zh) * 2017-11-08 2019-05-14 宁德时代新能源科技股份有限公司 一种电极极片、电化学装置及安全涂层
CN108899471A (zh) * 2018-06-22 2018-11-27 安徽省力霸动力锂电池科技有限公司 一种正极片及制备方法
CN109004287A (zh) * 2018-08-09 2018-12-14 珠海光宇电池有限公司 一种含有ptc效应集流体的锂离子电池的制备方法
CN111430723A (zh) * 2020-04-26 2020-07-17 天津市捷威动力工业有限公司 补锂集流体及其制备方法、应用、负极极片和锂离子电池
CN112599723A (zh) * 2020-12-03 2021-04-02 天津市捷威动力工业有限公司 补锂负极极片及其制备方法和锂离子电池
CN114709422A (zh) * 2022-02-10 2022-07-05 中国第一汽车股份有限公司 一种复合集流体、制备方法及锂离子电池

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117594749A (zh) * 2024-01-15 2024-02-23 上海瑞浦青创新能源有限公司 一种硅基负极片及其制备方法和应用
CN117594749B (zh) * 2024-01-15 2024-04-09 上海瑞浦青创新能源有限公司 一种硅基负极片及其制备方法和应用
CN117878335A (zh) * 2024-03-12 2024-04-12 清华大学 复合集流体及其制备方法、电极极片、电池和用电装置
CN117878335B (zh) * 2024-03-12 2024-06-04 清华大学 复合集流体及其制备方法、电极极片、电池和用电装置

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