WO2022204908A1

WO2022204908A1 - Carbon current collector and electrochemical device

Info

Publication number: WO2022204908A1
Application number: PCT/CN2021/083793
Authority: WO
Inventors: 李志愿
Original assignee: 宁德新能源科技有限公司
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2022-10-06
Also published as: CN114514642A

Abstract

The present application relates to a carbon current collector, an electrochemical device, and an electronic device. The carbon current collector comprises a carbon fiber; the carbon fiber is of a hollow tubular structure, and the tube wall of the hollow fiber tubular structure has a through hole; the through hole runs through the tube wall in a direction from the inner diameter to the outer diameter of the tube wall. The carbon current collector of the present application has a relatively high liquid-retaining capability, and improves the battery rate and low-temperature performance.

Description

一种碳集流体及电化学装置A carbon current collector and electrochemical device

技术领域technical field

本申请涉及储能领域，具体涉及一种碳集流体及电化学装置。The present application relates to the field of energy storage, in particular to a carbon current collector and an electrochemical device.

背景技术Background technique

近年来，便携式电子产品如智能手机、笔记本电脑、平板电脑等不断更新换代，曲面显示屏、智能服装、电子皮肤、可植入医疗器械等越来越多的电子设备正在向着轻薄化、柔性化和可穿戴的方向发展。目前为电子产品供电的电化学装置，包括电池和超级电容器等，很难实现灵活弯折，难以满足未来柔性电子技术发展的需求。因此发展柔性电子技术必须要发展与之适应的轻薄且柔性的新型锂离子电池。而发展柔性锂离子电池的主要困难在于如何获得高性能的柔性轻质电极极片。In recent years, portable electronic products such as smartphones, notebook computers, tablet computers, etc. have been constantly updated, and more and more electronic devices such as curved display screens, smart clothing, electronic skin, and implantable medical devices are becoming thinner and more flexible. And the direction of wearable development. At present, the electrochemical devices that power electronic products, including batteries and supercapacitors, are difficult to achieve flexible bending, and it is difficult to meet the needs of future flexible electronic technology development. Therefore, the development of flexible electronic technology must develop a new type of thin and flexible lithium-ion battery that is suitable for it. The main difficulty in developing flexible lithium-ion batteries is how to obtain high-performance flexible and lightweight electrode sheets.

当前锂离子电池集流体以铜箔和铝箔为主，是除了正负极材料外电池中最重的部分，且金属材料柔韧性差，不适用用柔性电极中。可弯折柔性锂离子电池的柔性基体主要有2种：(1)非导电性柔性基体，如高分子聚合物、纸张、纺织布。(2)导电性柔性基体，主要采用石墨烯或碳纳米管等碳材料薄膜作为柔性基体，活性物质附着在其结构单元中形成柔性电极。其在质量方面具有明显优势，是柔性电池高能量密度、轻量化的主流发展方向。At present, the current collectors of lithium-ion batteries are mainly copper foil and aluminum foil, which are the heaviest part of the battery except for the positive and negative electrode materials, and the metal material has poor flexibility, so it is not suitable for flexible electrodes. There are two main types of flexible substrates for bendable and flexible lithium-ion batteries: (1) Non-conductive flexible substrates, such as polymers, paper, and textiles. (2) Conductive flexible substrate, mainly using carbon material films such as graphene or carbon nanotubes as the flexible substrate, and the active material is attached to its structural unit to form a flexible electrode. It has obvious advantages in quality and is the mainstream development direction of flexible batteries with high energy density and light weight.

为了满足柔性电子器件待机时间长、充电时间短的特性，要求柔性储能器件具有高的能量密度和功率密度。目前已报道的柔性锂离子电池的电化学性能，特别在高功率性能方面，仍远远达不到常规锂离子电池的水平，也远不能满足实际应用的需求。因此在高功率性能方面的提高是目前柔性锂离子电池研究领域的难点，而与常规锂离子电池相同，较低的锂离子迁移率是限制高功率性能的重要原因。In order to meet the characteristics of long standby time and short charging time of flexible electronic devices, flexible energy storage devices are required to have high energy density and power density. The electrochemical performance of the currently reported flexible lithium-ion batteries, especially in terms of high power performance, is still far from the level of conventional lithium-ion batteries, and it is far from meeting the needs of practical applications. Therefore, the improvement of high-power performance is a difficulty in the current research field of flexible lithium-ion batteries, and like conventional lithium-ion batteries, low lithium-ion mobility is an important reason for limiting high-power performance.

发明内容SUMMARY OF THE INVENTION

针对现有技术存在的问题，本申请提供一种碳集流体，该碳集流体不仅轻质柔性而且可提升电池倍率性能。本申请还提供了包括该碳集流体的电化学装置和电子装置。In view of the problems existing in the prior art, the present application provides a carbon current collector, which is not only lightweight and flexible, but also can improve the battery rate performance. The present application also provides electrochemical devices and electronic devices including the carbon current collectors.

在第一方面，本申请提供一种碳集流体，包括碳纤维，其中，所述碳纤维为中空管状结构，并且所述中空管状结构的管壁具有通孔。根据本申请，所述通孔贯通所述管壁的内壁面及外壁面。In a first aspect, the present application provides a carbon current collector, comprising carbon fibers, wherein the carbon fibers are hollow tubular structures, and the tube walls of the hollow tubular structures have through holes. According to the present application, the through hole penetrates the inner wall surface and the outer wall surface of the pipe wall.

根据本申请的一些实施方式，所述通孔的孔径为0.02μm至0.05μm。According to some embodiments of the present application, the diameter of the through hole is 0.02 μm to 0.05 μm.

根据本申请的一些实施方式，所述碳集流体的孔隙率为5％至60％。According to some embodiments of the present application, the carbon current collector has a porosity of 5% to 60%.

根据本申请的一些实施方式，所述碳集流体具有以下特征a)至d)中的至少一者：a)电阻为3mΩ至100mΩ，b)拉伸强度为300MPa至1000MPa，c)延伸率为2％至8％，d)经120℃烘烤15min后，电阻为初始电阻的98％以上，拉伸强度强度为初始拉伸强度的98％以上。According to some embodiments of the present application, the carbon current collector has at least one of the following characteristics a) to d): a) electrical resistance of 3 mΩ to 100 mΩ, b) tensile strength of 300 MPa to 1000 MPa, c) elongation of 2% to 8%, d) After baking at 120°C for 15 minutes, the resistance is above 98% of the initial resistance, and the tensile strength is above 98% of the initial tensile strength.

根据本申请的一些实施方式，所述碳集流体的厚度为3μm至30μm。According to some embodiments of the present application, the thickness of the carbon current collector is 3 μm to 30 μm.

根据本申请的一些实施方式，所述中空管状结构的外径为0.1μm至5μm，和/或，所述中空管状结构的内径与外径之比为10％至80％。According to some embodiments of the present application, the outer diameter of the hollow tubular structure is 0.1 μm to 5 μm, and/or the ratio of the inner diameter to the outer diameter of the hollow tubular structure is 10% to 80%.

根据本申请的一些实施方式，所述碳集流体满足以下条件中的至少一者：e)所述碳纤维的强度为100MPa至1000MPa；f)所述碳纤维的延伸率为1％至5％；g)所述碳纤维的总孔隙率为5％至70％，其中通孔的孔隙率为4％至60％，中空管道的孔隙率为1％至66％；h)所述碳纤维的电解液通量为1L·m ^-2·h ^-1至50L·m ^-2·h ^-1。 According to some embodiments of the present application, the carbon current collector satisfies at least one of the following conditions: e) the strength of the carbon fibers is 100 MPa to 1000 MPa; f) the elongation of the carbon fibers is 1% to 5%; g ) The total porosity of the carbon fibers is 5% to 70%, wherein the porosity of the through holes is 4% to 60%, and the porosity of the hollow pipes is 1% to 66%; h) The electrolyte flux of the carbon fibers 1 L·m ^-2 ·h ^-1 to 50 L·m ^-2 ·h ^-1 .

根据本申请的一些实施方式，所述碳集流体的表面还设置有金属层。根据本申请的一些实施方式，所述碳集流体满足以下条件中的至少一者：所述金属层在所述碳集流体表面的正投影面积占比为<70％；所述金属层的厚度<2μm；所述金属层中的金属包括铜、铝、金、银或镍中的至少一种。According to some embodiments of the present application, the surface of the carbon current collector is further provided with a metal layer. According to some embodiments of the present application, the carbon current collector satisfies at least one of the following conditions: the proportion of the orthographic projection area of the metal layer on the surface of the carbon current collector is <70%; the thickness of the metal layer <2 μm; the metal in the metal layer includes at least one of copper, aluminum, gold, silver or nickel.

在第二方面，本申请还提供了如上述第一方面的碳集流体的制备方法，其包括以下步骤：将前驱体经纺丝成前驱体纤维，其中所述前驱体包括聚合物和造孔剂；将前驱体纤维进行拉伸定型，并脱除其中的造孔剂；将脱除造孔剂后的前驱体纤维编织为前驱体织物；将前驱体织物碳化。In a second aspect, the present application also provides a method for preparing a carbon current collector according to the above-mentioned first aspect, comprising the steps of: spinning a precursor into a precursor fiber, wherein the precursor includes a polymer and a pore-forming material agent; stretch and shape the precursor fiber, and remove the pore-forming agent; weave the precursor fiber after removing the pore-forming agent into a precursor fabric; carbonize the precursor fabric.

根据本申请的一些实施方式，所述聚合物选自聚丙烯腈、聚酰亚胺、聚苯并咪唑、聚苯并噁唑、聚苯并噻唑、聚喹噁啉中的一种或多种。According to some embodiments of the present application, the polymer is selected from one or more of polyacrylonitrile, polyimide, polybenzimidazole, polybenzoxazole, polybenzothiazole, and polyquinoxaline .

根据本申请的一些实施方式，所述前驱体织物包括单向织物、双向织物、多轴向织物中的一种或几种。According to some embodiments of the present application, the precursor fabric includes one or more of a unidirectional fabric, a bidirectional fabric, and a multiaxial fabric.

根据本申请的一些实施方式，所述造孔剂选自聚乙烯醇(PVA)和聚乙二醇(PEG)中的至少一种。According to some embodiments of the present application, the pore-forming agent is selected from at least one of polyvinyl alcohol (PVA) and polyethylene glycol (PEG).

根据本申请的一些实施方式，所述将前驱体织物碳化包括将前驱体织物于1000-1500 ℃，1℃-10℃/min升温速率下，氮气保护气氛中煅烧。According to some embodiments of the present application, the carbonizing of the precursor fabric includes calcining the precursor fabric at a temperature of 1000-1500° C. and a heating rate of 1° C.-10° C./min in a nitrogen protective atmosphere.

在第三方面，本申请还提供了一种电化学装置，该电化学装置包括第一方面所述的碳集流体。In a third aspect, the present application also provides an electrochemical device comprising the carbon current collector of the first aspect.

在第四方面，本申请还提供了一种电子装置，该电子装置包括第三方面所述的电化学装置。In a fourth aspect, the present application further provides an electronic device comprising the electrochemical device of the third aspect.

附图说明Description of drawings

图1为根据本申请的实施方式的碳集流体截面的示意图。FIG. 1 is a schematic diagram of a cross section of a carbon current collector according to an embodiment of the present application.

图2为根据本申请的实施方式的碳集流体表面的示意图。2 is a schematic diagram of a carbon current collector surface according to an embodiment of the present application.

图3示出了电解液在根据本申请的实施方式的碳集流体中迁移的示意图。3 shows a schematic diagram of electrolyte migration in carbon current collectors according to embodiments of the present application.

图4为根据本申请的实施方式的集流体截面的电镜图。4 is an electron microscope view of a cross section of a current collector according to an embodiment of the present application.

具体实施方式Detailed ways

下面结合具体实施方式，进一步阐述本申请。应理解，这些具体实施方式仅用于说明本申请而不用于限制本申请的范围。The present application will be further described below in conjunction with specific embodiments. It should be understood that these specific embodiments are only used to illustrate the present application and not to limit the scope of the present application.

在第一方面，本申请提供一种碳集流体，该碳集流体包括碳纤维，其中，所述碳纤维为中空管状结构，并且所述中空纤维管状结构的管壁具有通孔，所述通孔沿所述管壁的内径至外径方向贯通。In a first aspect, the present application provides a carbon current collector, the carbon current collector includes carbon fibers, wherein the carbon fibers are hollow tubular structures, and a tube wall of the hollow fiber tubular structure has through holes, the through holes along the The inner diameter to the outer diameter direction of the pipe wall penetrates.

根据本申请的实施方式，中空管状结构包括中空管道和管壁，通孔位于所述管壁中。如图1和图2所示，其中图1是本申请一个实施方式的碳集流体截面示意图，图2是碳集流体表面示意图。According to an embodiment of the present application, the hollow tubular structure includes a hollow pipe and a pipe wall in which the through hole is located. As shown in FIG. 1 and FIG. 2 , wherein FIG. 1 is a schematic cross-sectional view of a carbon current collector according to an embodiment of the present application, and FIG. 2 is a schematic view of the surface of the carbon current collector.

与现有金属箔材集流体相比，碳材料作为集流体可提升电极柔性与能量密度，其制备的极片适用于柔性电子器件用电池。针对现有柔性锂离子电池的高功率性能较差的缺点，本申请集流体的碳纤维中空结构使集流体具有保液能力，电解液在中空纤维的内径里聚集，管壁上内外壁贯通的通孔使电解液可迅速从中空管道迁移至外部(如图3所示)，提升倍率与低温性能。Compared with the existing metal foil current collectors, the carbon material as the current collector can improve the flexibility and energy density of the electrode, and the prepared electrode sheet is suitable for batteries for flexible electronic devices. In view of the disadvantage of poor high-power performance of the existing flexible lithium-ion battery, the carbon fiber hollow structure of the current collector of the present application enables the current collector to have a liquid-retaining ability, the electrolyte is concentrated in the inner diameter of the hollow fiber, and the inner and outer walls of the tube wall are connected. The pores allow the electrolyte to quickly migrate from the hollow tube to the outside (as shown in Figure 3), improving the rate and low temperature performance.

根据本申请的一些实施方式，所述通孔的孔径为0.02μm至0.05μm。孔径小于0.02μm的通孔制备困难，而当孔径大于0.05μm时，纤维力学性能影响较大，会导致集流体拉伸强度下降。在一些实施例中，通孔的孔径为0.02μm、0.025μm、0.03μm、0.035μm、0.04μm或0.05μm。According to some embodiments of the present application, the diameter of the through hole is 0.02 μm to 0.05 μm. It is difficult to prepare through-holes with a pore size smaller than 0.02 μm, while when the pore size is larger than 0.05 μm, the mechanical properties of the fibers are greatly affected, which will lead to a decrease in the tensile strength of the current collector. In some embodiments, the pore size of the through hole is 0.02 μm, 0.025 μm, 0.03 μm, 0.035 μm, 0.04 μm, or 0.05 μm.

根据本申请的一些实施方式，所述碳纤维的电解液通量为1L·m ^-2·h ^-1至50L·m ^-2·h ^-1，电解液通量指在1bar压力下、单位面积的碳纤维上每小时运输的电解液量。电解液通量可表示管壁上的通孔对电解液的运输能力，在一定程度上表征管壁通孔的贯通程度。在一些实施例中，所述碳纤维的电解液通量为2L·m ^-2·h ^-1、4L·m ^-2·h ^-1、8L·m ^-2·h ^-1、12L·m ^-2·h ^-1、15L·m ^-2·h ^-1、18L·m ^-2·h ^-1、、20L·m ^-2·h ^-1等。 According to some embodiments of the present application, the electrolyte flux of the carbon fiber is 1 L·m ^-2 ·h ^-1 to 50 L·m ^-2 ·h ^-1 , and the electrolyte flux refers to a unit area under a pressure of 1 bar. The amount of electrolyte transported on the carbon fiber per hour. The electrolyte flux can represent the transport capacity of the through-holes on the tube wall to the electrolyte, and to a certain extent characterize the penetration degree of the through-holes in the tube wall. In some embodiments, the electrolyte flux of the carbon fiber is 2L·m ^-2 ·h ^-1 , 4L·m ^-2 ·h ^-1 , 8L·m ^-2 ·h ^-1 , 12L·m ^-2 ·h ⁻¹ , 15L·m ⁻² ·h ⁻¹ , 18L·m ⁻² ·h ^{−1 ,} , 20L·m ⁻² ·h ⁻¹ , etc.

根据本申请的一些实施方式，碳纤维的总孔隙率为5～70％，其中管壁通孔的孔隙率为4～60％，中空管道的孔隙率为1～66％。中空管道的孔隙率越高则保液能力越强，壁上通孔的孔隙率越高则电解液运输能力越强。According to some embodiments of the present application, the total porosity of the carbon fiber is 5-70%, wherein the porosity of the through holes in the tube wall is 4-60%, and the porosity of the hollow pipe is 1-66%. The higher the porosity of the hollow pipe, the stronger the liquid-holding capacity, the higher the porosity of the through-holes on the wall, the stronger the electrolyte transport capacity.

根据本申请的一些实施方式，所述碳集流体的孔隙率为5％至60％。在一些实施例中，所述碳集流体的孔隙率为10％、15％、20％、25％、30％、35％、40％、45％、50％或55％。碳集流体的孔隙率增加有利于保液能力提升，但是孔隙率过高的话，会造成力学性能下降。According to some embodiments of the present application, the carbon current collector has a porosity of 5% to 60%. In some embodiments, the carbon current collector has a porosity of 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or 55%. The increase in the porosity of the carbon current collector is beneficial to the improvement of the liquid-holding capacity, but if the porosity is too high, the mechanical properties will decrease.

根据本申请的一些实施方式，所述碳集流体的电阻为3mΩ至100mΩ。根据一些实施例，使用四探针法测试碳集流体的电阻。在一些实施例中，所述碳集流体的电阻为5mΩ、10mΩ、15mΩ、20mΩ、30mΩ、40mΩ、50mΩ、55mΩ、60mΩ、80mΩ或90mΩ。According to some embodiments of the present application, the carbon current collector has a resistance of 3 mΩ to 100 mΩ. According to some embodiments, the electrical resistance of the carbon current collector is tested using a four-point probe method. In some embodiments, the carbon current collector has a resistance of 5mΩ, 10mΩ, 15mΩ, 20mΩ, 30mΩ, 40mΩ, 50mΩ, 55mΩ, 60mΩ, 80mΩ, or 90mΩ.

根据本申请的一些实施方式，所述碳集流体的拉伸强度为300MPa至1000MPa，延伸率为2％至8％。According to some embodiments of the present application, the carbon current collector has a tensile strength of 300 MPa to 1000 MPa and an elongation of 2% to 8%.

根据本申请的一些实施方式，所述碳集流体经120℃烘烤15min后，电阻为初始电阻的98％以上，拉伸强度为初始拉伸强度的98％以上。According to some embodiments of the present application, after the carbon current collector is baked at 120° C. for 15 minutes, the resistance is more than 98% of the initial resistance, and the tensile strength is more than 98% of the initial tensile strength.

根据本申请的一些实施方式，所述碳集流体的厚度为3μm至30μm。集流体的厚度增加，对于力学性能无影响，电解液保有量有一定增加，对性能有改善。但是，集流体厚度增加会损失体积能量密度，因此综合考虑优选不超过30μm。碳集流体的厚度的测量可以使用万分尺测试12个位置，取平均值。According to some embodiments of the present application, the thickness of the carbon current collector is 3 μm to 30 μm. The increase in the thickness of the current collector has no effect on the mechanical properties, and the electrolyte retention increases to a certain extent, which improves the performance. However, an increase in the thickness of the current collector will result in loss of volumetric energy density, so it is preferable not to exceed 30 μm in comprehensive consideration. The thickness of the carbon current collector can be measured at 12 locations using a micrometer and averaged.

根据本申请的一些实施方式，所述中空管状结构的外径为0.1μm至5μm。外径为整体碳纤维的直径。集流体为编织结构制备而成，若碳纤维外径较大，则达到目标厚度的集流体所需编织层数较少，最终集流体很难达到厚度均匀性；若纤维外径较小，则内部孔结构曲折度很高，不利于锂离子传导，纤维之间接触很多使电子传导受一定影响。在一些实施例中，所述中空管状结构的外径为0.2μm、0.4μm、0.6μm、0.8μm、1.0μm、1.2μm、1.4μm、1.6μm、2.0μm、2.2μm、2.5μm、或3.0μm等。According to some embodiments of the present application, the outer diameter of the hollow tubular structure is 0.1 μm to 5 μm. The outer diameter is the diameter of the overall carbon fiber. The current collector is prepared from a braided structure. If the outer diameter of the carbon fiber is large, the number of braiding layers required to achieve the target thickness of the current collector is less, and it is difficult for the final current collector to achieve thickness uniformity; if the outer diameter of the fiber is small, the internal The tortuosity of the pore structure is very high, which is not conducive to the conduction of lithium ions. In some embodiments, the outer diameter of the hollow tubular structure is 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.4 μm, 1.6 μm, 2.0 μm, 2.2 μm, 2.5 μm, or 3.0 μm μm, etc.

根据本申请的一些实施方式，所述中空管状结构的内径与外径之比(内径/外径)为10％至80％。所述内径为中空管状结构的直径。集流体碳纤维内径/外径增大有利于保液能力提升，但若内径占比过大，则使集流体力学性能下降，且在后续制备中的压实过程与极片冷压过程中难以维持其截面中空的贯通结构。在一些实施例中，所述中空管状结构的内径与外径之比为10％、20％、25％、30％、35％、40％、45％、50％、55％、60％、65％、70％、75％或80％等。According to some embodiments of the present application, the ratio of inner diameter to outer diameter (inner diameter/outer diameter) of the hollow tubular structure is 10% to 80%. The inner diameter is the diameter of the hollow tubular structure. The increase of the inner diameter/outer diameter of the carbon fiber of the current collector is beneficial to the improvement of the liquid retention capacity, but if the inner diameter is too large, the mechanical properties of the current collector will decrease, and it will be difficult to maintain in the compaction process and the cold pressing process of the pole piece in the subsequent preparation. Its cross-section is hollow through structure. In some embodiments, the ratio of inner diameter to outer diameter of the hollow tubular structure is 10%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65% %, 70%, 75% or 80% etc.

根据本申请的一些实施方式，所述碳纤维的强度为100MPa至1000MPa，延伸率为1％至5％。According to some embodiments of the present application, the carbon fiber has a strength of 100 MPa to 1000 MPa and an elongation of 1% to 5%.

根据本申请的一些实施方式，所述碳集流体的表面还设置有金属层。碳集流体表面加金属涂层有利于提升其电子传导，可在主材电导率低的情况下使用。在一些实施例中，所述金属层中的金属包括铜、铝、金、银或镍中的至少一种，金属层的引入方式可以是电镀、沉积或喷涂。考虑到厚度影响以及电解液保有，所述金属层在所述碳集流体表面的正投影面积占比<70％，厚度<2μm。According to some embodiments of the present application, the surface of the carbon current collector is further provided with a metal layer. Adding metal coating on the surface of the carbon current collector is beneficial to improve its electronic conduction and can be used when the conductivity of the main material is low. In some embodiments, the metal in the metal layer includes at least one of copper, aluminum, gold, silver or nickel, and the introduction of the metal layer may be electroplating, deposition or spraying. Considering the influence of thickness and the retention of the electrolyte, the orthographic projection area of the metal layer on the surface of the carbon current collector is less than 70%, and the thickness is less than 2 μm.

根据本申请的一些实施方式，前驱体织物碳化后，经洗涤、压实后，制得本申请的碳集流体。According to some embodiments of the present application, after the precursor fabric is carbonized, washed and compacted, the carbon current collector of the present application is prepared.

根据本申请的一些实施方式，通过调整纺丝组件形状制备出所述碳纤维的中空管状结构，通过加入造孔剂制孔得到管壁通孔。According to some embodiments of the present application, the hollow tubular structure of the carbon fiber is prepared by adjusting the shape of the spinning assembly, and the through-holes in the tube wall are obtained by adding a pore-forming agent to make holes.

根据本申请的一些实施方式，所述聚合物选自聚丙烯腈、聚酰亚胺、聚苯并咪唑、聚苯并噁唑、聚苯并噻唑、聚喹噁啉中的一种或多种。聚合物种类对性能影响不大，常见碳纤维前驱体均适用于本申请。According to some embodiments of the present application, the polymer is selected from one or more of polyacrylonitrile, polyimide, polybenzimidazole, polybenzoxazole, polybenzothiazole, and polyquinoxaline . The type of polymer has little effect on the performance, and common carbon fiber precursors are suitable for this application.

根据本申请的一些实施方式，所述前驱体织物包括单向织物、双向织物、多轴向织物中的一种或几种。根据本申请的一些实施方式，所述造孔剂选自PVA、PEG中的至少一种。According to some embodiments of the present application, the precursor fabric includes one or more of a unidirectional fabric, a bidirectional fabric, and a multiaxial fabric. According to some embodiments of the present application, the pore-forming agent is selected from at least one of PVA and PEG.

根据本申请的一些实施方式，所述将前驱体织物碳化包括将前驱体织物于1000-1500℃，1℃-10℃/min升温速率下，氮气保护气氛中煅烧。According to some embodiments of the present application, the carbonizing of the precursor fabric includes calcining the precursor fabric at 1000-1500° C. and a heating rate of 1° C.-10° C./min in a nitrogen protective atmosphere.

本申请进一步提供了一种电化学装置，所述电化学装置包括本申请提供的碳集流体。本申请提供的碳集流体可以作为正极极片与负极极片的集流体。The present application further provides an electrochemical device comprising the carbon current collector provided by the present application. The carbon current collector provided in the present application can be used as a current collector for the positive electrode and the negative electrode.

根据一些实施例，所述正极极片包括本申请提供的碳集流体。根据一些实施例，所述正极极片还包括设置在所述碳集流体上的正极活性物质。本申请的正极活性物质没有特别限制，可以使用本领域公知的任何正极活性物质，例如，可以包括镍钴锰酸锂(811、622、523、111)、镍钴铝酸锂、磷酸铁锂、富锂锰基材料、钴酸锂、锰酸锂、磷酸锰铁锂或钛酸锂中的至少一种。According to some embodiments, the positive electrode sheet includes the carbon current collector provided herein. According to some embodiments, the positive electrode sheet further includes a positive active material disposed on the carbon current collector. The positive active material of the present application is not particularly limited, and any positive active material known in the art can be used, for example, it can include nickel cobalt lithium manganate (811, 622, 523, 111), nickel cobalt lithium aluminate, lithium iron phosphate, At least one of lithium-rich manganese-based material, lithium cobaltate, lithium manganate, lithium iron manganese phosphate or lithium titanate.

根据一些实施例，所述负极极片包括本申请提供的碳集流体。根据一些实施例，所述负极极片还包括设置在所述碳集流体上的负极活性物质。本申请中的负极活性物质没有特别限制，可以使用本领域公知的任何负极活性物质。例如，可以包括人造石墨、天然石墨、中间相碳微球、软碳、硬碳、硅、硅碳、钛酸锂等中的至少一种。According to some embodiments, the negative pole piece includes the carbon current collector provided herein. According to some embodiments, the negative pole piece further includes a negative active material disposed on the carbon current collector. The negative electrode active material in the present application is not particularly limited, and any negative electrode active material known in the art can be used. For example, at least one of artificial graphite, natural graphite, mesocarbon microspheres, soft carbon, hard carbon, silicon, silicon carbon, lithium titanate, and the like may be included.

本申请的电化学装置，例如锂离子电池，还包括电解质，电解质可以是凝胶电解质、固态电解质和电解液中的一种或多种，电解液包括锂盐和非水溶剂。The electrochemical device of the present application, such as a lithium ion battery, further includes an electrolyte, and the electrolyte may be one or more of a gel electrolyte, a solid electrolyte, and an electrolyte, and the electrolyte includes a lithium salt and a non-aqueous solvent.

在本申请一些实施方案中，锂盐选自LiPF ₆、LiBF ₄、LiAsF ₆、LiClO ₄、LiB(C ₆H ₅) ₄、LiCH ₃SO ₃、LiCF ₃SO ₃、LiN(SO ₂CF ₃) ₂、LiC(SO ₂CF ₃) ₃、LiSiF ₆、LiBOB和二氟硼酸锂中的一种或多种。举例来说，锂盐可以选用LiPF ₆，因为它可以给出高的离子导电率并改善循环特性。 In some embodiments of the present application, the lithium salt is selected from LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiClO ₄ , LiB(C ₆ H ₅ ) ₄ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) _2. One or more of LiC(SO ₂ CF ₃ ) ₃ , LiSiF ₆ , LiBOB and lithium difluoroborate. For example, LiPF ₆ may be chosen as the lithium salt because it gives high ionic conductivity and improves cycling characteristics.

非水溶剂可为碳酸酯化合物、羧酸酯化合物、醚化合物、其它有机溶剂或它们的组合。The non-aqueous solvent may be a carbonate compound, a carboxylate compound, an ether compound, other organic solvents, or a combination thereof.

上述碳酸酯化合物可为链状碳酸酯化合物、环状碳酸酯化合物、氟代碳酸酯化合物或其组合。The above-mentioned carbonate compound may be a chain carbonate compound, a cyclic carbonate compound, a fluorocarbonate compound, or a combination thereof.

上述链状碳酸酯化合物的实例为碳酸二甲酯(DMC)、碳酸二乙酯(DEC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸甲乙酯(MEC)及其组合。环状碳酸酯化合物的实例为碳酸亚乙酯(EC)、碳酸亚丙酯(PC)、碳酸亚丁酯(BC)、碳酸乙烯基亚乙酯(VEC)及其组合。氟代碳酸酯化合物的实例为碳酸氟代亚乙酯(FEC)、碳酸1,2-二氟亚乙酯、碳酸1,1-二氟亚乙酯、碳酸1,1,2-三氟亚乙酯、碳酸1,1,2,2-四氟亚乙酯、碳酸1-氟-2-甲基亚乙酯、碳酸1-氟-1-甲基亚乙酯、碳酸1,2-二氟-1-甲基亚乙酯、碳酸1,1,2-三氟-2-甲基亚乙酯、碳酸三氟甲基亚乙酯及其组合。Examples of the above-mentioned chain carbonate compound are dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), carbonic acid Methyl ethyl ester (MEC) and combinations thereof. Examples of cyclic carbonate compounds are ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylethylene carbonate (VEC), and combinations thereof. Examples of fluorocarbonate compounds are fluoroethylene carbonate (FEC), 1,2-difluoroethylene carbonate, 1,1-difluoroethylene carbonate, 1,1,2-trifluoroethylene carbonate Ethyl carbonate, 1,1,2,2-tetrafluoroethylene carbonate, 1-fluoro-2-methylethylene carbonate, 1-fluoro-1-methylethylene carbonate, 1,2-dicarbonate Fluoro-1-methylethylene, 1,1,2-trifluoro-2-methylethylene carbonate, trifluoromethylethylene carbonate, and combinations thereof.

上述羧酸酯化合物的实例为甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸正丙酯、乙酸叔丁酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、γ-丁内酯、癸内酯、戊内酯、甲瓦龙酸内酯、己内酯及其组合。Examples of the above-mentioned carboxylate compounds are methyl formate, methyl acetate, ethyl acetate, n-propyl acetate, tert-butyl acetate, methyl propionate, ethyl propionate, propyl propionate, γ-butyrolactone , caprolactone, valerolactone, mevalonolactone, caprolactone, and combinations thereof.

上述醚化合物的实例为二丁醚、四甘醇二甲醚、二甘醇二甲醚、1,2-二甲氧基乙烷、 1,2-二乙氧基乙烷、乙氧基甲氧基乙烷、2-甲基四氢呋喃、四氢呋喃及其组合。Examples of the above ether compounds are dibutyl ether, tetraglyme, diglyme, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethyl ether Oxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, and combinations thereof.

上述其它有机溶剂的实例为二甲亚砜、1,2-二氧戊环、环丁砜、甲基环丁砜、1,3-二甲基-2-咪唑烷酮、N-甲基-2-吡咯烷酮、甲酰胺、二甲基甲酰胺、乙腈、磷酸三甲酯、磷酸三乙酯、磷酸三辛酯、和磷酸酯及其组合。Examples of the above-mentioned other organic solvents are dimethyl sulfoxide, 1,2-dioxolane, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone, Formamide, dimethylformamide, acetonitrile, trimethyl phosphate, triethyl phosphate, trioctyl phosphate, and phosphate esters and combinations thereof.

本申请的电化学装置中使用的隔膜的材料和形状没有特别限制，其可为任何现有技术中公开的技术。在一些实施例中，隔膜包括由对本申请的电解液稳定的材料形成的聚合物或无机物等。The material and shape of the separator used in the electrochemical device of the present application are not particularly limited, and it may be any technique disclosed in the prior art. In some embodiments, the separator includes a polymer or inorganic or the like formed from a material that is stable to the electrolyte of the present application.

例如隔膜可包括基材层和表面处理层。基材层为具有多孔结构的无纺布、膜或复合膜，基材层的材料选自聚乙烯、聚丙烯、聚对苯二甲酸乙二醇酯和聚酰亚胺中的至少一种。具体的，可选用聚丙烯多孔膜、聚乙烯多孔膜、聚丙烯无纺布、聚乙烯无纺布或聚丙烯-聚乙烯-聚丙烯多孔复合膜。For example, the separator may include a substrate layer and a surface treatment layer. The base material layer is a non-woven fabric, film or composite film with a porous structure, and the material of the base material layer is selected from at least one of polyethylene, polypropylene, polyethylene terephthalate and polyimide. Specifically, a polypropylene porous membrane, a polyethylene porous membrane, a polypropylene non-woven fabric, a polyethylene non-woven fabric or a polypropylene-polyethylene-polypropylene porous composite membrane can be selected.

基材层的至少一个表面上设置有表面处理层，表面处理层可以是聚合物层或无机物层，也可以是混合聚合物与无机物所形成的层。At least one surface of the base material layer is provided with a surface treatment layer, and the surface treatment layer may be a polymer layer or an inorganic material layer, or a layer formed by mixing a polymer and an inorganic material.

无机物层包括无机颗粒和粘结剂，无机颗粒选自氧化铝、氧化硅、氧化镁、氧化钛、二氧化铪、氧化锡、二氧化铈、氧化镍、氧化锌、氧化钙、氧化锆、氧化钇、碳化硅、勃姆石、氢氧化铝、氢氧化镁、氢氧化钙和硫酸钡中的至少一种。粘结剂选自聚偏氟乙烯、偏氟乙烯-六氟丙烯的共聚物、聚酰胺、聚丙烯腈、聚丙烯酸酯、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚甲基丙烯酸甲酯、聚四氟乙烯和聚六氟丙烯中的至少一种。The inorganic layer includes inorganic particles and a binder, and the inorganic particles are selected from aluminum oxide, silicon oxide, magnesium oxide, titanium oxide, hafnium oxide, tin oxide, ceria, nickel oxide, zinc oxide, calcium oxide, zirconium oxide, At least one of yttrium oxide, silicon carbide, boehmite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, and barium sulfate. The binder is selected from polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyamide, polyacrylonitrile, polyacrylate, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinylalkoxy , at least one of polymethyl methacrylate, polytetrafluoroethylene and polyhexafluoropropylene.

聚合物层中包含聚合物，聚合物的材料选自聚酰胺、聚丙烯腈、丙烯酸酯聚合物、聚丙烯酸、聚丙烯酸盐、聚乙烯呲咯烷酮、聚乙烯烷氧、聚偏氟乙烯、聚(偏氟乙烯-六氟丙烯)中的至少一种。The polymer layer contains a polymer, and the material of the polymer is selected from polyamide, polyacrylonitrile, acrylate polymer, polyacrylic acid, polyacrylate, polyvinylpyrrolidone, polyvinylalkoxy, polyvinylidene fluoride, At least one of poly(vinylidene fluoride-hexafluoropropylene).

本申请进一步提供了一种电子装置，其包括本申请所述的电化学装置。The present application further provides an electronic device comprising the electrochemical device described herein.

本申请的电子设备或装置没有特别限定。在一些实施例中，本申请的电子设备包括但不限于，笔记本电脑、笔输入型计算机、移动电脑、电子书播放器、便携式电话、便携式传真机、便携式复印机、便携式打印机、头戴式立体声耳机、录像机、液晶电视、手提式清洁器、便携CD机、迷你光盘、收发机、电子记事本、计算器、存储卡、便携式录音机、收音机、备用电源、电机、汽车、摩托车、助力自行车、自行车、照明器具、玩具、游戏机、钟表、电动工具、闪光灯、照相机、家庭用大型蓄电池和锂离子电容器等。The electronic equipment or device of the present application is not particularly limited. In some embodiments, electronic devices of the present application include, but are not limited to, notebook computers, pen input computers, mobile computers, e-book players, portable telephones, portable fax machines, portable copiers, portable printers, headsets , VCR, LCD TV, Portable Cleaner, Portable CD Player, Mini CD, Transceiver, Electronic Notepad, Calculator, Memory Card, Portable Recorder, Radio, Backup Power, Motor, Automobile, Motorcycle, Power-assisted Bicycle, Bicycle , lighting equipment, toys, game consoles, clocks, power tools, flashes, cameras, large household batteries and lithium-ion capacitors, etc.

为了简明，本文仅具体地公开了一些数值范围。然而，任意下限可以与任何上限组合形成未明确记载的范围；以及任意下限可以与其它下限组合形成未明确记载的范围，同样任意上限可以与任意其它上限组合形成未明确记载的范围。此外，每个单独公开的点或单个数值自身可以作为下限或上限与任意其它点或单个数值组合或与其它下限或上限组合形成未明确记载的范围。For the sake of brevity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form a non-specifically recited range; and any lower limit can be combined with any other lower limit to form a non-specifically recited range, and likewise any upper limit can be combined with any other upper limit to form an unspecifiedly recited range. Furthermore, each individually disclosed point or single value may itself serve as a lower or upper limit in combination with any other point or single value or with other lower or upper limits to form a range that is not expressly recited.

在本文的描述中，除非另有说明，“以上”、“以下”包含本数。In the description herein, unless otherwise stated, "above" and "below" include the numerals.

除非另有说明，本申请中使用的术语具有本领域技术人员通常所理解的公知含义。除非另有说明，本申请中提到的各参数的数值可以用本领域常用的各种测量方法进行测量(例如，可以按照在本申请的实施例中给出的方法进行测试)。Unless otherwise specified, terms used in this application have their commonly known meanings as commonly understood by those skilled in the art. Unless otherwise specified, the values of the parameters mentioned in this application can be measured by various measurement methods commonly used in the art (for example, can be tested according to the methods given in the examples of this application).

术语“中的至少一者”、“中的至少一个”、“中的至少一种”或其他相似术语所连接的项目的列表可意味着所列项目的任何组合。例如，如果列出项目A及B，那么短语“A及B中的至少一者”意味着仅A；仅B；或A及B。在另一实例中，如果列出项目A、B及C，那么短语“A、B及C中的至少一者”意味着仅A；或仅B；仅C；A及B(排除C)；A及C(排除B)；B及C(排除A)；或A、B及C的全部。项目A可包含单个组分或多个组分。项目B可包含单个组分或多个组分。项目C可包含单个组分或多个组分。A list of items to which the terms "at least one of," "at least one of," "at least one of," or other similar terms are linked to can mean any combination of the listed items. For example, if items A and B are listed, the phrase "at least one of A and B" means A only; B only; or A and B. In another example, if items A, B, and C are listed, the phrase "at least one of A, B, and C" means A only; or B only; C only; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

一、实施例和对比例中使用的聚合物1. Polymers used in Examples and Comparative Examples

聚丙烯腈：分子量15万；Polyacrylonitrile: molecular weight 150,000;

聚酰亚胺：分子量40万；Polyimide: molecular weight 400,000;

聚苯并咪唑：分子量50万；Polybenzimidazole: molecular weight 500,000;

聚苯并噁唑：分子量50万。Polybenzoxazole: molecular weight of 500,000.

二、测试方法2. Test method

碳纤维单根丝强度和延伸率：参考标准GB/T 14337-2008化学纤维短纤维拉伸性能试验方法。使用XQ-1电子单纤维强力测试仪，测试单根纤维，夹具间距为10mm，测试12根样条取平均值，计算样品拉断时的强度与延伸率。 Carbon fiber single fiber strength and elongation : reference standard GB/T 14337-2008 chemical fiber short fiber tensile properties test method. Use XQ-1 electronic single fiber strength tester to test a single fiber with a clamp spacing of 10mm, test 12 splines to take the average value, and calculate the strength and elongation of the sample when it breaks.

碳纤维内径、外径：取12根中空碳纤维，使用IB-09010CP切割得到截面，使用SIGMA/X-max场发射扫描电镜测试每根中空碳纤维的内径与外径，每根选取3个位置，取所有数据的平均值。 Carbon fiber inner diameter and outer diameter : Take 12 hollow carbon fibers, use IB-09010CP to cut the cross section, use SIGMA/X-max field emission scanning electron microscope to test the inner diameter and outer diameter of each hollow carbon fiber, select 3 positions for each, take all the average of the data.

碳纤维管壁通孔的孔径：取12根中空碳纤维，使用SIGMA/X-max场发射扫描电镜测试纤维外径表面的孔径，每根选取3个位置，取所有数据的平均值。 Diameter of through holes in carbon fiber tube wall : Take 12 hollow carbon fibers, use SIGMA/X-max field emission scanning electron microscope to test the diameter of the outer diameter surface of the fibers, select 3 positions for each, and take the average value of all data.

碳纤维孔隙率：参考标准GB/T 21650压汞法和气体吸附法测定固体材料孔径分布和孔隙度。取100根20mm长的碳纤维样品，称重；使用Autopore V 9620压汞仪进行测试，将样品放入样品管进行密封；设备开机，样品管置于低压仓进行低压充汞，低压充汞充满后，将样品管放入高压仓中进行高压充汞，高压充汞充满后进行退汞。输出孔分布曲线，孔径大于50nm为大孔、由碳纤维的中空管道贡献，孔径小于50nm为小孔、由碳纤维管壁通孔贡献，计算100根碳纤维总体积为V0，大孔体积为V1，小孔体积为V2，则碳纤维中空管道孔隙率为V1/V0，碳纤维管壁通孔孔隙率为V2/V0。 Carbon fiber porosity : refer to the standard GB/T 21650 mercury porosimetry and gas adsorption method to determine the pore size distribution and porosity of solid materials. Take 100 carbon fiber samples with a length of 20 mm and weigh them; use an Autopore V 9620 mercury porosimeter for testing, and put the samples into the sample tube for sealing; when the equipment is turned on, the sample tube is placed in a low-pressure chamber for low-pressure mercury charging. , Put the sample tube into the high-pressure chamber for high-pressure mercury filling, and then carry out the mercury-removal after the high-pressure mercury filling is full. Output pore distribution curve, the pore size greater than 50nm is the macropore, contributed by the hollow pipe of carbon fiber, the pore size smaller than 50nm is the small hole, contributed by the through hole of the carbon fiber tube wall, the total volume of 100 carbon fibers is calculated as V0, the macropore volume is V1, and the small pore volume is V0. The pore volume is V2, the porosity of the carbon fiber hollow pipe is V1/V0, and the porosity of the through-hole of the carbon fiber pipe wall is V2/V0.

碳纤维的电解液通量：参照标准HY/T 049-1999中空纤维反渗透膜测试方法。取20根长度为20cm的碳纤维置于膜组件中，中空纤维两侧均固定保证无弯曲打皱现象，膜组件与液体收集组件相连、保证密闭无漏液，从膜组件一侧以1bar的压力通电解液(EC/DMC＝1/1，锂盐为1mol/L的LiPF ₆)、以一定的流速经过膜的内径表面，由于碳纤维的管壁通孔结构，一部分电解液会从通孔中透过进入液体收集组件，其余电解液则循环使用。测试48h内的电解液收集的量为V，20根中空碳纤维内径总面积为A，通量计算公式为V/(48×A)。 Electrolyte flux of carbon fiber : refer to the standard HY/T 049-1999 hollow fiber reverse osmosis membrane test method. Take 20 carbon fibers with a length of 20cm and place them in the membrane module. Both sides of the hollow fiber are fixed to ensure no bending and wrinkling. The membrane module is connected to the liquid collection module to ensure airtightness and no leakage. The pressure of 1 bar is applied from one side of the membrane module. The electrolyte (EC/DMC=1/1, LiPF ₆ with lithium salt of 1 mol/L) passes through the inner diameter surface of the membrane at a certain flow rate. Due to the through-hole structure of the carbon fiber tube wall, a part of the electrolyte will flow out of the through-hole. By entering the liquid collection component, the rest of the electrolyte is recycled. The amount of electrolyte collected within 48h of the test is V, the total area of the inner diameter of 20 hollow carbon fibers is A, and the flux calculation formula is V/(48×A).

集流体平均厚度：取40cm长、20cm宽的集流体，保证集流体平整无打皱，使用Mitutoyo万分尺测试此尺寸范围内的12个不同位置厚度，取平均值。 Average thickness of current collector : Take a current collector with a length of 40cm and a width of 20cm to ensure that the current collector is flat and wrinkle-free. Use a Mitutoyo micrometer to test the thickness of 12 different positions within this size range, and take the average value.

集流体电阻：取40cm长、20cm宽的集流体，保证集流体平整无打皱，使用BER1300电阻仪，选择四探针法，测试此尺寸范围内的12个不同位置电阻，取平均值。 Current collector resistance : Take a current collector with a length of 40cm and a width of 20cm to ensure that the current collector is flat and wrinkle-free. Use a BER1300 resistance meter and choose the four-point probe method to test the resistance of 12 different positions within this size range and take the average value.

集流体拉伸强度和延伸率：取40cm长、20cm宽的集流体，保证集流体平整无打皱，厚度为d，沿长度方向裁为宽12mm、长100mm样条，使用Instron3365万能试验机，选择拉伸夹具进行测试，夹具间距即测试段长度为50mm，拉伸速率10mm/min，样品拉断时长度为L、拉力为F，延伸率计算为(L-100)/100，拉伸强度计算为F/(d*12)，测试12根样条取平均值，计算样品拉断时的拉伸强度与延伸率。 Tensile strength and elongation of the current collector: Take a current collector with a length of 40cm and a width of 20cm to ensure that the current collector is flat and wrinkle-free. The thickness is d. Select a tensile fixture for testing. The distance between the fixtures is 50mm, the length of the test section is 50mm, the tensile rate is 10mm/min, the length when the sample is broken is L, the tensile force is F, the elongation is calculated as (L-100)/100, and the tensile strength is Calculated as F/(d*12), test 12 splines to take the average value, and calculate the tensile strength and elongation of the sample when it breaks.

集流体孔结构：参考标准GB/T 21650压汞法和气体吸附法测定固体材料孔径分布和孔隙度。取3条20mm宽、300mm长的集流体样品，称重；使用Autopore V 9620压汞仪进行测试，将样品沿长度方向卷起并放入样品管进行密封；设备开机，样品管置于低压仓进行低压充汞，低压充汞充满后，将样品管放入高压仓中进行高压充汞，高压充汞充满后进行退汞。样品体积为V0，总充孔体积为V1，V1/V0为孔隙率，取3条样品平均值。 Current collector pore structure : refer to the standard GB/T 21650 mercury porosimetry and gas adsorption method to determine the pore size distribution and porosity of solid materials. Take 3 current collector samples with a width of 20mm and a length of 300mm, and weigh them; use an Autopore V 9620 mercury porosimeter for testing, roll up the samples along the length direction and put them into the sample tube for sealing; the device is turned on, and the sample tube is placed in a low-pressure chamber Carry out low-pressure mercury filling, after low-pressure mercury-filling, put the sample tube into the high-pressure chamber for high-pressure mercury-filling, and then carry out mercury-removal after high-pressure mercury-filling. The sample volume is V0, the total filling volume is V1, and V1/V0 is the porosity, and the average value of three samples is taken.

金属涂层覆盖度(金属涂层在碳集流体表面的正投影面积占比)：取12片集流体样品，尺寸10mm×10mm，使用KEYENCE VHX5000进行测试，放大倍数为500倍，自动测量面积模式计算覆盖度，取12片平均值。 Coverage of metal coating ( the proportion of the orthographic projection area of the metal coating on the surface of the carbon current collector): Take 12 current collector samples, size 10mm×10mm, use KEYENCE VHX5000 to test, the magnification is 500 times, the automatic measurement area mode Calculate the coverage and take the average of 12 slices.

金属涂层厚度：取12片集流体样品，尺寸10mm×10mm，使用IB-09010CP切割得到截面，使用SIGMA/X-max场发射扫描电镜测试12片集流体的截面金属涂层厚度，每片选取3个位置，取所有数据的平均值。 Thickness of metal coating : Take 12 pieces of current collector samples, size 10mm×10mm, use IB-09010CP to cut the cross section, use SIGMA/X-max field emission scanning electron microscope to test the thickness of metal coating on the cross section of 12 pieces of current collector, each piece is selected 3 positions, take the average of all data.

1.5C充电容量保持率：25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05C，充电容量为C0，0.5C直流放电至0％SOC，1.5C恒流充电至100％SOC、充电容量为C1，C1/C0。 1.5C charging capacity retention rate : at 25°C, the cell with SOC of 0% is charged to 100% SOC with 0.2C constant current, and constant voltage is charged to 0.05C, the charging capacity is C0, and the 0.5C DC discharge is to 0% SOC, 1.5C constant current charging to 100% SOC, charging capacity is C1, C1/C0.

2C放电容量保持率：25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05V，0.2C直流放电至0％SOC，放电容量为D0，0.2C恒流充电至100％SOC、恒压充电至0.05V，2C直流放电至0％SOC，放电容量为D1，D1/D0。 2C discharge capacity retention rate : at 25°C, the cell with SOC of 0% is charged to 100% SOC with 0.2C constant current, constant voltage charged to 0.05V, 0.2C DC discharge to 0% SOC, the discharge capacity is D0, 0.2 C constant current charge to 100% SOC, constant voltage charge to 0.05V, 2C DC discharge to 0% SOC, the discharge capacity is D1, D1/D0.

-20℃_0.5C容量保持率：25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05V，0.5C直流放电至0％SOC，放电容量为D0；25℃下将SOC为0％的电芯以0.2C恒流充电至100％SOC、恒压充电至0.05V，-20℃下以0.5C直流放电至0％SOC，放电容量为D1，D1/D0。 -20℃_0.5C capacity retention rate : at 25℃, charge the cell with SOC of 0% to 100% SOC with 0.2C constant current, charge to 0.05V with constant voltage, and discharge 0.5C DC to 0% SOC, the discharge capacity It is D0; at 25°C, the cell with SOC of 0% is charged to 100% SOC with 0.2C constant current, charged to 0.05V with constant voltage, and discharged to 0% SOC with 0.5C DC at -20°C, and the discharge capacity is D1 , D1/D0.

三、碳集流体的制备：3. Preparation of carbon current collectors:

将聚合物溶解于溶剂DMAc中制备出聚合物溶液，加入萃取剂(PVA、PEG中的至少一种)混合均匀，溶液固含量在3～20％之间；Dissolving the polymer in the solvent DMAc to prepare a polymer solution, adding an extractant (at least one of PVA and PEG) and mixing evenly, the solid content of the solution is between 3-20%;

使用中空湿法纺丝组件、凝固浴使用饱和硫酸钠溶液对上述聚合物溶液进行湿法纺丝，得到中空纤维(中空贯通结构)，使用纤维热拉伸设备对中空纤维进行热拉伸定型；Using a hollow wet spinning assembly, a coagulation bath, and a saturated sodium sulfate solution to wet-spin the above-mentioned polymer solution to obtain a hollow fiber (hollow through-structure), and use a fiber hot-stretching device to heat-stretch and shape the hollow fiber;

将中空纤维置于85℃的水中洗去萃取剂，使中空纤维的管壁上具有通孔；The hollow fiber is placed in water at 85°C to wash off the extractant, so that there are through holes on the tube wall of the hollow fiber;

将中空纤维编织为织物，织物结构可以是单向织物、双向织物、多轴向织物中的一种或几种；Weaving the hollow fibers into fabrics, the fabric structure can be one or more of unidirectional fabrics, bidirectional fabrics, and multiaxial fabrics;

将中空纤维织物于1000-1500℃，1℃-10℃/min升温速率下，氮气保护气氛中煅烧3h进行碳化，制备为中空碳纤维织物，使用丙酮对织物进行清洗；The hollow fiber fabric was calcined at 1000-1500°C, at a heating rate of 1°C-10°C/min, in a nitrogen protective atmosphere for 3 hours for carbonization to prepare a hollow carbon fiber fabric, and the fabric was cleaned with acetone;

将中空碳纤维织物进行辊压至目标厚度，分切为目标宽度得到中空碳纤维集流体。The hollow carbon fiber fabric is rolled to a target thickness, and cut to a target width to obtain a hollow carbon fiber current collector.

实施例1Example 1

1、碳集流体的制备：1. Preparation of carbon current collectors:

将聚丙烯腈溶解于溶剂DMAc中制备出聚合物溶液，加入PVA(聚合度400到500，醇解度88％)混合均匀，溶液固含量10％，聚合物与萃取剂的质量比为1：3。使用中空湿法纺丝组件、凝固浴使用饱和硫酸钠溶液对上述聚合物溶液进行湿法纺丝，得到中空纤维(中空贯通结构)，使用纤维热拉伸设备对中空纤维进行热拉伸定型。将中空纤维置于85℃的水中洗去PVA，使中空纤维的管壁上具有通孔。将中空纤维编织为织物，织物结构为双向织物。将中空纤维织物于1100℃，5℃/min升温速率下，保护气氛中煅烧3h进行碳化，制备为中空碳纤维织物。使用丙酮对织物进行清洗；将中空碳纤维织物进行辊压至目标厚度，得到碳集流体。A polymer solution was prepared by dissolving polyacrylonitrile in solvent DMAc, adding PVA (polymerization degree 400 to 500, alcoholysis degree 88%) and mixing evenly, the solid content of the solution was 10%, and the mass ratio of polymer to extractant was 1: 3. The above-mentioned polymer solution was wet-spun using a hollow wet-spinning module and a coagulation bath using a saturated sodium sulfate solution to obtain a hollow fiber (hollow through-hole structure), and the hollow fiber was heat-stretched using a fiber heat-stretching device. The hollow fiber was placed in water at 85° C. to wash off the PVA, so that there were through holes on the tube wall of the hollow fiber. The hollow fibers are woven into a fabric, and the fabric structure is a bidirectional fabric. The hollow fiber fabric was carbonized by calcining at 1100 °C and a heating rate of 5 °C/min in a protective atmosphere for 3 h to prepare a hollow carbon fiber fabric. The fabric was cleaned with acetone; the hollow carbon fiber fabric was rolled to the target thickness to obtain a carbon current collector.

本实施例制备的碳集流体：碳纤维的外径0.2μm，内径/外径＝40％，碳纤维管壁上具有通孔，通孔孔径0.04μm，孔隙率40％，集流体厚度5μm，其他参数见表1。The carbon current collector prepared in this example: the outer diameter of the carbon fiber is 0.2 μm, the inner diameter/outer diameter=40%, the carbon fiber tube wall has through holes, the through hole diameter is 0.04 μm, the porosity is 40%, the thickness of the current collector is 5 μm, and other parameters See Table 1.

2、正极极片的制备：2. Preparation of positive pole pieces:

将正极活性材料钴酸锂、乙炔黑、聚偏二氟乙烯(PVDF)按质量比94：3：3混合，然后加入N-甲基吡咯烷酮(NMP)作为溶剂，调配成固含量为75％的浆料，并搅拌均匀。将浆料均匀涂布在上述碳集流体上，90℃条件下烘干，冷压后得到正极活性材料层厚度为100μm的正极极片，然后在该正极极片的另一个表面上重复以上步骤，得到双面涂布有正极活性材料层的正极极片。将正极极片裁切成74mm×867mm的规格并焊接极耳后待用。The positive active material lithium cobaltate, acetylene black, and polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 94:3:3, and then N-methylpyrrolidone (NMP) was added as a solvent to prepare a solid content of 75%. slurry and mix well. The slurry was evenly coated on the carbon current collector, dried at 90°C, and cold-pressed to obtain a positive electrode sheet with a positive active material layer thickness of 100 μm, and then repeat the above steps on the other surface of the positive electrode sheet , to obtain a positive electrode sheet coated with a positive electrode active material layer on both sides. Cut the positive pole piece into a size of 74mm×867mm and weld the tabs for later use.

3、负极极片的制备3. Preparation of negative pole piece

将负极活性材料人造石墨、乙炔黑、丁苯橡胶及羧甲基纤维素钠按质量比96：1：1.5：1.5混合，然后加入去离子水作为溶剂，调配成固含量为70％的浆料，并搅拌均匀。将浆料均匀涂布在上述碳集流体上，110℃条件下烘干，冷压后得到负极活性材料层厚度为150μm的单面涂布负极活性材料层的负极极片，然后在该负极极片的另一个表面上重复以上涂布步骤，得到双面涂布有负极活性材料层的负极极片。将负极极片裁切成74mm×867mm的规格并焊接极耳后待用。The negative active materials artificial graphite, acetylene black, styrene-butadiene rubber and sodium carboxymethyl cellulose are mixed in a mass ratio of 96:1:1.5:1.5, and then deionized water is added as a solvent to prepare a slurry with a solid content of 70% , and stir well. The slurry was uniformly coated on the above-mentioned carbon current collector, dried at 110°C, and after cold pressing, a negative electrode sheet with a negative electrode active material layer with a thickness of 150 μm was obtained on one side coated with a negative electrode active material layer, and then the negative electrode was placed on the negative electrode. The above coating steps are repeated on the other surface of the sheet to obtain a negative electrode sheet coated with a negative electrode active material layer on both sides. Cut the negative pole piece into a size of 74mm×867mm and weld the tabs for later use.

4、电解液的制备4. Preparation of electrolyte

在含水量小于10ppm的环境下，将非水有机溶剂碳酸乙烯酯(EC)、碳酸二乙酯(DEC)、碳酸亚丙酯(PC)、丙酸丙酯(PP)、碳酸亚乙烯酯(VC)按照质量比20：30：20：28：2混合，然后向非水有机溶剂中加入六氟磷酸锂(LiPF ₆)溶解并混合均匀，得到电解液，其中，LiPF ₆与非水有机溶剂的质量比为8：92。 In an environment with a water content of less than 10 ppm, the non-aqueous organic solvents ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC), propyl propionate (PP), vinylene carbonate ( VC) is mixed according to the mass ratio of 20:30:20:28:2, then lithium hexafluorophosphate (LiPF ₆ ) is added to the non-aqueous organic solvent to dissolve and mix uniformly to obtain an electrolyte, wherein the mass ratio of LiPF ₆ to the non-aqueous organic solvent to 8:92.

5、锂离子电池的制备5. Preparation of lithium-ion batteries

将上述制备的正极极片、隔离膜、负极极片按顺序叠好，将隔离膜具有第一涂层的一面与正极极片接触，将隔离膜具有第二涂层的一面与负极极片接触，并卷绕得到电极组件。将电极组件装入铝塑膜包装袋中，并在80℃下脱去水分，注入配好的电解液，经过真空封装、静置、化成、整形等工序得到锂离子电池。The above-prepared positive pole piece, separator, and negative pole piece are stacked in order, the side of the separator with the first coating is in contact with the positive pole piece, and the side of the separator with the second coating is in contact with the negative pole piece , and rolled to obtain an electrode assembly. Put the electrode assembly into an aluminum-plastic film packaging bag, remove moisture at 80°C, inject the prepared electrolyte, and obtain a lithium-ion battery through the processes of vacuum packaging, standing, forming, and shaping.

对比例1Comparative Example 1

与实施例1不同之处仅在于集流体不同，其中铜箔作为负极集流体，铝箔作为正极集流体。The only difference from Example 1 is that the current collectors are different, in which the copper foil is used as the negative electrode current collector and the aluminum foil is used as the positive electrode current collector.

对比例2Comparative Example 2

与实施例1不同之处仅在于集流体不同，将碳纳米管、聚乙烯(碳纳米管、聚乙烯的质量比为30/70)通过熔融挤出流延成为导电复合膜。对导电复合膜进行热拉伸至厚度为5μm，无孔结构。The only difference from Example 1 is that the current collector is different. Carbon nanotubes and polyethylene (the mass ratio of carbon nanotubes and polyethylene is 30/70) are melt-extruded into conductive composite films. The conductive composite film was thermally stretched to a thickness of 5 μm without a porous structure.

对比例3Comparative Example 3

与对比例2的不同之处仅在于将负极活性材料替换为氧化亚硅。The difference from Comparative Example 2 is only that the negative electrode active material was replaced with silicon oxide.

对比例4Comparative Example 4

与实施例1的不同之处在于，碳纤维的管壁没有通孔，仅仅为具有中空管状结构的碳纤维，其他参数不变，不加入萃取剂可制备出此对比例。The difference from Example 1 is that the tube wall of the carbon fiber has no through-holes, only carbon fibers with a hollow tubular structure, and other parameters remain unchanged, and this comparative example can be prepared without adding an extractant.

对比例5Comparative Example 5

与实施例1的不同之处在于，碳纤维的管壁为孔结构，但无将内外壁贯通的孔，厚度为5μm。制备方法参照前案CN106898778B。The difference from Example 1 is that the tube wall of the carbon fiber has a hole structure, but there is no hole penetrating the inner and outer walls, and the thickness is 5 μm. For the preparation method, refer to the previous case CN106898778B.

表1Table 1

实施例2-15Examples 2-15

参照实施例1，与在实施例1的不同之处在于，调整碳纤维外径、碳纤维内径/外径、碳纤维壁上通孔孔径以及碳纤维前驱体材料，具体参见表2-1和表2-2。Referring to Example 1, the difference from Example 1 is that the outer diameter of the carbon fiber, the inner diameter/outer diameter of the carbon fiber, the diameter of the through hole on the carbon fiber wall, and the carbon fiber precursor material are adjusted, as shown in Table 2-1 and Table 2-2 for details. .

实施例16-24Examples 16-24

实施例16-22参照实施例3，与在实施例3的不同之处在于，调整碳纤维织物结构、集流体厚度或增加集流体表面金属涂层。具体地，实施例23参照实施例3，与在实施例3的不同之处在于，将负极活性材料由石墨替换为氧化亚硅，实施例24参照实施例22，与在实施例22的不同之处在于，将负极活性材料由石墨替换为氧化亚硅，集流体孔隙率均为40％、碳纤维单丝延伸率均为2.2％、碳纤维单丝强度均为350MPa。具体参见表3。Examples 16-22 refer to Example 3, and differ from Example 3 in that the structure of the carbon fiber fabric, the thickness of the current collector, or the metal coating on the surface of the current collector is adjusted. Specifically, Example 23 refers to Example 3, and the difference from Example 3 is that the anode active material is replaced by graphite with silicon oxide. Example 24 refers to Example 22, which is different from Example 22. The point is that the negative electrode active material is replaced by graphite with silicon oxide, the porosity of the current collector is all 40%, the elongation of the carbon fiber monofilament is all 2.2%, and the strength of the carbon fiber monofilament is all 350MPa. See Table 3 for details.

表2-1table 2-1

表2-2Table 2-2

表3table 3

通过表1可以看出，本申请提供的碳集流体与现有金属箔材集流体相比，可提升电极柔性与能量密度，引入的多孔结构可以使集流体具有保液能力，提升了倍率与低温性能；此外，本申请集流体管壁上内外径贯通的通孔使电解液可迅速从中空纤维内部迁移至外部，因此与对比例4、对比例5相比，性能有所提升。It can be seen from Table 1 that, compared with the existing metal foil current collectors, the carbon current collectors provided by this application can improve the flexibility and energy density of the electrodes, and the introduced porous structure can make the current collectors have the ability to retain liquid, which improves the rate and energy density. Low temperature performance; in addition, the through holes with inner and outer diameters on the wall of the current collector tube of the present application allow the electrolyte to quickly migrate from the inside of the hollow fiber to the outside, so compared with Comparative Example 4 and Comparative Example 5, the performance is improved.

根据表2实施例1至5，随着碳纤维外径增大(0.2μ至2μm，由于达到目标厚度的集流体所需纤维层数减少，纤维之间接触电阻降低，使电阻有一定下降，同时由于孔隙率一致，锂离子迁移路径减少、曲折度减弱增加，性能得到了一定改善。According to Examples 1 to 5 in Table 2, as the outer diameter of the carbon fiber increases (0.2 μm to 2 μm, the number of fiber layers required to reach the target thickness of the current collector decreases, and the contact resistance between fibers decreases, so that the resistance decreases to a certain extent. Due to the uniform porosity, the lithium ion migration path is reduced, and the tortuosity is weakened and increased, and the performance has been improved to a certain extent.

相比实施例3，实施例6-9改变了碳纤维内径/外径。根据表2，随着集流体碳纤维内径/外径增大，集流体孔隙率随之增加，有利于保液能力提升，对性能有一定改善。但是内径/外径过大会造成力学性能有一定下降，因此，综合考虑，内径/外径优选为40％至60％。Compared with Example 3, Examples 6-9 changed the carbon fiber inner diameter/outer diameter. According to Table 2, as the inner diameter/outer diameter of the carbon fiber of the current collector increases, the porosity of the current collector increases, which is beneficial to the improvement of the liquid retention capacity and the performance to a certain extent. However, if the inner diameter/outer diameter is too large, the mechanical properties will be degraded to a certain extent. Therefore, considering the overall consideration, the inner diameter/outer diameter is preferably 40% to 60%.

相比实施例3，实施例10-12改变了纤维壁上通孔孔径。由表2可以看出在保证孔隙率一致时，纤维壁上通孔孔径增加对性能影响不大。通孔大小主要受造孔剂影响，孔径小于0.02μm孔制备困难，而当孔径大于0.05μm时，纤维力学性能影响较大会导致集流体强度下降。Compared with Example 3, Examples 10-12 changed the diameter of the through holes on the fiber wall. It can be seen from Table 2 that when the porosity is consistent, the increase in the pore size of the through holes on the fiber wall has little effect on the performance. The size of the through-hole is mainly affected by the pore-forming agent, and it is difficult to prepare pores with a pore size smaller than 0.02 μm. When the pore size is larger than 0.05 μm, the mechanical properties of the fiber are greatly affected, which will lead to a decrease in the strength of the current collector.

相比实施例3，实施例13-15改变了聚合物种类。由表2可以看出聚合物种类对于性能影响不大，因此常用的碳材料前驱体聚合物均适用于本申请。Compared to Example 3, Examples 13-15 changed the polymer species. It can be seen from Table 2 that the polymer type has little effect on the performance, so the commonly used carbon material precursor polymers are all suitable for this application.

相比实施例3，实施例16-18改变了编织物结构。由表3可以看出，较双向与多轴向，单向织物结构碳纤维接触电阻略大，集流体力学性能略差，但对性能影响程度有限，因此，常见编织物结构均适用于本申请。Compared to Example 3, Examples 16-18 changed the braid structure. It can be seen from Table 3 that, compared with bidirectional and multiaxial, the contact resistance of carbon fiber with unidirectional fabric structure is slightly larger, and the mechanical properties of the current collector are slightly worse, but the impact on performance is limited. Therefore, common woven fabric structures are suitable for this application.

相比实施例3，实施例19-21改变了集流体厚度。由表3可以看出，集流体厚度增加，力学性能无影响，电解液保有量有一定增加，对性能有略有改善。Compared to Example 3, Examples 19-21 varied the current collector thickness. It can be seen from Table 3 that the increase in the thickness of the current collector has no effect on the mechanical properties, and the electrolyte retention increases to a certain extent, which slightly improves the performance.

通过实施例3与实施例22对比，实施例23与实施例24对比，可得碳集流体表面加金属涂层可增加其电子传导，但对于主材为石墨的阳极，由于石墨本身电子传导较好，影响较小；对于主材为硅材料的阳极，由于硅材料电子传导差，在集流体表面引入金属涂层有利于性能提升。By comparing Example 3 with Example 22, and Example 23 with Example 24, it can be seen that adding a metal coating on the surface of the carbon current collector can increase its electron conduction, but for the anode whose main material is graphite, the electron conduction of graphite itself is relatively low. Good, the impact is small; for the anode whose main material is silicon material, due to the poor electron conduction of silicon material, the introduction of a metal coating on the surface of the current collector is beneficial to the performance improvement.

Claims

一种碳集流体，包括碳纤维，其中，所述碳纤维为中空管状结构，并且所述中空管状结构的管壁具有通孔，所述通孔贯通所述管壁的内壁面及外壁面。A carbon current collector includes carbon fibers, wherein the carbon fibers have a hollow tubular structure, and a tube wall of the hollow tubular structure has a through hole, and the through hole penetrates the inner wall surface and the outer wall surface of the tube wall.
根据权利要求1所述的碳集流体，其中，所述通孔的孔径为0.02μm至0.05μm。The carbon current collector of claim 1, wherein the through hole has a pore diameter of 0.02 μm to 0.05 μm.
根据权利要求1所述的碳集流体，其中，所述碳集流体的孔隙率为5％至60％。The carbon current collector of claim 1, wherein the carbon current collector has a porosity of 5% to 60%.
根据权利要求1所述的碳集流体，其中，所述碳集流体具有以下特征a)至d)中的至少一者：The carbon current collector of claim 1 , wherein the carbon current collector has at least one of the following characteristics a) to d):

a)电阻为3mΩ至100mΩ，a) The resistance is 3mΩ to 100mΩ,

b)拉伸强度为300MPa至1000MPa，b) Tensile strength from 300MPa to 1000MPa,

c)延伸率为2％至8％，c) elongation of 2% to 8%,

d)经120℃烘烤15min后，电阻为初始电阻的98％以上，拉伸强度为初始拉伸强度的98％以上。d) After baking at 120°C for 15 minutes, the resistance is above 98% of the initial resistance, and the tensile strength is above 98% of the initial tensile strength.
根据权利要求1所述的碳集流体，其中，所述碳集流体的厚度为3μm至30μm。The carbon current collector of claim 1, wherein the carbon current collector has a thickness of 3 μm to 30 μm.
根据权利要求1所述的碳集流体，其中，所述中空管状结构的外径为0.1μm至5μm，和/或，所述中空管状结构的内径与外径之比为10％至80％。The carbon current collector of claim 1, wherein the outer diameter of the hollow tubular structure is 0.1 μm to 5 μm, and/or the ratio of the inner diameter to the outer diameter of the hollow tubular structure is 10% to 80%.
根据权利要求1所述的碳集流体，其中，满足以下条件e)至h)中的至少一者：The carbon current collector of claim 1, wherein at least one of the following conditions e) to h) is satisfied:

e)所述碳纤维的强度为100MPa至1000MPa；e) the strength of the carbon fiber is 100MPa to 1000MPa;

f)所述碳纤维的延伸率为1％至5％；f) the elongation of the carbon fiber is 1% to 5%;

g)所述碳纤维的总孔隙率为5％至70％，其中，所述管壁通孔的孔隙率为4％至60％，中空管道的孔隙率为1％至66％；g) the total porosity of the carbon fiber is 5% to 70%, wherein the porosity of the through hole in the pipe wall is 4% to 60%, and the porosity of the hollow pipe is 1% to 66%;

h)所述碳纤维的电解液通量为1L·m ^-2·h ^-1至50L·m ^-2·h ^-1。 h) The electrolyte flux of the carbon fiber is 1 L·m ^-2 ·h ^-1 to 50 L·m ^-2 ·h ^-1 .
根据权利要求1所述的碳集流体，其中，所述碳集流体的表面还设置有金属层。The carbon current collector according to claim 1, wherein a surface of the carbon current collector is further provided with a metal layer.
根据权利要求8所述的碳集流体，其中，满足以下条件中的至少一者：The carbon current collector of claim 8, wherein at least one of the following conditions is satisfied:

所述金属层在所述碳集流体表面的正投影面积占比为<70％；The proportion of the orthographic projection area of the metal layer on the surface of the carbon current collector is <70%;

所述金属层的厚度<2μm；The thickness of the metal layer is less than 2 μm;

所述金属层中的金属包括铜、铝、金、银或镍中的至少一种。The metal in the metal layer includes at least one of copper, aluminum, gold, silver or nickel.
一种如权利要求1至9任一项所述的碳集流体的制备方法，包括以下步骤：A method for preparing a carbon current collector as claimed in any one of claims 1 to 9, comprising the steps of:

将前驱体经纺丝成前驱体纤维，其中所述前驱体包括聚合物和造孔剂；spinning the precursor into a precursor fiber, wherein the precursor includes a polymer and a pore former;

将前驱体纤维进行拉伸定型，并脱除其中的造孔剂；The precursor fiber is stretched and shaped, and the pore-forming agent is removed;

将脱除造孔剂后的前驱体纤维编织为前驱体织物；Weaving the precursor fiber after removing the pore-forming agent into a precursor fabric;

将前驱体织物碳化。Carbonizing the precursor fabric.
根据权利要求10所述的制备方法，其中，所述聚合物选自聚丙烯腈、聚酰亚胺、聚苯并咪唑、聚苯并噁唑、聚苯并噻唑、聚喹噁啉中的一种或多种。The preparation method according to claim 10, wherein the polymer is selected from the group consisting of polyacrylonitrile, polyimide, polybenzimidazole, polybenzoxazole, polybenzothiazole and polyquinoxaline one or more.
根据权利要求10所述的制备方法，其中，所述前驱体织物包括单向织物、双向织物、多轴向织物中的一种或几种，所述造孔剂选自聚乙烯醇(PVA)、聚乙二醇(PEG)中的至少一种。The preparation method according to claim 10, wherein the precursor fabric comprises one or more of unidirectional fabric, bidirectional fabric, and multiaxial fabric, and the pore-forming agent is selected from polyvinyl alcohol (PVA) , at least one of polyethylene glycol (PEG).
根据权利要求10所述的制备方法，其中，所述将前驱体织物碳化包括将前驱体织物于1000-1500℃，1℃-10℃/min升温速率下，氮气保护气氛中煅烧。The preparation method according to claim 10, wherein the carbonizing the precursor fabric comprises calcining the precursor fabric at 1000-1500°C and a heating rate of 1°C-10°C/min in a nitrogen protective atmosphere.
一种电化学装置，包括如权利要求1-9任一项所述的碳集流体。An electrochemical device comprising the carbon current collector of any one of claims 1-9.
一种电子装置，包括如权利要求14所述的电化学装置。An electronic device comprising the electrochemical device of claim 14 .