WO2017084632A1 - Method for preparing high-quality graphene having controllable layer number by utilizing electrochemical process - Google Patents

Method for preparing high-quality graphene having controllable layer number by utilizing electrochemical process Download PDF

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WO2017084632A1
WO2017084632A1 PCT/CN2016/106625 CN2016106625W WO2017084632A1 WO 2017084632 A1 WO2017084632 A1 WO 2017084632A1 CN 2016106625 W CN2016106625 W CN 2016106625W WO 2017084632 A1 WO2017084632 A1 WO 2017084632A1
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graphite
graphene
intercalation compound
layers
graphite intercalation
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夏永姚
王飞
王永刚
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复旦大学
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  • the invention belongs to the technical field of graphene preparation, and particularly relates to a method for preparing high quality graphene with controllable number of layers by using an electrochemical process.
  • Graphene is a new carbonaceous material that is closely packed into a two-dimensional honeycomb lattice structure by a single layer of carbon atoms.
  • most physicists believed that thermodynamic fluctuations did not allow any two-dimensional crystals to exist at finite temperatures.
  • the physicists of the University of Manchester, André Heim and Konstantin Novoselov used a microfolitation method to prepare a carbon film with a single atomic thickness.
  • the dimensional carbon material exhibits high crystallinity and is unusually stable, and it can exist alone.
  • graphene is another major discovery after carbon nanotubes and fullerene spheres.
  • the methods for preparing graphene include the following: (1) Micromechanical stripping method, wherein the graphene crystal structure obtained by the method is complete, but the yield is too low, and is not suitable for large-scale production; (2) chemical vapor deposition method (CVD), the crystal structure of graphene prepared by this method is relatively complete, and the number of layers can be controlled by control conditions, but the cost is high, the preparation process is high, and it is difficult to achieve scale production; (3) epitaxial growth method, the method can A large area of graphene is obtained, but the graphene sheet is not easy to be separated from the substrate, and the cost is high; (4) solvent stripping method, which can be obtained by mixing graphite and a part of the intercalating agent in a suitable solvent.
  • the present invention uses graphite as a reactive substance, through controlled insertion of a lithium ion (combination, embedding, etc.) intercalation guest (such as a metal salt, a metal oxide, a polymer) through a controlled insertion between graphite layers.
  • a lithium ion (combination, embedding, etc.) intercalation guest such as a metal salt, a metal oxide, a polymer
  • GICs graphite intercalation compounds
  • graphite intercalation compounds are used as electrodes for lithium ion battery negative
  • the van der Waals force between the layers of the graphite intercalation compound disappears and is converted into graphene.
  • graphene with controlled layer number is obtained.
  • the invention destroys the intermolecular force of graphite by electrochemical process, does not need to undergo a violent reaction process such as ultrasonic or expansion, has a mild reaction process, and can accurately control the number of graphene layers, and the obtained graphene sheet has few defects and conductance. High rate and other advantages, easy to large-scale industrial production.
  • the object of the present invention is to develop a simple, large-scale preparation method for the preparation of high quality graphene having a controlled number of layers.
  • the invention provides a method for preparing high quality graphene with controllable number of layers by using an electrochemical process, and the specific steps are as follows:
  • the graphite intercalation compound prepared in the step (1) is used as a battery negative electrode in the electrolyte of the lithium ion battery, and the intermolecular force between the graphene sheets disappears through the charging and discharging process (the process is as shown in FIG. 1). Show) to obtain a graphene composite;
  • the graphene composite obtained in the step (2) is dispersed in a solvent, treated by an ultrasonic method, and then filtered and washed to obtain high-quality graphene of different layers. among them:
  • the ultrasonic time depends on the power level during ultrasonic treatment and the particle size of graphite. Since the intermolecular force has been destroyed, the ultrasonic time can be controlled within 30 minutes (general ultrasound 5-25 minutes), and the ultrasonic power is 200. -2000W, frequency is 15-100kHz;
  • the shearing speed is 10-28000 rpm, and the shearing time is 10 min-30 min;
  • the ball milling speed is 200-1600 rpm, and the ball milling time is 20 min-3 h.
  • the graphite intercalation compound described in the step (1) is generally controlled to have a single order or a compound having a different order between 1 and 10, and the ratio of the graphite to the intercalant and the reaction are adjusted as needed. Conditions, adjustments generate different orders.
  • the method for preparing the graphite intercalation compound according to the step (1) includes one of solid phase insertion, liquid phase insertion, gas phase insertion, or a mixture of several of them.
  • the preparation methods of GICs can be classified into a two-chamber method, a chemical method, an electrochemical method, a mixing method, a press method, and a molten salt method.
  • the common methods for preparing GICs are now described as follows:
  • Double-compartment synthesis of GICs The dual-chamber method is a classical method for the preparation of GICs, and is particularly suitable for the preparation of alkali metal-GICs and metal chloride-GICs.
  • Graphite and insert were placed in the reaction chambers at both ends of the heat-resistant glass reactor. After vacuum sealing, the temperature of the reaction chambers at both ends of the glass reactor was controlled by two sets of electric furnaces to make Tg>Ti (graphite sample). Temperature Tg > temperature of the insert Ti) to ensure that the insert can be smoothly inserted between the graphite layers while preventing the formation of the intercalation compound from decomposing when the temperature is too high;
  • Electrochemical synthesis of GICs is the combination of natural flake graphite and auxiliary anodes into the anode chamber, the intercalant solution as the electrolyte, through the direct current or pulse current, anodizing, deacidification, water washing, dehydration Dried out. This is a method for preparing GICs by inserting an insert into the graphite layer in the form of ions by an electrochemical reaction;
  • GICs by pressurization: mixing alkaline earth metal and rare earth metal powder with graphite matrix and reacting under pressure to form M-GICs;
  • molten salt method (also known as mixed liquid phase method) synthesis of GICs: molten salt method is based on the properties of the eutectic of each component can reduce the melting point of the system (below the melting point of each component), is a A method of preparing ternary or multi-component GICs by inserting two or more substances (which must form a molten salt system) into a graphite layer at the same time. The method allows the reaction material which originally needs a higher reaction temperature to be inserted into the graphite layer to be inserted between the graphite layers at a lower reaction temperature, and thus has important practical value.
  • the methods for synthesizing GICs include photochemical method, catalyst method, explosion method, etc. These synthetic methods each have their own advantages and disadvantages, and the synthetic objects are also different. Because they are less used, they will not be elaborated here.
  • the intercalation body described in the step (1) includes, but is not limited to, natural graphite, modified graphite, artificial graphite (such as HOPG, pitch-based carbon fiber, vapor-grown carbon fiber, polyacrylonitrile carbon fiber, etc.).
  • the graphitized carbon material has at least one of graphite having a layered structure. Some or all of these materials have a graphite structure in which carbon atoms in the layer form covalent bonds with SP 2 hybrid orbital electrons, and each carbon atom forms a metal bond with 2pZ orbital electrons, forming a solid hexagonal network planar carbon layer.
  • the intercalation agent described in the step (1) is one of a metal salt, a metal oxide, a polymer, a simple substance, or a mixture of several of them.
  • the specific substances are shown in Table 1. Specific substances include, but are not limited to, the substances described in Table 1.
  • the charge and discharge process described in the step (2) may be stopped in a discharged state or may be stopped in a charged state.
  • the solvent used includes water and a common organic solvent such as ethanol, benzene or toluene.
  • the graphene obtained by the preparation method of the invention has a graphene layer number of 1-10 layers, a graphite lattice defect is small, and a relatively complete hexagon is formed, and the graphene surface does not contain an epoxy group, a carboxyl group, a hydroxyl group or the like.
  • FIG. 1 is a view showing the process of destroying intermolecular forces by charge and discharge according to the present invention.
  • Figure 3 is a transmission electron microscope (TEM) image of a 2-layer graphene prepared by the present invention.
  • Figure 5 is a graph showing the results of electron transport test of the 2-layer graphene prepared by the present invention.
  • the term “about” means that the value can vary by no more than 1% from the recited value.
  • the expression “about 100” includes all values between 99 and 101 and (eg, 99.1, 99.2, 99.3, 99.4, etc.).
  • the terms "containing” or “including” may be open, semi-closed, and closed. In other words, the terms also include “consisting essentially of,” or “consisting of.”
  • Graphite Intercalation compounds are novel compounds formed by physically or chemically intercalating heteroatoms, molecules or ions between atomic layers, also known as interlayer compounds or interlayer compounds.
  • Graphite intercalation compounds can form interlaminar compounds of different order structures.
  • the order structure of the graphite intercalation compound is usually expressed by the order, and the graphite intercalation compound formed by inserting a layer of intercalation every other layer of carbon atoms is called a first-order graphite intercalation compound.
  • a graphite intercalation compound formed by inserting a layer of intercalation every n-layer carbon atom plane is called an n-th order graphite intercalation compound.
  • Graphene has the same carbon atom arrangement as the monoatomic layer of graphite, and is a single-layer two-dimensional crystal of carbon atoms composed of carbon atoms arranged in a honeycomb lattice in a sp2 hybrid orbital.
  • a layer of graphene composed of a layer of graphene, composed of 2 layers of graphene The two-dimensional carbon material composed of stacking is called double-layer graphene, and the two-dimensional carbon material composed of stacks of three to nine layers of graphene is called a small layer of graphene.
  • the number of graphene layers produced by the present invention is consistent with the order of the graphite intercalation compound precursor.
  • a first-order graphite intercalation compound can produce a single-layer graphene
  • a second-order graphite intercalation compound can produce a bi-layer graphene or the like.
  • graphite is used as a reaction substance, and a layer of intercalated guest capable of storing lithium ions can be controlledly inserted between graphite layers to form a graphite intercalation compound whose order is controllable, thereby realizing the number of graphene layers. Precise control.
  • the second-order ferric chloride copper chloride graphite intercalation compound prepared above was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery.
  • Single electrode testing was performed in the glove box in the order of positive/separator/negative.
  • the single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ⁇ EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery.
  • the battery working range is 0 ⁇ 3.0V
  • the charge and discharge current is 100mA / g
  • the first ring discharge to 0V after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 10 minutes, water washing After washing with dilute hydrochloric acid, two layers of graphene can be obtained (see Figure 2 for details), so that the graphene has few defects (see Figure 3) and the conductivity is excellent (see Figure 4).
  • the second-order ferric chloride copper chloride graphite intercalation compound prepared above was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery.
  • Single electrode testing was performed in the glove box in the order of positive/separator/negative.
  • the single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ⁇ EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery.
  • the battery working range is 0 ⁇ 3.0V
  • the charging and discharging current is 100mA/g
  • the first ring discharges to 0V
  • the battery is charged back to 1.5V.
  • the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonically dispersed for 10 minutes, and washed. After washing with dilute hydrochloric acid and filtering, two layers of graphene can be obtained.
  • the second-order ferric chloride copper chloride graphite intercalation compound prepared above was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery.
  • Single electrode testing was performed in the glove box in the order of positive/separator/negative.
  • the single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ⁇ EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery.
  • the battery working range is 0 ⁇ 3.0V
  • the charge and discharge current is 100mA / g
  • the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonically dispersed for 25 minutes, washed, diluted After washing with hydrochloric acid, filtration was carried out to obtain two layers of graphene.
  • the above-prepared fourth-order ferric chloride graphite intercalation compound was directly pressed on a foamed nickel mesh to form an electrode, which was then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode for a lithium ion battery.
  • Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ⁇ EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery.
  • the battery working range is 0 ⁇ 3.0V
  • the charge and discharge current is 100mA / g
  • the first ring discharge to 0V after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 20 minutes, water washing After washing with dilute hydrochloric acid and filtering, four layers of graphene can be obtained.
  • the above-prepared fourth-order ferric chloride graphite intercalation compound was directly pressed on a foamed nickel mesh to form an electrode, which was then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode for a lithium ion battery.
  • Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ⁇ EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery.
  • the battery working range is 0 ⁇ 3.0V
  • the charge and discharge current is 100mA / g
  • the first ring discharge to 0V after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 10 minutes, water washing After washing with dilute hydrochloric acid and filtering, six layers of graphene can be obtained.
  • the above-mentioned mixed-stage cobalt chloride graphite intercalation compound was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery.
  • Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ⁇ EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery.
  • the battery working range is 0 ⁇ 3.0V
  • the charge and discharge current is 100mA / g
  • the first ring discharge to 0V after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 10 minutes, water washing After washing with dilute hydrochloric acid, the three-layer and four-layer graphene can be obtained.
  • the reaction temperature was too low, and a graphite intercalation compound could not be obtained, so that graphene could not be obtained.

Abstract

A method for preparing high-quality graphene having a controllable layer number by utilizing an electrochemical process comprises: using graphite as a reacting matter, controllably inserting an intercalated object capable of storing lithium ions between layers of the graphite, and forming a graphite intercalation compound having a controllable order; preparing the graphite intercalation compound into an electrode, and using same as a cathode of a lithium ion battery; enabling a van der waals force between the layers of the graphite intercalation compound to disappear through a partially irreversible electrochemical process, and converting the graphite intercalation compound into graphene; and obtaining the graphene having a controllable layer number through treatment of dispersing, washing, and the like. The method damages an intermolecular force of graphite through an electrochemical process, a vigorous reaction process of ultrasound or expansion, and the like is not required, the reaction process is gentle, and the layer number of the graphene can be accurately controlled; and an obtained graphene sheet has the advantages of fewer defects, high conductivity, and the like, and is easy in large-scale industrial production.

Description

一种利用电化学过程制备层数可控的高质量石墨烯的方法Method for preparing high quality graphene with controllable number of layers by electrochemical process 技术领域Technical field
本发明属于石墨烯制备技术领域，具体涉及一种利用电化学过程制备层数可控的高质量石墨烯的方法。The invention belongs to the technical field of graphene preparation, and particularly relates to a method for preparing high quality graphene with controllable number of layers by using an electrochemical process.
背景技术Background technique
石墨烯(graphene)是由单层碳原子紧密堆积成二维蜂窝状晶格结构的一种碳质新材料。在发现石墨烯以前，大多数物理学家认为，热力学涨落不允许任何二维晶体在有限温度下存在。2004年，英国曼彻斯特大学物理学家安德烈·海姆和康斯坦丁·诺沃肖洛夫采用“微机械力***法”(microfolitation)制备了一种单原子厚度的碳膜，这种两维碳材料表现了很高的结晶度而且异乎寻常地稳定，它可以单独存在。毋庸置疑，石墨烯是继碳纳米管、富勒烯球后的又一重大发现，海姆和诺沃肖洛夫两人也因在二维石墨烯材料的开创性研究，共同获得2010年诺贝尔物理学奖。由于石墨烯独特的二维结构和优异的晶体学结构，石墨烯蕴含了丰富而新奇的物理现象，具有重要的理论研究和应用价值。Graphene is a new carbonaceous material that is closely packed into a two-dimensional honeycomb lattice structure by a single layer of carbon atoms. Before the discovery of graphene, most physicists believed that thermodynamic fluctuations did not allow any two-dimensional crystals to exist at finite temperatures. In 2004, the physicists of the University of Manchester, André Heim and Konstantin Novoselov, used a microfolitation method to prepare a carbon film with a single atomic thickness. The dimensional carbon material exhibits high crystallinity and is unusually stable, and it can exist alone. Undoubtedly, graphene is another major discovery after carbon nanotubes and fullerene spheres. Heim and Novoselov have also won the 2010 Nobel Prize for their pioneering research on two-dimensional graphene materials. Bell Physics Award. Due to the unique two-dimensional structure of graphene and excellent crystallographic structure, graphene contains rich and novel physical phenomena, which has important theoretical research and application value.
由于石墨烯的性能与其层数有密切关系，为了实现石墨烯的商业应用，低成本高产率制备层数可控的高质量石墨烯是一个非常重要的研究方向。目前，制备石墨烯的方法包括以下几种：(1)微机械剥离法，此法制得的石墨烯晶体结构完整，但是产率太低，不适合大规模生产；(2)化学气相沉积法(CVD)，此法制备的石墨烯晶体结构较完整，通过控制条件可实现层数可控，但是成本较高，制备工艺要求较高，难以实现规模生产；(3)外延生长法，该方法能够得到大面积的石墨烯，但是石墨烯薄片不易于基底分离，成本较高；(4)溶剂剥离法，此法通过将石墨与部分插层剂混合，在适当溶剂中进行剥离，该方法可得到较高质量的石墨烯，但是该方法需要长时间的超声或者球磨等处理过程，而且往往产率不高；(5)氧化还原法，该法是现阶段最常用的大量制备石墨烯的方法，但此法制得的石墨烯缺陷较多，石墨烯的导电性能较差。而且此方法很难实现层数控制，中国专利《一种层数可控的高质量石墨烯的制备方法》(CN101993061A)通过调控石墨的氧化程度，实现层数控制。但该方法使用氢氩混合气在300-1000℃的高温下还原氧化石墨，存在还原时间长，对设备要求高，反应成本高，能耗高等问题。Since the performance of graphene is closely related to the number of layers, in order to realize the commercial application of graphene, it is a very important research direction to prepare high-quality graphene with low-level and high-yield production of layers. At present, the methods for preparing graphene include the following: (1) Micromechanical stripping method, wherein the graphene crystal structure obtained by the method is complete, but the yield is too low, and is not suitable for large-scale production; (2) chemical vapor deposition method ( CVD), the crystal structure of graphene prepared by this method is relatively complete, and the number of layers can be controlled by control conditions, but the cost is high, the preparation process is high, and it is difficult to achieve scale production; (3) epitaxial growth method, the method can A large area of graphene is obtained, but the graphene sheet is not easy to be separated from the substrate, and the cost is high; (4) solvent stripping method, which can be obtained by mixing graphite and a part of the intercalating agent in a suitable solvent. Higher quality graphene, but this method requires long-term ultrasonic or ball milling treatment, and often the yield is not high; (5) redox method, which is the most commonly used method for preparing graphene at this stage. However, the graphene produced by this method has many defects, and the graphene has poor conductivity. Moreover, this method is difficult to achieve the number of layers control, the Chinese patent "a method for preparing high-quality graphene with controllable number of layers" (CN101993061A) achieves layer control by regulating the degree of oxidation of graphite. However, this method uses a hydrogen-argon mixed gas to reduce graphite oxide at a high temperature of 300-1000 ° C, which has problems of long reduction time, high requirements on equipment, high reaction cost, and high energy consumption.
因此，开发一种简单的，大规模制备层数可控的高质量石墨烯制备方法非常重要。为解决已报道方法存在的问题，本发明使用石墨为反应物质，通过在石墨层间可控***能储存锂离子的(化合、嵌入等)插层客体(如金属盐、金属氧化物，聚合物或单质等)，形成阶数可控的石墨插层化合物(GICs)；将石墨插层化合物制成电极，用作锂离子电池负 极，经过部分不可逆的电化学过程，石墨插层化合物层间的范德华力消失，转换为石墨烯，经过分散、洗涤等一系列处理，获得层数可控的石墨烯。本发明通过电化学过程使石墨的分子间作用力被破坏，不需要经过超声或者膨胀等剧烈反应过程，反应过程温和，并能精确控制石墨烯层数，得到的石墨烯片具有缺陷少，电导率高等优点，易于大规模产业化生产。Therefore, it is very important to develop a simple, large-scale preparation method for the preparation of high quality graphene with controllable number of layers. In order to solve the problems of the reported method, the present invention uses graphite as a reactive substance, through controlled insertion of a lithium ion (combination, embedding, etc.) intercalation guest (such as a metal salt, a metal oxide, a polymer) through a controlled insertion between graphite layers. Or elemental, etc., to form graphite intercalation compounds (GICs) with controllable order; graphite intercalation compounds are used as electrodes for lithium ion battery negative After a partially irreversible electrochemical process, the van der Waals force between the layers of the graphite intercalation compound disappears and is converted into graphene. After a series of treatments such as dispersion and washing, graphene with controlled layer number is obtained. The invention destroys the intermolecular force of graphite by electrochemical process, does not need to undergo a violent reaction process such as ultrasonic or expansion, has a mild reaction process, and can accurately control the number of graphene layers, and the obtained graphene sheet has few defects and conductance. High rate and other advantages, easy to large-scale industrial production.
发明内容Summary of the invention
本发明的目的在于开发一种简单的，大规模制备层数可控的高质量石墨烯制备方法。The object of the present invention is to develop a simple, large-scale preparation method for the preparation of high quality graphene having a controlled number of layers.
本发明提出一种利用电化学过程制备层数可控的高质量石墨烯的方法，具体步骤如下：The invention provides a method for preparing high quality graphene with controllable number of layers by using an electrochemical process, and the specific steps are as follows:
(1)将石墨与可以储锂的插层剂混合，制成不同阶数的石墨插层化合物(GICs)；(1) mixing graphite with an intercalant capable of storing lithium to prepare graphite intercalation compounds (GICs) of different orders;
(2)将步骤(1)所制得的石墨插层化合物在锂离子电池的电解液中作为电池负极，通过充放电过程，使石墨烯片层间的分子间作用力消失(过程如图1所示)，得到石墨烯复合物；(2) The graphite intercalation compound prepared in the step (1) is used as a battery negative electrode in the electrolyte of the lithium ion battery, and the intermolecular force between the graphene sheets disappears through the charging and discharging process (the process is as shown in FIG. 1). Show) to obtain a graphene composite;
(3)将步骤(2)得到的石墨烯复合物在溶剂中分散，通过超声方法处理，然后过滤、洗涤，得到不同层数的高质量石墨烯。其中：(3) The graphene composite obtained in the step (2) is dispersed in a solvent, treated by an ultrasonic method, and then filtered and washed to obtain high-quality graphene of different layers. among them:
所述的超声时间取决于超声波处理时的功率大小、石墨的颗粒尺寸，由于分子间作用力已被破坏，超声时间控制在30分钟以内即可(一般超声5-25分钟)，超声功率为200-2000W，频率为15-100kHz；The ultrasonic time depends on the power level during ultrasonic treatment and the particle size of graphite. Since the intermolecular force has been destroyed, the ultrasonic time can be controlled within 30 minutes (general ultrasound 5-25 minutes), and the ultrasonic power is 200. -2000W, frequency is 15-100kHz;
所述的剪切转速为10-28000rpm，剪切时间为10min-30min；The shearing speed is 10-28000 rpm, and the shearing time is 10 min-30 min;
所述的球磨转速为200-1600rpm，球磨时间为20min-3h。The ball milling speed is 200-1600 rpm, and the ball milling time is 20 min-3 h.
本发明中，步骤(1)所述的石墨插层化合物，其阶数一般控制为1到10之间的单一阶或含不同阶的化合物，根据需要通过调节石墨与插层剂的比例以及反应条件，调节生成不同阶数。In the present invention, the graphite intercalation compound described in the step (1) is generally controlled to have a single order or a compound having a different order between 1 and 10, and the ratio of the graphite to the intercalant and the reaction are adjusted as needed. Conditions, adjustments generate different orders.
本发明中，步骤(1)所述的石墨插层化合物的制备方法包括固相***、液相***、气相***方法中的一种，或其中几种方法的混合。根据反应时***物状态的不同，GICs的制备方法可分为：双室法、化学法、电化学法、混合法、加压法和熔盐法等。现将制备GICs的常用方法具体介绍如下：In the present invention, the method for preparing the graphite intercalation compound according to the step (1) includes one of solid phase insertion, liquid phase insertion, gas phase insertion, or a mixture of several of them. Depending on the state of the insert at the time of the reaction, the preparation methods of GICs can be classified into a two-chamber method, a chemical method, an electrochemical method, a mixing method, a press method, and a molten salt method. The common methods for preparing GICs are now described as follows:
1.双室法合成GICs：双室法是制备GICs的经典方法，特别适合于碱金属-GICs及金属氯化物-GICs的制备。在耐热玻璃反应器两端的反应室中，分别放置石墨和***物，抽真空熔封后，用两组电炉分别控制玻璃反应器两端反应室的温度，使Tg>Ti(石墨试样 的温度Tg>***物的温度Ti)，以保证***物能顺利地***石墨层间，同时防止生成的插层化合物在温度过高时发生分解反应；1. Double-compartment synthesis of GICs: The dual-chamber method is a classical method for the preparation of GICs, and is particularly suitable for the preparation of alkali metal-GICs and metal chloride-GICs. Graphite and insert were placed in the reaction chambers at both ends of the heat-resistant glass reactor. After vacuum sealing, the temperature of the reaction chambers at both ends of the glass reactor was controlled by two sets of electric furnaces to make Tg>Ti (graphite sample). Temperature Tg > temperature of the insert Ti) to ensure that the insert can be smoothly inserted between the graphite layers while preventing the formation of the intercalation compound from decomposing when the temperature is too high;
2.化学法合成GICs：以天然鳞片石墨和H2SO4为原料，Cl2、重铬酸盐、H2O2、HNO3等为氧化剂，通过氧化剂使石墨碳层氧化，以浓H2SO4作为主要插层剂进行插层。鳞片石墨经氧化处理后，失去π电子，阴离子进入石墨层间，形成石墨层间化合物；2. Chemical synthesis of GICs: using natural flake graphite and H 2 SO 4 as raw materials, Cl 2 , dichromate, H 2 O 2 , HNO 3, etc. as oxidants, oxidizing the graphite carbon layer by oxidizing agent to concentrate H 2 SO 4 was intercalated as the primary intercalant. After the scale graphite is oxidized, the π electrons are lost, and the anions enter the graphite layer to form a graphite intercalation compound;
3.电化学法合成GICs：电化学法合成GICs是将天然鳞片石墨和辅助阳极一起构成阳极室，插层剂溶液作电解液，通直流或脉冲电流，进行阳极氧化，脱酸、水洗、脱水干燥得到的。这是一种利用电化学反应将***物以离子的形式***石墨层间而制备GICs的方法；3. Electrochemical synthesis of GICs: Electrochemical synthesis of GICs is the combination of natural flake graphite and auxiliary anodes into the anode chamber, the intercalant solution as the electrolyte, through the direct current or pulse current, anodizing, deacidification, water washing, dehydration Dried out. This is a method for preparing GICs by inserting an insert into the graphite layer in the form of ions by an electrochemical reaction;
4.混合法合成GICs：这是一种直接将石墨与***物混合，然后在流动性保护气氛下或在封闭***中进行热处理而制备GICs的方法；4. Mixed method for synthesizing GICs: This is a method for preparing GICs by directly mixing graphite with an insert and then performing heat treatment under a fluid protective atmosphere or in a closed system;
5.加压法合成GICs：将碱土金属和稀土金属粉末等与石墨基体混合后在加压条件下反应生成M-GICs；5. Synthesis of GICs by pressurization: mixing alkaline earth metal and rare earth metal powder with graphite matrix and reacting under pressure to form M-GICs;
6.熔盐法(也称为混合液相法)合成GICs：熔盐法是基于各组分共晶可使体系熔点降低(低于各组分的熔点)的性质而提出来的，是一种可同时将两种或两种以上物质(必须能形成熔融盐体系)***石墨层间的制备三元或多元GICs的方法。该方法使原来需要较高的反应温度才能***石墨层间的反应物质在较低的反应温度下就可***石墨层间，因而具有重要的实用价值。6. Molten salt method (also known as mixed liquid phase method) synthesis of GICs: molten salt method is based on the properties of the eutectic of each component can reduce the melting point of the system (below the melting point of each component), is a A method of preparing ternary or multi-component GICs by inserting two or more substances (which must form a molten salt system) into a graphite layer at the same time. The method allows the reaction material which originally needs a higher reaction temperature to be inserted into the graphite layer to be inserted between the graphite layers at a lower reaction temperature, and thus has important practical value.
此外合成GICs方法还有光化学法、催化剂法、***法等，这些合成方法，各有其优点和不足之处，合成对象亦不尽相同，因较少采用，这里不作详细阐述。In addition, the methods for synthesizing GICs include photochemical method, catalyst method, explosion method, etc. These synthetic methods each have their own advantages and disadvantages, and the synthetic objects are also different. Because they are less used, they will not be elaborated here.
本发明中，步骤(1)所述的插层主体为，石墨包括但不仅限于天然石墨，改性石墨，人造石墨(如HOPG、沥青基炭纤维、气相生长炭纤维、聚丙烯腈炭纤维等等)，石墨化的碳材料具有层状结构的石墨中的至少一种。这些材料部分或全部具有石墨结构，层面内碳原子以SP2杂化轨道电子形成共价键，同时各个碳原子又与2pZ轨道电子形成金属键，形牢固的六角网状平面炭层。In the present invention, the intercalation body described in the step (1) includes, but is not limited to, natural graphite, modified graphite, artificial graphite (such as HOPG, pitch-based carbon fiber, vapor-grown carbon fiber, polyacrylonitrile carbon fiber, etc.). And the like, the graphitized carbon material has at least one of graphite having a layered structure. Some or all of these materials have a graphite structure in which carbon atoms in the layer form covalent bonds with SP 2 hybrid orbital electrons, and each carbon atom forms a metal bond with 2pZ orbital electrons, forming a solid hexagonal network planar carbon layer.
本发明中，步骤(1)所述的插层剂为金属盐、金属氧化物、聚合物、单质中的一种，或其中几种的混合体。具体物质见表1，具体物质包括但不仅限于表1中所述物质。In the present invention, the intercalation agent described in the step (1) is one of a metal salt, a metal oxide, a polymer, a simple substance, or a mixture of several of them. The specific substances are shown in Table 1. Specific substances include, but are not limited to, the substances described in Table 1.
本发明中，步骤(2)所述的充放电过程可以在放电状态下停止，也可以在充电状态下停止。In the present invention, the charge and discharge process described in the step (2) may be stopped in a discharged state or may be stopped in a charged state.
本发明中，步骤(3)所述的分散过程，所用溶剂包括水和乙醇、苯、甲苯等常用有机溶剂。In the present invention, in the dispersion process described in the step (3), the solvent used includes water and a common organic solvent such as ethanol, benzene or toluene.
本发明制备方法得到的石墨烯，其石墨烯层数为1-10层，石墨晶格缺陷少，呈现出 比较完整的六边形，石墨烯表面不含环氧基、羧基、羟基等含氧基团；电子迁移率超过3000cm2/Vs，石墨烯导电性好。The graphene obtained by the preparation method of the invention has a graphene layer number of 1-10 layers, a graphite lattice defect is small, and a relatively complete hexagon is formed, and the graphene surface does not contain an epoxy group, a carboxyl group, a hydroxyl group or the like. The group; the electron mobility exceeds 3000 cm 2 /Vs, and the graphene has good conductivity.
附图说明DRAWINGS
图1是本发明通过充放电使分子间作用力被破坏的过程图。BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the process of destroying intermolecular forces by charge and discharge according to the present invention.
图2是本发明所制备的二阶氯化铁氯化铜石墨插层化合物的XRD。2 is an XRD of a second-order ferric chloride copper chloride graphite intercalation compound prepared by the present invention.
图3是本发明所制备的2层石墨烯的透射电镜(TEM)图片。Figure 3 is a transmission electron microscope (TEM) image of a 2-layer graphene prepared by the present invention.
图4是本发明所制备的2层石墨烯的拉曼(Raman)光谱。4 is a Raman spectrum of a 2-layer graphene prepared by the present invention.
图5是本发明所制备的2层石墨烯的电子输运测试结果。Figure 5 is a graph showing the results of electron transport test of the 2-layer graphene prepared by the present invention.
具体实施方式detailed description
从以下实施例可以更好地理解本发明，但本发明不仅仅局限于以下实施例。The invention can be better understood from the following examples, but the invention is not limited to the following examples.
术语说明Terminology
除非另外定义，否则本文中所用的全部技术与科学术语均具有如本发明所属领域的普通技术人员通常理解的相同含义。All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined.
如本文所用，在提到具体列举的数值中使用时，术语“约”意指该值可以从列举的值变动不多于1％。例如，如本文所用，表述“约100”包括99和101和之间的全部值(例如，99.1、99.2、99.3、99.4等)。As used herein, when used in reference to a particular recited value, the term "about" means that the value can vary by no more than 1% from the recited value. For example, as used herein, the expression "about 100" includes all values between 99 and 101 and (eg, 99.1, 99.2, 99.3, 99.4, etc.).
如本文所用，术语“含有”或“包括(包含)”可以是开放式、半封闭式和封闭式的。换言之，所述术语也包括“基本上由…构成”、或“由…构成”。As used herein, the terms "containing" or "including" may be open, semi-closed, and closed. In other words, the terms also include "consisting essentially of," or "consisting of."
石墨插层化合物石墨插层化合物就是用物理或化学方法使异类原子、分子或离子***原子层间而生成的新型化合物，亦称层间化合物或夹层化合物。石墨插层化合物可以生成不同阶结构的层间化合物。石墨插层化合物的阶结构常用阶数来表示，每隔一层碳原子平面，***一层***物而形成的石墨插层化合物称为一阶石墨插层化合物。依此类推，每隔n层碳原子平面，***一层***物而形成的石墨插层化合物称为n阶石墨插层化合物。Graphite Intercalation Compounds Graphite intercalation compounds are novel compounds formed by physically or chemically intercalating heteroatoms, molecules or ions between atomic layers, also known as interlayer compounds or interlayer compounds. Graphite intercalation compounds can form interlaminar compounds of different order structures. The order structure of the graphite intercalation compound is usually expressed by the order, and the graphite intercalation compound formed by inserting a layer of intercalation every other layer of carbon atoms is called a first-order graphite intercalation compound. By analogy, a graphite intercalation compound formed by inserting a layer of intercalation every n-layer carbon atom plane is called an n-th order graphite intercalation compound.
石墨烯Graphene
石墨烯的碳原子排列与石墨的单原子层相同，是碳原子以sp2杂化轨道呈蜂巢晶格排列构成的碳原子单层二维晶体。由一层石墨烯组成的即为单层石墨烯，由2层石墨烯 堆垛构成的二维碳材料称为双层石墨烯，由3层至9层石墨烯堆垛构成的二维碳材料称为少层石墨烯。Graphene has the same carbon atom arrangement as the monoatomic layer of graphite, and is a single-layer two-dimensional crystal of carbon atoms composed of carbon atoms arranged in a honeycomb lattice in a sp2 hybrid orbital. A layer of graphene composed of a layer of graphene, composed of 2 layers of graphene The two-dimensional carbon material composed of stacking is called double-layer graphene, and the two-dimensional carbon material composed of stacks of three to nine layers of graphene is called a small layer of graphene.
本发明所制得的石墨烯层数与石墨插层化合物前驱体的阶数一致。如一阶石墨插层化合物可制得单层石墨烯，二阶石墨插层化合物可制得双层石墨烯等等。The number of graphene layers produced by the present invention is consistent with the order of the graphite intercalation compound precursor. For example, a first-order graphite intercalation compound can produce a single-layer graphene, and a second-order graphite intercalation compound can produce a bi-layer graphene or the like.
本发明的主要优点在于：The main advantages of the invention are:
(1)本发明中，使用石墨为反应物质，通过在石墨层间可控***能储存锂离子的插层客体，形成阶数可控的石墨插层化合物，由此可以实现石墨烯层数的精确控制。(1) In the present invention, graphite is used as a reaction substance, and a layer of intercalated guest capable of storing lithium ions can be controlledly inserted between graphite layers to form a graphite intercalation compound whose order is controllable, thereby realizing the number of graphene layers. Precise control.
(2)通过电化学过程使石墨的分子间作用力被破坏，不需要经过超声或者膨胀等剧烈反应过程，反应过程温和，得到的石墨烯片具有缺陷少，电导率高等优点，易于大规模产业化生产。(2) The intermolecular force of graphite is destroyed by electrochemical process, which does not require a violent reaction process such as ultrasonic or expansion, and the reaction process is mild, and the obtained graphene sheet has the advantages of less defects and high electrical conductivity, and is easy to be mass-produced. Production.
下面结合具体实施例，进一步阐述本发明。应理解，这些实施例仅用于说明本发明而不用于限制本发明的范围。下列实施例中未注明具体条件的实验方法，通常按照常规条件，或按照制造厂商所建议的条件。除非另外说明，否则百分比和份数是重量百分比和重量份数。The invention is further illustrated below in conjunction with specific embodiments. It is to be understood that the examples are not intended to limit the scope of the invention. The experimental methods in the following examples which do not specify the specific conditions are usually in accordance with conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are by weight and parts by weight.
以下实施例中所用的实验材料和试剂如无特别说明均可从市售渠道获得。The experimental materials and reagents used in the following examples are available from commercially available sources unless otherwise specified.
实施例1：Example 1:
称取6g石墨，3.24g无水氯化铁，2.69g无水氯化铜充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，400℃处理6个小时。所得产品用去离子水洗至洗涤液中无Fe3+、Cu2+。水洗后的样品在真空烘箱中120℃干燥10小时，制得二阶氯化铁氯化铜石墨插层化合物。(详见图1)6 g of graphite, 3.24 g of anhydrous ferric chloride, 2.69 g of anhydrous copper chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 400 ° C for 6 hours. The obtained product was washed with deionized water until there was no Fe 3+ or Cu 2+ in the washing liquid. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours to obtain a second-order ferric chloride copper chloride graphite intercalation compound. (See Figure 1 for details)
将上述所制二阶氯化铁氯化铜石墨插层化合物直接压在泡沫镍网上制成电极，之后放置在80℃真空烘箱中干燥12小时，以此作为锂离子电池的工作电极。在手套箱中按照正极/隔膜/负极的顺序组装进行单电极测试。单电极测试以锂片为负极，1M LiPF6·EC/DEC/DMC(体积比为1:1:1)为电解液，隔膜采用商用锂离子电池隔膜，组装成电池。电池工作区间为0～3.0V，充放电电流为100mA/g，首圈放电到0V，充回到3V后，将电池拆开，将石墨插层化合物电极分散到水中，超声分散10分钟，水洗、稀盐酸洗之后过滤，即可制得2层的石墨烯(详见图2)，这样制得的石墨烯缺陷很少(详见图3)，导电性很优异(详见图4)。 The second-order ferric chloride copper chloride graphite intercalation compound prepared above was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery. Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ·EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery. The battery working range is 0 ~ 3.0V, the charge and discharge current is 100mA / g, the first ring discharge to 0V, after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 10 minutes, water washing After washing with dilute hydrochloric acid, two layers of graphene can be obtained (see Figure 2 for details), so that the graphene has few defects (see Figure 3) and the conductivity is excellent (see Figure 4).
实施例2：Example 2:
称取6g石墨，3.24g无水氯化铁，2.69g无水氯化铜充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，400℃处理6个小时。所得产品用去离子水洗至洗涤液中无Fe3+、Cu2+。水洗后的样品在真空烘箱中120℃干燥10小时，制得二阶氯化铁氯化铜石墨插层化合物。(详见图1)6 g of graphite, 3.24 g of anhydrous ferric chloride, 2.69 g of anhydrous copper chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 400 ° C for 6 hours. The obtained product was washed with deionized water until there was no Fe 3+ or Cu 2+ in the washing liquid. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours to obtain a second-order ferric chloride copper chloride graphite intercalation compound. (See Figure 1 for details)
将上述所制二阶氯化铁氯化铜石墨插层化合物直接压在泡沫镍网上制成电极，之后放置在80℃真空烘箱中干燥12小时，以此作为锂离子电池的工作电极。在手套箱中按照正极/隔膜/负极的顺序组装进行单电极测试。单电极测试以锂片为负极，1M LiPF6·EC/DEC/DMC(体积比为1:1:1)为电解液，隔膜采用商用锂离子电池隔膜，组装成电池。电池工作区间为0～3.0V，充放电电流为100mA/g，首圈放电到0V，充回到1.5V，将电池拆开，将石墨插层化合物电极分散到水中，超声分散10分钟，水洗、稀盐酸洗之后过滤，即可制得2层的石墨烯。The second-order ferric chloride copper chloride graphite intercalation compound prepared above was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery. Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ·EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery. The battery working range is 0~3.0V, the charging and discharging current is 100mA/g, the first ring discharges to 0V, and the battery is charged back to 1.5V. The battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonically dispersed for 10 minutes, and washed. After washing with dilute hydrochloric acid and filtering, two layers of graphene can be obtained.
实施例3：Example 3:
称取6g石墨，3.24g无水氯化铁，2.69g无水氯化铜充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，400℃处理6个小时。所得产品用去离子水洗至洗涤液中无Fe3+、Cu2+。水洗后的样品在真空烘箱中120℃干燥10小时，制得二阶氯化铁氯化铜石墨插层化合物。(详见图1)6 g of graphite, 3.24 g of anhydrous ferric chloride, 2.69 g of anhydrous copper chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 400 ° C for 6 hours. The obtained product was washed with deionized water until there was no Fe 3+ or Cu 2+ in the washing liquid. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours to obtain a second-order ferric chloride copper chloride graphite intercalation compound. (See Figure 1 for details)
将上述所制二阶氯化铁氯化铜石墨插层化合物直接压在泡沫镍网上制成电极，之后放置在80℃真空烘箱中干燥12小时，以此作为锂离子电池的工作电极。在手套箱中按照正极/隔膜/负极的顺序组装进行单电极测试。单电极测试以锂片为负极，1M LiPF6·EC/DEC/DMC(体积比为1:1:1)为电解液，隔膜采用商用锂离子电池隔膜，组装成电池。电池工作区间为0～3.0V，充放电电流为100mA/g，在0-3V区间循环5圈后，将电池拆开，将石墨插层化合物电极分散到水中，超声分散25分钟，水洗、稀盐酸洗之后过滤，即可制得2层的石墨烯。The second-order ferric chloride copper chloride graphite intercalation compound prepared above was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery. Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ·EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery. The battery working range is 0 ~ 3.0V, the charge and discharge current is 100mA / g, after circulating 5 times in the 0-3V interval, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonically dispersed for 25 minutes, washed, diluted After washing with hydrochloric acid, filtration was carried out to obtain two layers of graphene.
实施例4：Example 4:
称取8g石墨，5.36g无水氯化铁，充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，550℃处理12个小时。所得产品用去离子水洗至洗涤液中无Fe3+、Cu2+。水洗后的样品在真空烘箱中120℃干燥10小时，制得四阶氯化铁石墨插层化合物。8 g of graphite and 5.36 g of anhydrous ferric chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 550 ° C for 12 hours. The obtained product was washed with deionized water until there was no Fe 3+ or Cu 2+ in the washing liquid. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours to prepare a fourth-order ferric chloride graphite intercalation compound.
将上述所制四阶氯化铁石墨插层化合物直接压在泡沫镍网上制成电极，之后放置在 80℃真空烘箱中干燥12小时，以此作为锂离子电池的工作电极。在手套箱中按照正极/隔膜/负极的顺序组装进行单电极测试。单电极测试以锂片为负极，1M LiPF6·EC/DEC/DMC(体积比为1:1:1)为电解液，隔膜采用商用锂离子电池隔膜，组装成电池。电池工作区间为0～3.0V，充放电电流为100mA/g，首圈放电到0V，充回到3V后，将电池拆开，将石墨插层化合物电极分散到水中，超声分散20分钟，水洗、稀盐酸洗之后过滤，即可制得四层的石墨烯。The above-prepared fourth-order ferric chloride graphite intercalation compound was directly pressed on a foamed nickel mesh to form an electrode, which was then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode for a lithium ion battery. Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ·EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery. The battery working range is 0 ~ 3.0V, the charge and discharge current is 100mA / g, the first ring discharge to 0V, after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 20 minutes, water washing After washing with dilute hydrochloric acid and filtering, four layers of graphene can be obtained.
实施例5：Example 5:
称取12g石墨，5.36g无水氯化铁，充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，600℃处理12个小时。所得产品用去离子水洗至洗涤液中无Fe3+、Cu2+。水洗后的样品在真空烘箱中120℃干燥10小时，制得六阶氯化铁石墨插层化合物。12 g of graphite and 5.36 g of anhydrous ferric chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 600 ° C for 12 hours. The obtained product was washed with deionized water until there was no Fe 3+ or Cu 2+ in the washing liquid. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours to obtain a sixth-order ferric chloride graphite intercalation compound.
将上述所制四阶氯化铁石墨插层化合物直接压在泡沫镍网上制成电极，之后放置在80℃真空烘箱中干燥12小时，以此作为锂离子电池的工作电极。在手套箱中按照正极/隔膜/负极的顺序组装进行单电极测试。单电极测试以锂片为负极，1M LiPF6·EC/DEC/DMC(体积比为1:1:1)为电解液，隔膜采用商用锂离子电池隔膜，组装成电池。电池工作区间为0～3.0V，充放电电流为100mA/g，首圈放电到0V，充回到3V后，将电池拆开，将石墨插层化合物电极分散到水中，超声分散10分钟，水洗、稀盐酸洗之后过滤，即可制得六层的石墨烯。The above-prepared fourth-order ferric chloride graphite intercalation compound was directly pressed on a foamed nickel mesh to form an electrode, which was then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode for a lithium ion battery. Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ·EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery. The battery working range is 0 ~ 3.0V, the charge and discharge current is 100mA / g, the first ring discharge to 0V, after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 10 minutes, water washing After washing with dilute hydrochloric acid and filtering, six layers of graphene can be obtained.
实施例6：Example 6
称取6g石墨，4.33g无水氯化钴，充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，700℃处理3个小时。所得产品用去离子水洗至洗涤液中无Fe3+、Cu2+。水洗后的样品在真空烘箱中120℃干燥10小时，制得三阶四阶混阶的氯化钴石墨插层化合物。6 g of graphite and 4.33 g of anhydrous cobalt chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 700 ° C for 3 hours. The obtained product was washed with deionized water until there was no Fe 3+ or Cu 2+ in the washing liquid. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours to prepare a third-order fourth-order mixed-order cobalt chloride graphite intercalation compound.
将上述所制混阶的氯化钴石墨插层化合物直接压在泡沫镍网上制成电极，之后放置在80℃真空烘箱中干燥12小时，以此作为锂离子电池的工作电极。在手套箱中按照正极/隔膜/负极的顺序组装进行单电极测试。单电极测试以锂片为负极，1M LiPF6·EC/DEC/DMC(体积比为1:1:1)为电解液，隔膜采用商用锂离子电池隔膜，组装成电池。电池工作区间为0～3.0V，充放电电流为100mA/g，首圈放电到0V，充回到3V后，将电池拆开，将石墨插层化合物电极分散到水中，超声分散10分钟，水洗、稀盐酸洗之后过滤，即可制得三层、四层为主的石墨烯。 The above-mentioned mixed-stage cobalt chloride graphite intercalation compound was directly pressed on a foamed nickel mesh to form an electrode, and then placed in a vacuum oven at 80 ° C for 12 hours to serve as a working electrode of a lithium ion battery. Single electrode testing was performed in the glove box in the order of positive/separator/negative. The single electrode test uses a lithium plate as a negative electrode, 1M LiPF 6 ·EC/DEC/DMC (volume ratio 1:1:1) as an electrolyte, and a separator using a commercial lithium ion battery separator to assemble a battery. The battery working range is 0 ~ 3.0V, the charge and discharge current is 100mA / g, the first ring discharge to 0V, after charging back to 3V, the battery is disassembled, the graphite intercalation compound electrode is dispersed into water, ultrasonic dispersion for 10 minutes, water washing After washing with dilute hydrochloric acid, the three-layer and four-layer graphene can be obtained.
对比例1Comparative example 1
称取6g石墨，0.2无水氯化铁，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，400℃处理6个小时。所得产品用去离子水洗至洗涤液中无Fe3+。水洗后的样品在真空烘箱中120℃干燥10小时。6 g of graphite, 0.2 anhydrous ferric chloride were weighed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 400 ° C for 6 hours. The resulting product was washed with deionized water until there was no Fe 3+ in the wash. The washed sample was dried in a vacuum oven at 120 ° C for 10 hours.
由于氯化铁的用量过少，无法形成阶数清晰的插层化合物，故而无法制得石墨烯。对比例2Since the amount of ferric chloride used is too small to form an intercalation compound having a clear order, graphene cannot be obtained. Comparative example 2
称取6g石墨，3.24g无水氯化铁，2.69g无水氯化铜充分混合后，80℃真空烘箱中干燥8小时，干燥后的样品在反应釜中密封，200℃处理6个小时。6 g of graphite, 3.24 g of anhydrous ferric chloride, 2.69 g of anhydrous copper chloride were weighed and thoroughly mixed, and dried in a vacuum oven at 80 ° C for 8 hours. The dried sample was sealed in a reaction vessel and treated at 200 ° C for 6 hours.
此对比例中反应温度过低，无法制得石墨插层化合物，故而无法制得石墨烯。In the comparative example, the reaction temperature was too low, and a graphite intercalation compound could not be obtained, so that graphene could not be obtained.
表1石墨插层化合物客体材料列表Table 1 List of graphite intercalation compound guest materials
Figure PCTCN2016106625-appb-000001
Figure PCTCN2016106625-appb-000001
Figure PCTCN2016106625-appb-000002
Figure PCTCN2016106625-appb-000002
Figure PCTCN2016106625-appb-000003
Figure PCTCN2016106625-appb-000003
Figure PCTCN2016106625-appb-000004
Figure PCTCN2016106625-appb-000004
在本发明提及的所有文献都在本申请中引用作为参考，就如同每一篇文献被单独引用作为参考那样。此外应理解，在阅读了本发明的上述讲授内容之后，本领域技术人员可以对本发明作各种改动或修改，这些等价形式同样落于本申请所附权利要求书所限定的范围。 All documents mentioned in the present application are hereby incorporated by reference in their entirety in their entireties in the the the the the the the the In addition, it should be understood that various modifications and changes may be made by those skilled in the art in the form of the appended claims.

Claims (14)

  1. 一种利用电化学过程制备层数可控的高质量石墨烯的方法，其特征在于，具体步骤如下：A method for preparing high quality graphene with controlled number of layers by using an electrochemical process, characterized in that the specific steps are as follows:
    (1)将石墨与可以储锂的插层剂混合，制成不同阶数的石墨插层化合物；(1) mixing graphite with an intercalant capable of storing lithium to prepare graphite intercalation compounds of different orders;
    (2)将步骤(1)所制得的石墨插层化合物在锂离子电池的电解液中作为电池负极，通过充放电过程，使石墨烯片层间的分子间作用力消失，得到石墨烯复合物；(2) The graphite intercalation compound prepared in the step (1) is used as a battery negative electrode in an electrolyte solution of a lithium ion battery, and the intermolecular force between the graphene sheets disappears through a charge and discharge process to obtain a graphene composite. Object
    (3)将步骤(2)得到的石墨烯复合物在溶剂中分散，通过超声方法处理，然后过滤、洗涤，得到不同层数的高质量石墨烯。(3) The graphene composite obtained in the step (2) is dispersed in a solvent, treated by an ultrasonic method, and then filtered and washed to obtain high-quality graphene of different layers.
  2. 根据权利要求1所述的方法，其特征在于，石墨插层化合物的插层主体为石墨；插层客体即插层剂为可逆或部分可逆储存锂离子的物质，插层剂包括金属盐、金属氧化物、聚合物、单质中的一种，或其中几种的混合体。The method according to claim 1, wherein the intercalation body of the graphite intercalation compound is graphite; the intercalation agent is an intercalant which is a substance which reversibly or partially reversibly stores lithium ions, and the intercalant comprises a metal salt and a metal. One of an oxide, a polymer, a simple substance, or a mixture of several of them.
  3. 根据权利要求1或2所述的方法，其特征在于，所述石墨为天然石墨、人造石墨、改性石墨、石墨化的碳材料具有层状结构的石墨中的至少一种。The method according to claim 1 or 2, wherein the graphite is at least one of natural graphite, artificial graphite, modified graphite, and graphitized carbon material having a layered structure of graphite.
  4. 根据权利要求1或2所述的方法，其特征在于，所述的石墨插层化合物，阶数为1到10的单一阶或含不同阶的化合物。The method according to claim 1 or 2, wherein the graphite intercalation compound has a single order of 1 to 10 or a compound having a different order.
  5. 根据权利要求1所述的方法，其特征在于，石墨插层化合物的制备方法包括固相***、液相***、气相***方法中的一种，或其中几种方法的混合。The method according to claim 1, wherein the method for preparing the graphite intercalation compound comprises one of a solid phase insertion, a liquid phase insertion, a gas phase insertion method, or a mixture of several of the methods.
  6. 根据权利要求1所述的方法，其特征在于，充放电过程在放电状态下停止，或者在充电状态下停止。The method according to claim 1, wherein the charging and discharging process is stopped in a discharged state or stopped in a charged state.
  7. 根据权利要求1所述的方法，其特征在于，分散所用溶剂为水和乙醇、苯或甲苯。The method according to claim 1, wherein the solvent used for the dispersion is water and ethanol, benzene or toluene.
  8. 根据权利要求1所述的方法，其特征在于，所制备的石墨烯层数为1-10层，石墨晶格缺陷少。The method according to claim 1, wherein the number of graphene layers produced is 1-10 layers, and the graphite lattice defects are small.
  9. 根据权利要求1所述的方法，其特征在于，所述的超声时间为30分钟以内，超声功率为200-2000W，频率为15-100kHz；The method according to claim 1, wherein the ultrasonic time is within 30 minutes, the ultrasonic power is 200-2000 W, and the frequency is 15-100 kHz;
    所述的剪切转速为10-28000rpm，剪切时间为10min-30min；The shearing speed is 10-28000 rpm, and the shearing time is 10 min-30 min;
    所述的球磨转速为200-1600rpm，球磨时间为20min-3h。The ball milling speed is 200-1600 rpm, and the ball milling time is 20 min-3 h.
  10. 根据权利要求1所述的方法，其特征在于，所述步骤(1)中，所述石墨与插层剂的质量比为0.1-20，较佳地为0.3-15，更佳地为0.4-10。The method according to claim 1, wherein in the step (1), the mass ratio of the graphite to the intercalant is from 0.1 to 20, preferably from 0.3 to 15, more preferably from 0.4 to 1. 10.
  11. 根据权利要求1所述的方法，其特征在于，所述步骤(2)中，所述充电电压范围为0.1-5V，较佳地为2-3V。The method according to claim 1, wherein in the step (2), the charging voltage ranges from 0.1 to 5 V, preferably from 2-3 V.
  12. 根据权利要求1所述的方法，其特征在于，所述步骤(2)中，所述放电电压范围 为0.1-1V，较佳地为0.2-0.6V，更佳地为0.3-0.5V。The method according to claim 1, wherein in said step (2), said discharge voltage range It is from 0.1 to 1 V, preferably from 0.2 to 0.6 V, more preferably from 0.3 to 0.5 V.
  13. 根据权利要求1所述的方法，其特征在于，所述插层剂选自下组：金属氯化物、单质、氧化物、有机物、或其组合。The method of claim 1 wherein the intercalant is selected from the group consisting of metal chlorides, simple substances, oxides, organics, or combinations thereof.
  14. 根据权利要求1所述的方法，其特征在于，所述插层剂选自如表1所示的插层化合物客体材料。 The method of claim 1 wherein said intercalant is selected from the group consisting of intercalation compound guest materials as shown in Table 1.
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CN104003373A (en) * 2013-02-21 2014-08-27 海洋王照明科技股份有限公司 Graphene material and preparation method thereof
CN105271205A (en) * 2015-11-20 2016-01-27 复旦大学 Method for preparing layer-number-controllable high-quality graphene through electrochemical process

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CN112978721A (en) * 2019-12-02 2021-06-18 中国科学院上海硅酸盐研究所 Method for preparing high-quality graphene by double-pulse electrochemical technology
CN115417401A (en) * 2022-05-12 2022-12-02 太原理工大学 Method for preparing graphene by recoverable low-temperature molten salt

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