WO2015180189A1

WO2015180189A1 - Carbon-supported nano silicon particle structure, and preparation method and use thereof

Info

Publication number: WO2015180189A1
Application number: PCT/CN2014/079023
Authority: WO
Inventors: 牛春明; 张翼; 姜怡喆
Original assignee: 西安交通大学
Priority date: 2014-05-30
Filing date: 2014-05-30
Publication date: 2015-12-03

Abstract

A carbon-supported nano silicon particle structure, and a preparation method and use thereof. The main structure is that partial silicon atoms in nano silicon particles form a silicon-carbon chemical bond with carbon on an interface; and more than 50% of the nano silicon particles are anchored on an a-b base plane of the carbon through the silicon-carbon chemical bond, comprising mixing nano SiO₂, a metal magnesium powder and a carbon support, wherein the mixing method comprises direct mixing or loading the nano SiO₂ onto a surface of the carbon support, and then mixing same with the magnesium powder; then using a ball mill for ball milling to further mix same uniformly under an inert gas atmosphere or vacuum; heating the mixture under the inert atmosphere so that magnesium chemically reacts with SiO₂, and the SiO₂ is reduced to silicon; removing the reaction by-product MgO, unreacted magnesium and soluble impurities by acid pickling; and heating under the inert gas or vacuum condition so that the nano silicon particles react with the carbon on the interface, and the nano silicon particles are fixed on the surface of the carbon through chemical bonding, which are easy and feasible, lower in cost and suitable for industrial production.

Description

说明书 Description

一种碳负载的纳米硅颗粒结构及其制备方法和应用技术领域 Carbon-loaded nano silicon particle structure, preparation method and application thereof

本发明属于锂离子电池技术领域，尤其涉及一种碳负载纳米硅颗粒结构及其制备方法和应用。 The invention belongs to the technical field of lithium ion batteries, and in particular relates to a carbon-loaded nano silicon particle structure and a preparation method and application thereof.

背景技术 Background technique

锂离子电池由于具有能量密度高、工作电压高、循环寿命长、自放电率低、工作温度范围广、无记忆效应和无环境污染等优点，已经成为各种便携式电子设备和电动工具的首选电源，大规模应用于手机、数码照相机、笔记本电脑等新兴工业技术领域。近年来，混合动力汽车和全电动汽车的快速发展对锂离子电池的能量密度及其它性能提出了越来越高的要求。在锂离子电池的结构中，电极材料是影响锂离子电池性能的重要因素，而当前商业化应用的石墨类材料在比容量、比能量等方面已经不能满足高能量密度锂离子电池负极材料的需要。因此，开发新型高比容量、高稳定性、低成本的锂离子电池负极材料显得尤为迫切。 Lithium-ion batteries have become the preferred power source for various portable electronic devices and power tools due to their high energy density, high operating voltage, long cycle life, low self-discharge rate, wide operating temperature range, no memory effect and no environmental pollution. Large-scale application in emerging industrial technologies such as mobile phones, digital cameras, and notebook computers. In recent years, the rapid development of hybrid and all-electric vehicles has placed increasing demands on the energy density and other properties of lithium-ion batteries. In the structure of lithium-ion batteries, electrode materials are important factors affecting the performance of lithium-ion batteries, and the graphite materials currently used in commercial applications cannot meet the needs of high-energy-density lithium-ion battery anode materials in terms of specific capacity and specific energy. . Therefore, it is particularly urgent to develop a new type of lithium ion battery anode material with high specific capacity, high stability and low cost.

在目前研究的锂离子电池负极材料体系中，硅具有最高的理论比容量 (4200 mAh/g)，安全性好，是非常具有潜力的高性能锂离子电池负极材料。然而，硅在充放电过程中伴随巨大的体积变化 (可达 400%)，容易引起硅颗粒的破碎、粉化，并与电极材料失去电接触，从而造成电极的可逆容量迅速衰减，表现为较差的循环稳定性。此外，硅是一种半导体材料，其本征电导率仅为 6. 7 X 10-4 S/cm , 在作为电极材料时需要加入导电剂。为此，研究者提出了两个方法来解决上述问题：一是制备纳米尺度的硅或多孔硅，从而缓解硅的体积效应在硅材料中引入导电性好且体积效应小的活性或非活性物质制备复合物电极，从而缓冲硅在电化学反应过程中的应力作用，并提高材料的电导率。目前，纳米硅 /金属复合负极材料和纳米硅 /碳复合负极材料是研究的热点。但是对于硅 / 碳复合电极材料，纳米硅颗粒在电化学反应条件下容易从碳的疏水基面（a-b plane)剥离、迁移和凝聚，导致电极性能下降，而目前还缺乏对纳米硅与碳基体界面深入细致的研究和了解，而且纳米硅与碳材料的复合歩骤较多，另外纳米硅制备成本高，价格昂贵（粒径 80nm左右的高纯硅价格为 0. 6-0. 9万元 /Kg, 粒径 30nm左右的高纯硅价格为 1. 0-1. 5万元 /Kg)，这些因素限制了硅基负极材料的应用。因此，发明低成本的硅 /碳复合负极材料的制备方法，了解纳米硅与碳基体的界面结构和两者相互作用的机理，对于在石墨疏水基面稳定纳米硅，最终设计和制备低成本、大容量、高功率和高循环次数的纳米硅复合物电极具有很重要的意义。 Among the lithium ion battery anode materials currently studied, silicon has the highest theoretical specific capacity (4200 mAh/g) and is safe. It is a very high-performance lithium ion battery anode material. However, silicon undergoes a large volume change (up to 400%) during charge and discharge, which easily causes the silicon particles to break and chalk, and loses electrical contact with the electrode material, resulting in rapid decay of the reversible capacity of the electrode. Poor cyclic stability. Further, silicon is a semiconductor material having an intrinsic conductivity of only 6. 7 X 10-4 S/cm, and a conductive agent is required as an electrode material. To this end, the researchers proposed two methods to solve the above problems: First, the preparation of nano-scale silicon or porous silicon, thereby alleviating the volume effect of silicon The composite electrode is prepared by introducing an active or inactive material having good conductivity and small volume effect into the silicon material, thereby buffering the stress of the silicon during the electrochemical reaction and improving the electrical conductivity of the material. At present, nano-silicon/metal composite anode materials and nano-silicon/carbon composite anode materials are the research hotspots. However, for silicon/carbon composite electrode materials, nano-silicon particles are easily stripped, migrated and agglomerated from the hydrophobic ab plane under electrochemical reaction conditions, resulting in a decrease in electrode performance, but there is currently a lack of nano-silicon and carbon matrix. The smear of the high-purity silicon with a particle size of about 0. 6-0. /Kg, the price of high-purity silicon with a particle size of about 30 nm is 1. 0-1. 5 million / Kg), these factors limit the application of silicon-based anode materials. Therefore, the invention discloses a method for preparing a low-cost silicon/carbon composite anode material, understands the interface structure of the nano-silicon and the carbon matrix, and the mechanism of interaction between the two, and stabilizes the nano-silicon on the graphite hydrophobic surface, and finally designs and prepares a low-cost, Nano-silicon composite electrodes with large capacity, high power and high cycle times are of great significance.

国内外研究现状综述： Summary of research status at home and abroad:

硅理论比容量很高（4200 mAh/g) , 作为锂离子电池负极材料具有巨大潜力。但是硅在嵌锂的过程中发生非常显著的体积膨胀，由此产生的机械应力使电极的结构被破坏，造成电极的循环性能迅速下降，且硅的本征电导率不高，限制了它的商业化应用 [1-2]。为了解决上述问题，科研工作者们做了很多的研究和探索，主要可归纳为两个方面：一是将硅制成纳米结构或者多孔结构，从而缓解硅的体积效应；二是向硅中引入高导电碳材料或引入第二金属相，不仅能够有效地缓冲硅在体积变化过程中产生的应力，而且能够增加电极材料的电导率。 Silicon has a high theoretical specific capacity (4200 mAh/g) and has great potential as a negative electrode material for lithium ion batteries. However, silicon undergoes a very significant volume expansion during the process of lithium intercalation. The resulting mechanical stress causes the structure of the electrode to be destroyed, resulting in a rapid decrease in the cycle performance of the electrode, and the intrinsic conductivity of silicon is not high, which limits its Commercial application [1-2]. In order to solve the above problems, researchers have done a lot of research and exploration, which can be summarized into two aspects: First, silicon is made into nanostructure or porous structure to alleviate the volume effect of silicon; second, it is introduced into silicon. The high conductive carbon material or the introduction of the second metal phase can not only effectively buffer the stress generated by the silicon during volume change, but also increase the electrical conductivity of the electrode material.

(一）纳米化 (a) Nanocrystallization

硅的纳米化主要包括：零维纳米化，即制备纳米硅颗粒 [3]。减小硅寸可以减小硅的绝对体积变化；一维纳米化，即制备硅纳米线或硅纳米管 [4-5]。硅纳米线及硅纳米管可以有效减小硅在充放电过程中的径向体积变化，并且在轴向上提供锂离子快速传导的通道；二维纳米化，即制备硅基薄膜 [6]。硅基薄膜可减小垂直方向上的体积变化。硅的纳米化能有效地减小硅的体积变化，改善硅的电化学性能，但生长纳米硅的成本较高。 The nanocrystallization of silicon mainly includes: Zero-dimensional nanocrystallization, that is, preparation of nano-silicon particles [3]. Reduce silicon Inch can reduce the absolute volume change of silicon; one-dimensional nanocrystallization, that is, the preparation of silicon nanowires or silicon nanotubes [4-5]. Silicon nanowires and silicon nanotubes can effectively reduce the radial volume change of silicon during charge and discharge, and provide a channel for rapid conduction of lithium ions in the axial direction; two-dimensional nanocrystallization, that is, the preparation of silicon-based films [6]. The silicon-based film can reduce the volume change in the vertical direction. The nanocrystallization of silicon can effectively reduce the volume change of silicon and improve the electrochemical performance of silicon, but the cost of growing nano-silicon is higher.

(二）多孔化 (ii) Porosity

硅的多孔化是指在硅颗粒内部形成孔道结构，这种孔道结构可以是微孔、介孔、大孔、空心或者是多种孔道结构的复合 [7-9]。孔道结构可以缓解硅在电化学反应中的体积效应，减小锂离子和电子的传输路径，并且有利于电解液的渗透。 The porosity of silicon refers to the formation of a pore structure inside the silicon particles, which may be microporous, mesoporous, macroporous, hollow or a composite of a plurality of pore structures [7-9]. The pore structure can alleviate the volume effect of silicon in the electrochemical reaction, reduce the transport path of lithium ions and electrons, and facilitate the permeation of the electrolyte.

(三）硅 /碳复合材料 (iii) Silicon/carbon composites

目前解决硅电极循环稳定性问题主要的方法是制备硅 /碳复合材料，即将硅与碳材料复合，以碳抑制或容纳硅的体积膨胀，使复合物同时具有硅的高比容量特性和碳材料良好的循环稳定性。根据材料的微观结构，硅 /碳复合材料可分为包覆型、嵌入型和分散型三类。 At present, the main method for solving the cycle stability problem of silicon electrodes is to prepare silicon/carbon composite materials, that is, silicon and carbon materials are compounded, and carbon is used to suppress or accommodate the volume expansion of silicon, so that the composite has both high specific capacity characteristics of silicon and carbon materials. Good cycle stability. Depending on the microstructure of the material, the silicon/carbon composites can be classified into cladding, embedded and dispersion types.

(1) 包覆型 (1) Cover type

包覆型的硅 /碳复合材料以硅为主体，在硅的表面包覆一层碳，碳层可以缓解硅因体积变化产生的应力作用并提供电极内部良好的电接触。包覆型硅 /碳复合材料中的硅含量一般较高，因此复合材料具有较高的可逆比容量。目前对包覆型硅 /碳复合材料研究的重点在于保证材料高比容量的同时提高材料的循环稳定性。 The coated silicon/carbon composite is mainly composed of silicon, and a layer of carbon is coated on the surface of the silicon. The carbon layer can relieve the stress caused by the volume change of the silicon and provide good electrical contact inside the electrode. The silicon content of the coated silicon/carbon composite is generally higher, so the composite has a higher reversible specific capacity. At present, the focus of research on coated silicon/carbon composites is to ensure the high specific capacity of the materials while improving the cycle stability of the materials.

Zhou 等 [10]通过水解正硅酸乙酯 (TE0S)在纳米硅表面合成了一层 Si 后高温热解蔗糖制得 Si@Si02/C复合物，再除去 Si02制得了核壳型的硅 /碳复合材料。该材料首次可逆比容量为 813. 9 mAh/g, 20 次循环后仍然具有 625. 3 mAh/g的容量。硅颗粒表面的无定形碳层提高了硅在嵌脱锂时的结构稳定性，改善了材料的导电性，从而使其电化学性能得到较大提高。 Zhou et al. [10] synthesized a layer of Si on the surface of nano-silicon by hydrolysis of tetraethyl orthosilicate (TE0S). The Si@Si02/C composite was prepared by post-high temperature pyrolysis of sucrose, and the core-shell type silicon/carbon composite material was obtained by removing SiO2. The material has a first reversible specific capacity of 813.9 mAh/g and still has a capacity of 655.3 mAh/g after 20 cycles. The amorphous carbon layer on the surface of the silicon particles improves the structural stability of the silicon during the intercalation and deintercalation, and improves the electrical conductivity of the material, thereby greatly improving the electrochemical performance.

Kim 等 [11]采用反相乳液法制备出纳米硅，直径为 5〜20 nm，经过碳包覆后的首次可逆比容量高达 3380 mAh/g, 40 次循环后仍可保持初始容量的 96%。 Kim et al. [11] prepared nano-silicones by inversion emulsion method with a diameter of 5~20 nm. The first reversible specific capacity after carbon coating was up to 3380 mAh/g, and 96% of the initial capacity was maintained after 40 cycles. .

Wang 等 [12]采用化学气相沉积法（CVD)在硅纳米线（SiNWs)表面沉积了石墨微片，然后高温处理 SiNW@G与石墨烯（RG0)的混合物制得了 SiNW@G@RG0复合材料。该材料首次可逆比容量为 1600 mAh/g, 循环 100次后容量保持率为 80%, 表现出优异的循环性能。 Wang et al [12] used chemical vapor deposition (CVD) to deposit graphite microchips on the surface of silicon nanowires (SiNWs), and then processed SiNW@G@RG0 composites by high temperature treatment of a mixture of SiNW@G and graphene (RG0). . The material has a first reversible specific capacity of 1600 mAh/g and a capacity retention of 80% after 100 cycles, showing excellent cycle performance.

Zhu等 [13]采用化学刻蚀的方法制备了 SiNWs, 并对 SiNWs进行氨化改性，然后通过静电吸附的方法制备了具有核壳结构的石墨烯 @SiNWs复合材料，它的首次可逆比容量约为 1648 mAh/g，首次库仑效率高达 80%, 循环 80次后仍然具有 1335 mAh/g的容量。 Zhu et al [13] prepared SiNWs by chemical etching, and modified the SiNWs by ammoniation. Then, the graphene@SiNWs composite with core-shell structure was prepared by electrostatic adsorption. Its first reversible specific capacity At approximately 1648 mAh/g, the first Coulomb efficiency is as high as 80%, and still has a capacity of 1335 mAh/g after 80 cycles.

Kim等 [14]通过萘钠还原 SiC14，再以 Si02球为模板制得了具有三维孔结构的硅 /碳复合材料。该材料表现出优异的循环性能和倍率性能， 0. 2C倍率的可逆比容量为 2820 mAh/g, 100次循环后的容量保持率为 99%, 即使在 3C倍率下，仍能放出 2158 mAh/g的可逆比容量。 Kim et al [14] reduced SiC14 by naphthalene sodium, and then prepared a silicon/carbon composite with three-dimensional pore structure using Si02 sphere as template. The material exhibits excellent cycle performance and rate performance. The reversible specific capacity of 0.2 C is 2820 mAh/g, and the capacity retention after 100 cycles is 99%. Even at 3C, 2158 mAh can be released. The reversible specific capacity of g.

(2) 嵌入型 (2) Embedded type

嵌入型硅 /碳复合材料是指将硅颗粒嵌入到碳基体中形成复合材料，其中碳基体包括无定形碳、石墨、石墨烯等。嵌入型硅 /碳复合材料中硅含量一般较低，因此其比容量也较低，但是其循环稳定性一般较好。目前对嵌入型硅 /碳料研究的重点是对碳基体的微观结构的优化以及复合材料中硅含量的提高，在保证电极材料优异循环稳定性的同时提高电极材料的比容量。 The embedded silicon/carbon composite material refers to embedding silicon particles into a carbon matrix to form a composite material, wherein the carbon matrix includes amorphous carbon, graphite, graphene, and the like. The silicon content of the embedded silicon/carbon composite is generally low, so its specific capacity is also low, but its cycle stability is generally better. Currently for embedded silicon/carbon The research focus is on the optimization of the microstructure of the carbon matrix and the improvement of the silicon content in the composite material, and the specific capacity of the electrode material is improved while ensuring excellent cycle stability of the electrode material.

Magasinski等 [ 15]将炭黑进行热处理得到导电骨架，然后利用两歩 CVD制备了具有树枝状敞开式碳骨架的硅 /碳复合材料。该材料表现出优异的电化学性能，首次循环以 0. 05C的电流进行活化，表现出〜 2000mAh/g 的放电容量，在 1C 倍率下充放电循环 100 次后容量无衰减。其优异的循环稳定性主要是因为材料中开放的多孔结构为硅的体积膨胀提供空间，并为锂离子的快速传输提供了通道。 Magasinski et al. [15] heat-treated carbon black to obtain a conductive skeleton, and then prepared a silicon/carbon composite material having a dendritic open carbon skeleton by two-turn CVD. The material exhibited excellent electrochemical performance, and the first cycle was activated with a current of 0.05 C, showing a discharge capacity of ~2000 mAh/g, and the capacity was not attenuated after 100 cycles of charge and discharge at 1 C rate. Its excellent cycle stability is mainly due to the fact that the open porous structure in the material provides space for the volume expansion of silicon and provides a channel for the rapid transfer of lithium ions.

Wang等 [ 16]以煤焦油为碳源，采用高温热处理法制备了嵌入型硅 /碳复合材料，其首次可逆比容量为 400. 3 mAh/g , 1000 次循环后仍可保持初始容量的 71. 3%, 表现出优异的循环性能。 Wang et al [16] used coal tar as carbon source to prepare embedded silicon/carbon composites by high temperature heat treatment. The first reversible specific capacity was 400. 3 mAh/g, and the initial capacity was maintained after 1000 cycles. 3%, showing excellent cycle performance.

Zhou等 [ 17]利用冷冻干燥和热还原的方法将硅颗粒***到石墨烯基体中，制备得到硅 /石墨烯复合材料。由于石墨烯具有优异的柔韧性，因此它能够有效地缓解硅在脱嵌锂过程中的剧烈体积变化，保持复合材料的结构稳定性和良好的电接触。该复合材料在 100次循环后保持 1153 mAh/g的容量，并且在 4 A/g电流密度下具有 803 mAh/g 的可逆比容量。 Zhou et al [17] used silicon freeze-dried and thermal reduction methods to insert silicon particles into a graphene-based body to prepare a silicon/graphene composite. Because graphene has excellent flexibility, it can effectively alleviate the dramatic volume change of silicon during deintercalation of lithium, maintaining the structural stability and good electrical contact of the composite. The composite maintained a capacity of 1153 mAh/g after 100 cycles and a reversible specific capacity of 803 mAh/g at a current density of 4 A/g.

(3) 分散型 (3) Decentralized type

分散型硅 /碳复合材料是指硅、碳材料在复合材料中以分子形式接触，硅高度分散在碳层中的复合材料。分散型硅 /碳复合材料能够最大限度地抑制硅的体积膨胀，从而维持电极良好的结构稳定性和容量。 Dispersed silicon/carbon composite refers to a composite material in which silicon and carbon materials are contacted in a molecular form in a composite material, and silicon is highly dispersed in a carbon layer. The dispersed silicon/carbon composite minimizes the bulk expansion of the silicon, thereby maintaining good structural stability and capacity of the electrode.

Yang [ 18]等以苯环连接石墨烯和纳米硅，这种结构能够防止纳米硅颗粒在充放电过程中因为体积效应从石墨烯表面脱落，保证电极材料的电活性，高电极材料的循环稳定性。该材料具有 1079 mAh/g的首次可逆比容量，循环 50 次后仍然具有 828 mAh/g的容量。 Yang [18] and other benzene rings are connected to graphene and nano-silicon. This structure can prevent nano-silicon particles from falling off from the surface of graphene due to volume effect during charge and discharge, ensuring the electrical activity of the electrode material. Cyclic stability of high electrode materials. The material has a first reversible specific capacity of 1079 mAh/g and still has a capacity of 828 mAh/g after 50 cycles.

(四）硅 /金属复合材料 (iv) Silicon/Metal Composites

除了碳材料，金属也具有优异的导电率和机械性能，能够有效地吸收硅因体积变化产生的应力，并保持电极良好的电接触，从而提高硅 /金属复合材料的电化学性能。有些金属不贡献嵌锂容量，仅作为结构稳定剂和导电剂存在，如 Fe、 Co、 Cu 等，我们称这类硅 /金属复合材料为硅 /惰性金属复合材料；有的金属，如 Sn、 Ag 等具有良好的电化学活性，不但能够稳定复合材料的结构，同时还能够为复合材料贡献储锂容量，我们称这类材料为硅 /活性金属复合材料。 In addition to carbon materials, metals also have excellent electrical and mechanical properties, which effectively absorb the stress generated by silicon due to volume changes and maintain good electrical contact of the electrodes, thereby improving the electrochemical properties of the silicon/metal composite. Some metals do not contribute to lithium intercalation capacity and exist only as structural stabilizers and conductive agents, such as Fe, Co, Cu, etc. We call these silicon/metal composites silicon/inert metal composites; some metals, such as Sn, Ag has good electrochemical activity, which not only stabilizes the structure of the composite, but also contributes to the lithium storage capacity of the composite. We call this material a silicon/active metal composite.

综上所述，针对硅负极材料在充放电过程中出现的体积膨胀导致电极的容量迅速衰减的问题，科研工作者已经做了较多的研究，并取得了一定的成果，但对于硅 /碳复合电极材料，目前的研究还缺乏对纳米硅与碳基体界面深入细致的研究和了解，不能做到在石墨疏水基面很好地稳定纳米硅，而在石墨疏水基面稳定纳米硅对于提高硅基负极材料的循环稳定性和寿命至关重要，且目前的研究所采用的方法歩骤较多，成本较高。因此，了解纳米硅颗粒与 NanoG 的相界面结构，开发成本较低、适合工业化生产的制备硅 /碳复合负极材料的新方法，将是今后硅负极材料研究的重点。 In summary, the volume expansion of the silicon anode material during charge and discharge causes the electrode capacity to rapidly decay. Researchers have done more research and achieved certain results, but for silicon/carbon Composite electrode materials, the current research also lacks in-depth research and understanding of the interface between nano-silicon and carbon matrix, can not achieve good stability of nano-silicon on the graphite hydrophobic surface, and stabilize nano-silicon on the graphite hydrophobic surface to improve silicon The cycle stability and life of the base anode material are critical, and the methods used in the current research are more frequent and costly. Therefore, understanding the phase-bound structure of nano-silicon particles and NanoG, and developing a new method for preparing silicon/carbon composite anode materials with low cost and suitable for industrial production will be the focus of future research on silicon anode materials.

发明内容 Summary of the invention

本发明的目的在于克服上述现有技术缺点，提供一种简单可行、成本较低、适合工业化生产的碳负载的纳米硅颗粒结构、制备方法及其应用。 The object of the present invention is to overcome the above-mentioned shortcomings of the prior art, and to provide a carbon-loaded nano-silicon particle structure, a preparation method and an application thereof which are simple and feasible, low in cost and suitable for industrial production.

为解决上述问题，本发明碳负载的纳米硅颗粒结构采取的技术方案为： 50% 以上的纳米硅颗粒负载在碳的 a-b基面，所述纳米硅颗粒中的介面部分同碳在介面通过化学反应形成硅 -碳化学键；纳米硅颗粒通过硅-碳化学键锚在碳的 a-b基面。 In order to solve the above problems, the carbon-supported nano-silicon particle structure of the present invention adopts a technical solution: 50% or more of the nano-silicon particles are supported on the ab-base of the carbon, and the interface portion of the nano-silicon particles The same carbon forms a silicon-carbon chemical bond through a chemical reaction at the interface; the nano silicon particles are anchored to the ab base of the carbon through a silicon-carbon chemical bond.

硅同碳的重量比例在 1 : 9到 3 : 1之间。 The weight ratio of silicon to carbon is between 1:9 and 3:1.

硅同碳的重量比例在 1 : 5到 2 : 1之间。 The weight ratio of silicon to carbon is between 1:5 and 2:1.

硅同碳的重量比例在 1 : 4到 1 : 1之间。 The weight ratio of silicon to carbon is between 1:4 and 1:1.

纳米硅颗粒的尺寸在 2nm到 lOOnm之间。 The size of the nano-silicon particles is between 2 nm and 100 nm.

纳米硅颗粒的尺寸在 5nm到 60nm之间。 The size of the nano-silicon particles is between 5 nm and 60 nm.

纳米硅颗粒的尺寸在 10nm到 30nm之间。 The size of the nano-silicon particles is between 10 nm and 30 nm.

所述碳是石墨、碳纳米管或导电碳黑。 The carbon is graphite, carbon nanotubes or conductive carbon black.

所述石墨是膨胀石墨或微纳米石墨；所述碳纳米管为多壁碳纳米管。 The graphite is expanded graphite or micro-nano graphite; the carbon nanotubes are multi-walled carbon nanotubes.

一种碳负载的纳米硅颗粒结构的制备方法，包括以下歩骤： A method for preparing a carbon-loaded nano-silicon particle structure, comprising the following steps:

a) 将纳米 Si0₂、镁粉和碳按比例混合，其中纳米 Si0₂同镁粉的重量比例 1. 24, 纳米 Si0₂同碳的重量比例在 2: 9到 6: 1之间; a) The nano-SiO _2, mixed in proportions of carbon and magnesium, wherein the weight ratio of magnesium powder with nano-SiO ₂ 1.24, with the weight ratio of the carbon nano-SiO ₂ in 2: 9-6: 1;

b) 将混合物 A在惰性气体气氛或真空下用球磨机球磨混合均匀，得混合物 B; c) 将混合物 B在惰性气体气氛下加热使镁粉和纳米 3:10₂发生化学反应，将纳米 Si0₂还原成硅； b) Mixing mixture A in a ball furnace under an inert gas atmosphere or under vacuum to obtain a mixture B; c) heating the mixture B under an inert gas atmosphere to chemically react the magnesium powder with nano 3:10 ₂ to form nano Si0 ₂ Reductive to silicon;

d) 酸洗去除反应副产物 MgO、未反应的镁和可溶性杂质； d) pickling to remove reaction by-product MgO, unreacted magnesium and soluble impurities;

e) 在惰性气体气氛或真空条件下加热使纳米硅颗粒与碳在介面进一歩发生反应，将纳米硅颗粒通过化学成键固定在碳的 a-b基面。 e) heating in an inert gas atmosphere or under vacuum to cause the nano-silicon particles to react with carbon in the interface, and the nano-silicon particles are fixed to the a-b base of the carbon by chemical bonding.

所述纳米 Si0₂为气相法白炭黑，包括表面改性后的白炭黑。 The nano-SiO ₂ is a fumed silica, including surface-modified silica.

所述纳米 8:10₂的直径在 lnm到 200nm之间。 The nanometer 8:10 _{2 has} a diameter between 1 nm and 200 nm.

所述纳米 8:10₂的直径在 5nm到 lOOnm之间。所述纳米 8：[0₂的直径在 5nm到 50nm之间。 The nanometer 8:10 _{2 has} a diameter between 5 nm and 100 nm. The nano 8: [0 _{2 has} a diameter between 5 nm and 50 nm.

所述歩骤 a) 中的混合包括机械混合或者先将 8:10₂负载到碳表面，然后再同镁粉混合。 The mixing in step a) involves mechanical mixing or first loading 8:10 ₂ onto the carbon surface and then mixing with the magnesium powder.

所述纳米 Si0₂同碳的重量比例在 2 : 5到 4: 1之间。 The weight ratio of the nano-SiO ₂ to carbon is between 2:5 and 4:1.

所述纳米 Si0₂同碳的重量比例在 1 : 2到 2 : 1之间。 The weight ratio of the nano-SiO ₂ to carbon is between 1:2 and 2:1.

本发明提供一种不对称超级电容，包括高比表面活性炭阳极、隔离阴极和阳极的隔膜、电解液以及阴极，所述阴极采用碳负载的纳米硅颗粒结构的材料制备。 The present invention provides an asymmetric supercapacitor comprising a high specific surface activated carbon anode, a separator for isolating the cathode and the anode, an electrolyte, and a cathode, the cathode being made of a carbon supported nano silicon particle structure material.

本发明提供一种锂离子电池，包括复合氧化物阳极、阴极、隔离阴极和阳极的隔膜以及电解液，所述阴极采用碳负载的纳米硅颗粒结构的材料制备。 The present invention provides a lithium ion battery comprising a composite oxide anode, a cathode, a separator for isolating the cathode and the anode, and an electrolyte prepared from a material of a carbon-loaded nano-silicon particle structure.

与现有技术相比，本发明具有以下有益效果：本发明制备的碳负载的纳米硅颗粒结构在碳的 a-b基面均匀分布着纳米硅颗粒，通过化学成键增强纳米硅同碳的 a-b基面的相互作用，制备性能稳定的电极材料。 Compared with the prior art, the present invention has the following beneficial effects: The carbon-supported nano-silicon particle structure prepared by the invention uniformly distributes the nano-silicon particles on the ab-base surface of the carbon, and strengthens the ab-base of the nano-silicon and carbon by chemical bonding. The surface interaction creates a stable electrode material.

本发明采用价格低廉的纳米 3:10₂为硅源，利用镁热反应在碳表面一歩固相合成纳米硅颗粒；在碳的 a-b基面制备分布均匀的纳米硅颗粒，通过形成化学键的途径，增强硅颗粒同碳的 a-b基面的相互作用，让纳米硅能较牢固地被固定在同碳的 a-b基面，制备比容量高、稳定性好的硅基负极材料，本发明简单可行、成本较低、适合工业化生产的制备硅 /碳负极材料的新方法，具有重要的研究意义和实用价值。 The invention adopts low-cost nano 3:10 ₂ as a silicon source, and utilizes a magnesium thermal reaction to synthesize nano silicon particles in a solid phase on a carbon surface; and prepares uniformly distributed nano silicon particles on ab base surface of carbon, by forming a chemical bond, The interaction between the silicon particles and the ab base surface of the carbon is enhanced, so that the nano silicon can be firmly fixed on the ab base surface of the same carbon to prepare a silicon-based anode material with high specific capacity and good stability, and the invention is simple and feasible, and the cost is low. The new method for preparing silicon/carbon anode materials suitable for industrial production has important research significance and practical value.

使用本发明碳负载的纳米硅颗粒结构制备的阴极能够应用到不对称超级电容及锂离子电池的阴极，能显著提升硅基复合材料的性能，经测试首次可逆比容量大于 2000 mAh/g , 200次循环后的容量保持率为 80%以上。附图说明 The cathode prepared by using the carbon-supported nano-silicon particle structure of the invention can be applied to the asymmetric supercapacitor and the cathode of the lithium ion battery, and can significantly improve the performance of the silicon-based composite material, and the first reversible specific capacity is tested to be greater than 2000 mAh/g, 200. The capacity retention after the second cycle was 80% or more. DRAWINGS

图 1为本发明当碳为多壁碳纳米管时的结构示意图； 1 is a schematic view showing the structure of carbon when the carbon is a multi-walled carbon nanotube;

图 2为本发明当碳为石墨时的结构示意图， 2 is a schematic structural view of the present invention when carbon is graphite;

其中，图 2 ( a) 为其截面示意图，图 2 (b ) 为其鸟瞰图； Figure 2 (a) is a schematic cross-sectional view, and Figure 2 (b) is a bird's eye view;

图 3为本发明的纳米石墨微片的制备过程图； 3 is a diagram showing a preparation process of the nanographite microchip of the present invention;

图 4为本发明的纳米硅 /NanoG复合材料的制备过程图； 4 is a diagram showing the preparation process of the nano-silicon/NanoG composite material of the present invention;

图 5为本发明的 NanoG的 SEM照片； Figure 5 is a SEM photograph of the NanoG of the present invention;

图 6为本发明的纳米硅 /NanoG复合材料的 SEM照片； Figure 6 is a SEM photograph of the nano-silicon/NanoG composite material of the present invention;

图 Ί为本发明的纳米硅 /NanoG复合材料的 EDS分析图； Figure Ί is an EDS analysis diagram of the nano-silicon/NanoG composite material of the present invention;

图 8为本发明的纳米硅 /NanoG复合材料的拉曼光谱图； 8 is a Raman spectrum diagram of the nano-silicon/NanoG composite material of the present invention;

图 9为本发明的纳米硅 /NanoG复合材料的 TEM图； Figure 9 is a TEM image of the nano-silicon/NanoG composite material of the present invention;

图 10 为本发明的纳米硅 /NanoG负极复合材料的 XRD图； 10 is an XRD diagram of a nano-silicon/NanoG anode composite material of the present invention;

图 U为本发明的制备过程图； Figure U is a diagram of the preparation process of the present invention;

其中， 1、纳米硅颗粒 2、多壁碳纳米管 3、硅-碳界面 4、石墨。 Among them, 1, nano silicon particles 2, multi-walled carbon nanotubes 3, silicon-carbon interface 4, graphite.

具体实施方式 detailed description

以下结合附图以及实施例对本发明做进一歩详细说明： The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

参见图 1，本发明的碳负载的纳米硅颗粒结构包括 50%以上的纳米硅颗粒 1 负载在多壁碳纳米管 2的 a-b基面，形成硅-碳界面 3，，纳米硅颗粒中的部分硅原子同多壁碳纳米管 2在介面通过化学反应形成硅 -碳化学键；纳米硅颗粒 1通过硅-碳化学键锚在多壁碳纳米管 2的 a-b基面。 Referring to FIG. 1, the carbon-supported nano-silicon particle structure of the present invention comprises more than 50% of the nano-silicon particles 1 supported on the ab-base of the multi-walled carbon nanotubes 2, forming a silicon-carbon interface 3, and a portion of the nano-silicon particles. The silicon atom forms a silicon-carbon chemical bond with the multi-walled carbon nanotube 2 through a chemical reaction at the interface; the nano-silicon particle 1 is anchored to the ab-base surface of the multi-walled carbon nanotube 2 by a silicon-carbon chemical bond.

其中，硅同多壁碳纳米管 2的重量比例优选在 1 : 9到 3 : 1之间，更优选在 1 : 5 到 2： 1之间，最优选在 1 : 4到 1： 1之间，纳米硅颗粒 1的尺寸优选在 2nm 之间，更优选在 5nm到 60nm之间，最优选在 10nm到 30nm之间。 Wherein the weight ratio of silicon to multi-walled carbon nanotubes 2 is preferably between 1:9 and 3:1, more preferably between 1:5 and 2:1, most preferably between 1:4 and 1:1. The size of the nano silicon particles 1 is preferably 2 nm. More preferably, it is between 5 nm and 60 nm, most preferably between 10 nm and 30 nm.

参见图 2，本发明的碳负载的纳米硅颗粒结构包括 50%以上的纳米硅颗粒 1 负载在石墨 4的 a-b基面，形成硅-碳界面 3，纳米硅颗粒中的部分硅原子同石墨 4在介面通过化学反应形成硅 -碳化学键；纳米硅颗粒 1通过硅 -碳化学键锚在石墨 4的 a-b基面，其中石墨为纳米石墨微片或膨胀石墨。 Referring to FIG. 2, the carbon-supported nano-silicon particle structure of the present invention comprises more than 50% of the nano-silicon particles 1 supported on the ab-base of the graphite 4 to form a silicon-carbon interface 3, and a part of the silicon atoms in the nano-silicon particles are the same as the graphite 4 A silicon-carbon chemical bond is formed at the interface by a chemical reaction; the nano silicon particle 1 is anchored to the ab base surface of the graphite 4 by a silicon-carbon chemical bond, wherein the graphite is a nanographite microchip or expanded graphite.

其中，硅同石墨 4的重量比例优选在 1:9到 3:1之间，更优选在 1:5到 2:1 之间，最优选在 1: 4到 1:1之间，纳米硅颗粒 1的尺寸优选在 2nm到 lOOnm之间，更优选在 5nm到 60nm之间，最优选在 10nm到 30nm之间。 Wherein the weight ratio of silicon to graphite 4 is preferably between 1:9 and 3:1, more preferably between 1:5 and 2:1, most preferably between 1:4 and 1:1, nano-silicon particles The size of 1 is preferably between 2 nm and 100 nm, more preferably between 5 nm and 60 nm, and most preferably between 10 nm and 30 nm.

本发明提供的一种碳负载的纳米硅颗粒结构的制备方法，包括以下歩骤： a) 将纳米 Si0₂、镁粉和碳混合，得混合物 A, 其混合方式为简单机械混合或用负载法先将纳米硅颗粒 1负载到碳 2表面，再同镁粉机械混合，其中纳米 Si0₂ 同镁粉的重量比例 24; 纳米 Si0₂同碳的重量比例在 2:9到 6: 1之间，优选为 2: 5到 4: 1之间，最优选在 1: 2到 2: 1之间得混合物 A; 其中纳米 Si0₂ 包括，但不限于气相法白炭黑（Aerosil Fumed Silica), 比如由美国公司 Cabot 生产的未经处理的 HP-60, M-5, H-5, HS-5, EH-5和表面处理后的 TS-530, 610， TS720; 由德国公司 EVONIK生产的表面亲水 Aerosil 200， Aerosil 255, Aerosil 300， Aerosil 380 和表面亲油 Aerosil R202, Aerosil R208, Aerosil R106, Aerosil R812; 纳米 Si02的直径在 lnm到 200nm之间，优选为 5nm到 lOOnm之间，最优选为 5nm到 50纳米之间。 The invention provides a method for preparing a carbon-loaded nano-silicon particle structure, comprising the following steps: a) mixing nano-SiO ₂ , magnesium powder and carbon to obtain a mixture A, which is mixed by simple mechanical mixing or by a load method. First, the nano silicon particle 1 is loaded onto the surface of the carbon 2, and then mechanically mixed with the magnesium powder, wherein the weight ratio of the nano SiO _{2 to} the magnesium powder is 24; the weight ratio of the nano SiO _{2 to} the carbon is between 2:9 and 6:1. Preferably, the mixture A is obtained between 2:5 and 4:1, most preferably between 1:2 and 2:1; wherein the nano-SiO ₂ comprises, but is not limited to, Aerosil Fumed Silica, such as Untreated HP-60, M-5, H-5, HS-5, EH-5 and surface treated TS-530, 610, TS720 produced by American company Cabot; surface hydrophilic produced by German company EVONIK Aerosil 200, Aerosil 255, Aerosil 300, Aerosil 380 and surface oleophilic Aerosil R202, Aerosil R208, Aerosil R106, Aerosil R812; nano SiO 2 having a diameter between 1 nm and 200 nm, preferably between 5 nm and 100 nm, most preferably 5 nm To 50 nanometers.

b) 将混合物 A在惰性气体气氛或真空下用球磨机球磨混合均匀，得混合物 B; c) 将混合物 B在惰性气氛下加热使镁和 3:10₂发生化学反应，将 Si0₂还原成硅；该还原反应先在 600° C反应两小时到六小时，然后在 650° C反应到四小时，最后 700 ° C反应半小时到两小时之间。 b) mixing mixture A in a ball furnace under an inert gas atmosphere or under vacuum to obtain a mixture B; c) heating the mixture B under an inert atmosphere to chemically react magnesium with 3:10 _{2 to} reduce SiO ₂ to silicon; The reduction reaction is first carried out at 600 ° C for two hours to six hours, followed by a reaction at 650 ° C. After four hours, the last 700 ° C reaction is between half an hour and two hours.

d) 酸洗去除反应副产物 Mg0、未反应的镁和可溶性杂质；酸洗用稀盐酸在室温下进行，盐酸的浓度在 1 : 6到 1 : 1之间； d) pickling removes reaction by-product Mg0, unreacted magnesium and soluble impurities; pickling is carried out at room temperature with dilute hydrochloric acid, and the concentration of hydrochloric acid is between 1:6 and 1:1;

e) 在惰性气体或真空条件下加热使纳米硅颗粒与碳在介面发生反应，将纳米硅颗粒通过化学成键固定在碳的 a-b基面，其中介面反应的温度在 700 ° C到 1200° C之间，优选在 800° C到 1000 ° C之间。 e) heating under inert gas or vacuum to react the nano-silicon particles with carbon at the interface, and fixing the nano-silicon particles to the ab-side of the carbon by chemical bonding, wherein the temperature of the interface reaction is between 700 ° C and 1200 ° C Preferably, it is between 800 ° C and 1000 ° C.

实施例 1 : Example 1

1、纳米石墨微片（NanoG) 的制备 1. Preparation of nanographite microchips (NanoG)

参见图 3，先采用强酸对天然鳞片石墨进行氧化插层，制备石墨插层化合物 (GIC) , 然后高温快速处理 GIC， GIC 中层间的酸根离子快速分解、膨胀，导致石墨层间距增大，形成膨胀石墨 (EG) , 将 EG浸入 1-甲基 -2-吡咯垸酮 (匪 P)中，超声处理一定时间，使 EG内的溶剂形成气泡并破碎，产生瞬间强烈的冲击波，形成高速射流，使得 EG 上的微片结构完全脱落，制备出游离的纳米石墨微片 ( NanoG )。 Referring to Fig. 3, the natural flake graphite is firstly oxidized and intercalated with a strong acid to prepare a graphite intercalation compound (GIC), and then the GIC is rapidly processed at a high temperature, and the acid ions between the layers in the GIC rapidly decompose and expand, resulting in an increase in the graphite layer spacing. Formed expanded graphite (EG), immersed in EG in 1-methyl-2-pyrrolidone (匪P), sonicated for a certain period of time, causing bubbles in the EG to form bubbles and break up, producing a momentary strong shock wave, forming a high-speed jet So that the microchip structure on the EG is completely detached, and a free nanographite microchip ( NanoG) is prepared.

(2) 参见图 4，纳米硅 /纳米石墨微片复合材料的制备 (2) See Figure 4, Preparation of nano-silicon/nano-graphite microchip composites

a)、将纳米石墨微片、纳米 Si0₂和镁粉按照如下比例机械混合：其中，纳米 Si0₂同镁粉的摩尔比例为 1. 24，纳米 Si0₂同碳的重量比例为 2 : 9，得混合物 A; 该纳米 Si0₂为气相法白炭黑，其直径为 lnm; a), the nano-graphite micro-sheet, the nano-SiO ₂ and the magnesium powder are mechanically mixed according to the following ratio: wherein, the molar ratio of the nano-SiO _{2 to} the magnesium powder is 1. 24, the weight ratio of the nano-Si _{2 2 to} the carbon is 2: 9, a mixture of A; the nano-SiO ₂ is a fumed silica, the diameter of which is 1 nm;

b )、将混合物 A加到充满氩气的玛瑙罐中，在球磨机上球磨使之混合均匀，得混合物 B; b), the mixture A is added to an argon-filled agate tank, ball milled on a ball mill to make it evenly mixed, to obtain a mixture B;

c )、然后将混合物 B置于管式炉中，在氩气保护下进行镁热反应，该还原反应先在 600 ° C反应两小时，然后在 650° C反应一小时，最后 700° C 小时； c), then placing the mixture B in a tube furnace and performing a magnesium thermal reaction under argon gas treatment, the reaction is first carried out at 600 ° C for two hours, then at 650 ° C for one hour, and finally at 700 ° C. hour;

d)反应后用稀盐酸在室温下去除反应副产物 Mg0、未反应的镁和可溶性杂质，盐酸的浓度为 1 : 1 ; d) After the reaction, the reaction by-product Mg0, unreacted magnesium and soluble impurities are removed with dilute hydrochloric acid at room temperature, and the concentration of hydrochloric acid is 1:1;

e) 在氩气或真空条件下加热使纳米硅颗粒与碳在介面发生反应，介面反应的温度为 700° C, 将纳米硅颗粒通过化学成键固定在碳的 a-b基面，得到碳负载的纳米硅颗粒。 e) heating under argon or vacuum to react the nano-silicon particles with carbon at the interface, the temperature of the interface reaction is 700 ° C, and the nano-silicon particles are fixed to the ab surface of the carbon by chemical bonding to obtain a carbon-loaded Nano silicon particles.

实施例 2: Example 2:

参见图 3，先采用强酸对天然鳞片石墨进行氧化插层，制备石墨插层化合物 (GIC)。然后高温快速处理 GIC， GIC 中层间的酸根离子快速分解、膨胀，导致石墨层间距增大，形成膨胀石墨 (EG)。将 EG浸入 1-甲基 -2-吡咯垸酮 (匪 P)中，超声处理一定时间，使 EG内的溶剂形成气泡并破碎，产生瞬间强烈的冲击波，形成高速射流，使得 EG 上的微片结构完全脱落，制备出游离的纳米石墨微片 ( NanoG )。 Referring to Figure 3, a graphite intercalation compound (GIC) is prepared by oxidizing intercalation of natural flake graphite with a strong acid. Then, the GIC is rapidly processed at a high temperature, and the acid ions between the layers in the GIC rapidly decompose and expand, resulting in an increase in the spacing of the graphite layers to form expanded graphite (EG). The EG is immersed in 1-methyl-2-pyrrolidone (匪P), sonicated for a certain period of time, so that the solvent in the EG forms bubbles and breaks, generating an instantaneous strong shock wave, forming a high-speed jet, so that the micro-chip on the EG The structure was completely detached, and a free nanographite microchip ( NanoG) was prepared.

a)、将纳米石墨微片、纳米 SiO^n镁粉按照如下比例先将纳米 Si0₂负载到碳表面，然后再同镁粉混合：其中，纳米 Si0₂同镁粉的摩尔比例为 4，纳米 Si0₂ 同碳的重量比例为 6 : 1，得混合物 A;该纳米 3:10₂为气相法白炭黑，其直径为 5nm; b )、将混合物 A加到充满氩气的玛瑙罐中，在球磨机上球磨使之混合均匀，得混合物 B; A), the graphite nanosheets, magnesium nano SiO ^ n in the following proportions to a first load of carbon nano Si0 ₂ surface, and then mixed with magnesium: wherein the molar ratio of magnesium powder with nano Si0 ₂ to 4, nano The weight ratio of SiO ₂ to carbon is 6 : 1, to obtain a mixture A; the nano 3:10 ₂ is a fumed silica having a diameter of 5 nm; b), the mixture A is added to an agate tank filled with argon gas, Ball milling on a ball mill to mix it evenly, to obtain a mixture B;

c )、然后将混合物 B置于管式炉中，在氩气保护下进行镁热反应，该还原反应先在 600 ° C反应三小时，然后在 650° C反应二小时，最后 700° C 小时； c), then placing the mixture B in a tube furnace and carrying out a magnesium thermal reaction under argon gas treatment, the reduction reaction is first carried out at 600 ° C for three hours, then at 650 ° C for two hours, and finally at 700 ° C. hour;

d)反应后用稀盐酸在室温下去除反应副产物 Mg0、未反应的镁和可溶性杂质，盐酸的浓度为 1 : 2， d) After the reaction, the reaction by-product Mg0, unreacted magnesium and soluble impurities are removed with dilute hydrochloric acid at room temperature, and the concentration of hydrochloric acid is 1:2.

e) 在氩气或真空条件下加热使纳米硅颗粒与碳在介面发生反应，介面反应的温度为 800° C, 将纳米硅颗粒通过化学成键固定在碳的 a-b基面，得到碳负载的纳米硅颗粒。 e) heating under argon or vacuum to react the nano-silicon particles with carbon at the interface, the temperature of the interface reaction is 800 ° C, and the nano-silicon particles are fixed to the ab-base of the carbon by chemical bonding to obtain a carbon-loaded Nano silicon particles.

实施例 3: Example 3:

a)、将纳米石墨微片、纳米 Si0₂和镁粉按照如下比例混合：其中，纳米 Si02 Si0₂同镁粉的摩尔比例为 6，纳米 Si0₂同碳的重量比例为 2 : 5，得混合物 A; 该纳米 Si0₂为气相法白炭黑，其直径为 50nm_; a), the nanographite microchip, nano SiO ₂ and magnesium powder are mixed according to the following ratio: wherein the molar ratio of nano SiO ₂ SiO ₂ to magnesium powder is 6, and the weight ratio of nano SiO ₂ to carbon is 2: 5, to obtain a mixture A; the nano-SiO ₂ is a fumed silica having a diameter of 50 nm _;

c )、然后将混合物 B置于管式炉中，在氩气保护下进行镁热反应，该还原反应先在 600 ° C反应四小时，然后在 650° C反应三小时，最后 700° C 个半小时。 c), then placing the mixture B in a tube furnace and performing a magnesium thermal reaction under argon gas treatment, which is first reacted at 600 ° C for four hours, then at 650 ° C for three hours, and finally at 700 ° C. One and a half hours.

d)反应后用稀盐酸在室温下去除反应副产物 Mg0、未反应的镁和可溶性杂质，盐酸的浓度为 1 : 4; d) after the reaction with dilute hydrochloric acid at room temperature to remove the reaction by-product Mg0, unreacted magnesium and soluble impurities, the concentration of hydrochloric acid is 1: 4;

e) 在氩气或真空条件下加热使纳米硅颗粒与碳在介面发生反应，介面反应的温度为 1000° C, 将纳米硅颗粒通过化学成键固定在碳的 a-b基面，得到碳负载的纳米硅颗粒。 e) heating under argon or vacuum to react the nano-silicon particles with carbon at the interface, the temperature of the interface reaction is 1000 ° C, and the nano-silicon particles are fixed to the ab base of the carbon by chemical bonding to obtain a carbon-loaded Nano silicon particles.

实施例 4: Example 4:

a)、将纳米石墨微片、纳米 Si0₂和镁粉按照如下比例混合：其中，纳米 Si0₂ 同镁粉的摩尔比例为 4，纳米 Si0₂同碳的重量比例为 2 : 1，得混合物 A; 该纳米 Si0₂为气相法白炭黑，其直径为 60nm_; a), the nanographite microchip, the nano-SiO ₂ and the magnesium powder are mixed in the following proportions: wherein the molar ratio of the nano-SiO _{2 to} the magnesium powder is 4, and the weight ratio of the nano-SiO _{2 to} the carbon is 2: 1, and the mixture A is obtained. The nano-SiO ₂ is a fumed silica having a diameter of 60 nm _;

c )、然后将混合物 B置于管式炉中，在氩气保护下进行镁热反应，该还原反应先在 600 ° C反应四小时，然后在 650° C反应二小时，最后 700° C 个半小时； c), then placing the mixture B in a tube furnace and carrying out a magnesium thermal reaction under argon gas treatment, the reduction reaction is first carried out at 600 ° C for four hours, then at 650 ° C for two hours, and finally at 700 ° C. One and a half hours;

d)反应后用稀盐酸在室温下去除反应副产物 Mg0、未反应的镁和可溶性杂质，盐酸的浓度为 1 : 6; d) after the reaction with dilute hydrochloric acid at room temperature to remove the reaction by-product Mg0, unreacted magnesium and soluble impurities, the concentration of hydrochloric acid is 1: 6;

e) 在氩气或真空条件下加热使纳米硅颗粒与碳在介面发生反应，介面反应的温度为 1200° C, 将纳米硅颗粒通过化学成键固定在碳的 a-b基面，得到碳负载的纳米硅颗粒。 e) heating under argon or vacuum to react the nano-silicon particles with carbon at the interface, the temperature of the interface reaction is 1200 ° C, and the nano-silicon particles are fixed to the ab-base of carbon through chemical bonding to obtain carbon-loaded Nano silicon particles.

实施例 5: Example 5

a)、将膨胀石墨、纳米 Si0₂和镁粉按照如下比例混合：其中，纳米 3:10₂同镁粉的摩尔比例为 2. 5，纳米 Si0₂同碳的重量比例为 1 : 2，得混合物 A; 该纳米 Si0₂为气相法白炭黑，其直径为 5nm; a, the weight ratio of nano-Si0 ₂ to carbon is 1: 2, obtained by mixing the expanded graphite, the nano-SiO ₂ and the magnesium powder in the following ratio: wherein, the molar ratio of the nano-sized 3:10 _{2 to} the magnesium powder is 2.5; Mixture A; the nano-SiO ₂ is a fumed silica having a diameter of 5 nm;

c )、然后将混合物 B置于管式炉中，在氩气保护下进行镁热反应，该还原反应先在 600 ° C反应四小时，然后在 650° C反应二小时，最后 700° C反应一个半小时； c), then placing the mixture B in a tube furnace, and performing a magnesium thermal reaction under argon gas treatment, the reduction reaction is first carried out at 600 ° C for four hours, then at 650 ° C for two hours, and finally at 700 ° C reaction. One and a half hours;

d)反应后用稀盐酸在室温下去除反应副产物 Mg0、未反应的镁和可溶性杂质，盐酸的浓度为 1 : 3; d) after the reaction with dilute hydrochloric acid at room temperature to remove the reaction by-product Mg0, unreacted magnesium and soluble impurities, the concentration of hydrochloric acid is 1: 3;

实施例 6: Example 6:

a)、将多壁碳纳米管、纳米 Si0₂和镁粉按照如下比例混合：其中，纳：同镁粉的摩尔比例为 3. 5，纳米 Si0₂同碳的重量比例为 2 : 5，得混合物 A; 该纳米 Si0₂为气相法白炭黑，其直径为 lOnm; a) mixing multi-walled carbon nanotubes, nano-SiO ₂ and magnesium powder in the following proportions: wherein: The molar ratio of the nano-Si0 _{2 to} the carbon is 2: 5, to obtain a mixture A; the nano-SiO ₂ is a fumed silica, the diameter of which is lOnm;

c )、然后将混合物 B置于管式炉中，在氩气保护下进行镁热反应，该还原反应先在 600 ° C反应四小时，然后在 650 ° C反应二小时，最后 700 ° C反应一个半小时； c), then placing the mixture B in a tube furnace and carrying out a magnesium thermal reaction under argon gas treatment, the reduction reaction is first carried out at 600 ° C for four hours, then at 650 ° C for two hours, and finally at 700 ° C reaction. One and a half hours;

e) 在氩气或真空条件下加热使纳米硅颗粒与碳在介面发生反应，介面反应的温度为 1200 ° C , 将纳米硅颗粒通过化学成键固定在碳的 a-b基面，得到碳负载的纳米硅颗粒。 e) heating under argon or vacuum to react the nano-silicon particles with carbon at the interface, the temperature of the interface reaction is 1200 ° C, and the nano-silicon particles are fixed to the ab-base of carbon through chemical bonding to obtain carbon-loaded Nano silicon particles.

纳米硅与 NanoG的相界面结构及两者表面的相互作用的研究 Study on the interfacial structure of nano-silicon and NanoG and the interaction between the two surfaces

使用球差校正高分辨透射电镜在原子尺度研究纳米硅颗粒与 NanoG的相界面结构，探讨两者表面相互作用的机理，并***研究硅颗粒尺寸、硅的含量和充放电对这种相互作用的影响规律，探索使硅颗粒稳定在 NanoG疏水基面的方法。在了解硅颗粒同 NanoG表面相互作用的机理的基础上，优化反应条件，在石墨疏水基面制备分布均匀的纳米硅颗粒，通过高温处理形成化学键，增强纳米硅同 NanoG表面的相互作用，采用 SEM、 TEM、 EDS、 XRD、 Raman研究硅颗粒尺寸、硅的含量等对纳米硅在 NanoG表面的分布和纳米硅与 NanoG表面成键的影响规律，制备纳米硅 /NanoG复合材料。 The interfacial structure of nano-silicon particles and NanoG was studied at the atomic scale using spherical aberration-corrected high-resolution transmission electron microscopy. The mechanism of surface interaction between the two was investigated. The silicon particle size, silicon content and charge-discharge interaction were systematically studied. Influencing the law, explore the method of stabilizing silicon particles on the hydrophobic surface of NanoG. On the basis of understanding the mechanism of the interaction between silicon particles and NanoG surface, the reaction conditions were optimized, and the uniformly distributed nano-silicon particles were prepared on the graphite hydrophobic surface. The chemical bonds were formed by high temperature treatment to enhance the interaction between nano-silicon and NanoG surface. TEM, EDS, XRD, Raman study the silicon particle size, silicon content, etc. on the distribution of nano-silicon on the surface of NanoG and the influence of nano-silicon on the surface of NanoG, to prepare nano-silicon/NanoG composites.

参见图 5为 NanoG的 SEM图，从图中我们可以看出 NanoG直径大约为 1 厚度大约在 10nm。参见图 6为纳米硅 /NanoG复合材料的 SEM照片及 EDS分析，从图 6 ( a) ，图 6 ( b ) 及 6 ( c ) 中我们能够看出大量的小颗粒均匀分散在 NanoG疏水基面。 See Figure 5 for the SEM image of the NanoG. From the figure we can see that the NanoG has a diameter of about 1. The thickness is approximately 10 nm. See Figure 6 for SEM and EDS analysis of nano-silicon/NanoG composites. From Figure 6 (a), Figure 6 (b) and 6 (c), we can see that a large number of small particles are uniformly dispersed on the NanoG hydrophobic surface. .

参见图 7为本发明的纳米硅 /NanoG复合材料的 EDS分析图，从 EDS分析表明，纳米硅 /NanoG复合材料主要含有碳、硅两种元素，硅的含量为 10. lwt%， EDS分析的具体结果详见表 1。 The EDS analysis of the nano-silicon/NanoG composite material is characterized by the EDS analysis. The nano-silicon/NanoG composite material mainly contains carbon and silicon. The content of silicon is 10. lwt%, EDS analysis The specific results are shown in Table 1.

表 1为 EDS分析结果 Table 1 shows the results of EDS analysis.

参见图 8为本发明的纳米硅 /NanoG复合材料的拉曼光谱图；其中图 8 ( a) 为对该材料进行区域扫描所得的拉曼光谱图，其中三个明显的特征峰，在 1571. 8 cm-1处、 1354. 4 cm-1处分别代表石墨的 G峰和 D峰，在 514. 2 cm-1处代表硅的散射峰，另外在 958. 4 cm-1处出现一个较弱的散射峰，有可能是纳米硅与 NanoG两者相互作用产生的散射峰。图 8 ( b ) 是该材料硅含量高的点的拉曼光谱图，该点用红色表示，图 8 ( c ) 是该材料硅含量低的点的拉曼光谱图，该点用黑色表示，图 8 ( b )、 8 ( c ) 表明大量的硅颗粒均匀分散在 NanoG疏水基面。 8 is a Raman spectrum of the nano-silicon/NanoG composite of the present invention; wherein FIG. 8( a ) is a Raman spectrum obtained by performing regional scanning on the material, wherein three distinct characteristic peaks are at 1571. 8 cm-1, 1354. 4 cm-1 represent the G and D peaks of graphite, respectively, representing the scattering peak of silicon at 514.2 cm-1, and a weaker at 958. 4 cm-1. The scattering peak may be a scattering peak generated by the interaction between nano-silicon and NanoG. Figure 8 (b) is a Raman spectrum of the point where the silicon content of the material is high, which is shown in red, and Figure 8 (c) is a Raman spectrum of the point where the silicon content of the material is low, which is indicated by black. Figures 8(b) and 8(c) show that a large amount of silicon particles are uniformly dispersed on the hydrophobic surface of NanoG.

参见图 9为纳米硅 /NanoG复合材料的 TEM图，图中显示纳米硅较均匀分散在 NanoG上，这和 SEM观察到的结果是一致的。 See Figure 9 for a TEM image of a nano-silicon/NanoG composite. The figure shows that nano-silicon is more uniformly dispersed on the NanoG, which is consistent with the results observed by SEM.

参见图 10为纳米硅 /NanoG负极复合材料的 XRD图。从图中可以清晰地看到碳及硅的一系列衍射峰，进一歩证明镁热反应合成了纳米硅颗粒，另外在 2 Θ =35. 6°处出现了一个小的衍射峰，有可能是纳米硅与 NanoG两者相互作的衍射峰。以上研究结果表明，我们采用镁热反应在 NanoG疏水基面合成了均匀分散的纳米硅颗粒，且纳米硅与 NanoG两者表面存在相互作用，证明了本项目的可行性。在后面的工作中，我们将在原子尺度对纳米硅与 NanoG 的相界面结构进行研究，了解两者表面相互作用的机理，证明高温热处理使纳米硅与 NanoG界面形成化学键，增强纳米硅同 NanoG表面的相互作用，制备高性能纳米硅 /NanoG复合负极材料。 See Figure 10 for an XRD pattern of a nano-silicon/NanoG anode composite. A series of diffraction peaks of carbon and silicon can be clearly seen from the figure. Further, a magnesia reaction is synthesized to synthesize nano-silicon particles, and a small diffraction peak appears at 2 Θ =35. 6°, which may be Nano silicon and NanoG interact with each other The diffraction peak. The above results show that we have synthesized the uniformly dispersed nano-silicon particles on the hydrophobic surface of NanoG by magnesium thermal reaction, and the interaction between nano-silicon and NanoG surface proves the feasibility of the project. In the following work, we will study the phase interface structure between nano-silicon and NanoG at the atomic scale to understand the mechanism of surface interaction between the two, and prove that the high temperature heat treatment forms a chemical bond between the nano-silicon and NanoG interface, and enhances the surface of nano-silicon and NanoG. The interaction of the high-performance nano-silicon/NanoG composite anode material.

Claims

权利要求书 Claim

1. 一种碳负载的纳米硅颗粒结构，其特征在于， 50%以上的纳米硅颗粒负载在碳的 a-b基面，所述纳米硅颗粒中的介面部分硅原子同碳在介面通过化学反应形成硅 -碳化学键；纳米硅颗粒通过硅 -碳化学键锚在碳的 a-b基面。 A carbon-loaded nano-silicon particle structure, characterized in that more than 50% of the nano-silicon particles are supported on the ab-base of the carbon, and the silicon atoms in the interface of the nano-silicon particles are formed by chemical reaction with the carbon at the interface. Silicon-carbon chemical bonds; nano-silicon particles are anchored to the ab-base of carbon via a silicon-carbon chemical bond.

2. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，硅同碳的重量比例在 1 : 9到 3 : 1之间。 2. The carbon-loaded nano-silicon particle structure according to claim 1, wherein the weight ratio of silicon to carbon is between 1:9 and 3:1.

3. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，硅同碳的重量比例在 1 : 5到 2 : 1之间。 3. The carbon-loaded nano-silicon particle structure according to claim 1, wherein the weight ratio of silicon to carbon is between 1:5 and 2:1.

4. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，硅同碳的重量比例在 1 : 4到 1 : 1之间。 4. The carbon-loaded nano-silicon particle structure according to claim 1, wherein the weight ratio of silicon to carbon is between 1:4 and 1:1.

5. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，纳米硅颗粒的尺寸在 2nm到 lOOnm之间。 The carbon-supported nano-silicon particle structure according to claim 1, wherein the nano-silicon particles have a size of between 2 nm and 100 nm.

6. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，纳米硅颗粒的尺寸在 5nm到 60nm之间。 The carbon-loaded nano-silicon particle structure according to claim 1, wherein the nano-silicon particles have a size of between 5 nm and 60 nm.

7. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，纳米硅颗粒的尺寸在 10nm到 30nm之间。 The carbon-supported nano-silicon particle structure according to claim 1, wherein the nano-silicon particles have a size of between 10 nm and 30 nm.

8. 根据权利要求 1 所述的碳负载的纳米硅颗粒结构，其特征在于，所述碳是石墨、碳纳米管或导电碳黑。 The carbon-supported nano-silicon particle structure according to claim 1, wherein the carbon is graphite, carbon nanotubes or conductive carbon black.

9. 根据权利要求 8所述的碳负载的纳米硅颗粒结构，其特征在于，所述石墨是膨胀石墨或纳米石墨微片；所述碳纳米管为多壁碳纳米管。 9. The carbon-loaded nano-silicon particle structure according to claim 8, wherein the graphite is expanded graphite or nano-graphite microchip; and the carbon nanotube is multi-walled carbon nanotube.

10.—种碳负载的纳米硅颗粒结构的制备方法，其特征在于，包括以下歩骤: a) 将纳米 Si0₂、镁粉和碳按比例混合，得到混合物 A, 其中，纳米 3:10₂同镁粉的重量比例 1. 24，纳米 Si0₂同碳的重量比例在 2: 9到 6: 1之间： b) 将混合物 A在惰性气体气氛或真空下用球磨机球磨混合均匀，得混合物 B c) 将混合物 B在惰性气体气氛下加热使镁粉和纳米 3:10₂发生化学反应， 4 纳米 Si0₂还原成硅； 10. A method for preparing a carbon-loaded nano-silicon particle structure, comprising the steps of: a) mixing nano-SiO ₂ , magnesium powder and carbon in proportion to obtain a mixture A, wherein, nano 3:10 ₂ The weight ratio of the same to the magnesium powder is 1.24, and the weight ratio of the nano-Si0 _{2 to} the carbon is between 2:9 and 6:1: b) Mixing mixture A in a ball furnace under an inert gas atmosphere or under vacuum to obtain a mixture B c) heating the mixture B under an inert gas atmosphere to chemically react magnesium powder with nano 3:10 ₂ , 4 nm SiO ₂ reduction Silicon

d) 酸洗去除反应副产物 Mg0、未反应的镁和可溶性杂质； d) pickling removes reaction by-product Mg0, unreacted magnesium and soluble impurities;

e) 在惰性气体气氛或真空条件下加热使纳米硅颗粒与碳在介面进一歩发 ^ 反应，将纳米硅颗粒通过化学成键固定在碳的 a-b基面。 e) heating in an inert gas atmosphere or under vacuum to cause the nano-silicon particles to react with carbon in the interface, and the nano-silicon particles are fixed to the a-b base of the carbon by chemical bonding.

11.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述纳米 Si0₂为气相法白炭黑，包括表面改性后的白炭黑。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the nano-SiO ₂ is a fumed silica, and comprises surface-modified white carbon black.

12.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述纳米 Si0₂的直径在 lnm到 200nm之间。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the nano-SiO _{2 has} a diameter of between 1 nm and 200 nm.

13.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述纳米 Si0₂的直径在 5nm到 lOOnm之间。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the nano-SiO _{2 has} a diameter of between 5 nm and 100 nm.

14.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述纳米 Si0₂的直径在 5nm到 50nm之间。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the nano-SiO _{2 has} a diameter of between 5 nm and 50 nm.

15.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述歩骤 a)中的混合包括机械混合或者先将 3:10₂负载到碳表面，然后再 f 镁粉混合。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the mixing in the step a) comprises mechanical mixing or first loading 3:10 ₂ onto the carbon surface, and then f Magnesium powder is mixed.

16.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述纳米 Si0₂同碳的重量比例在 2 : 5到 4: 1之间。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the weight ratio of the nano-SiO ₂ to carbon is between 2:5 and 4:1.

17.根据权利要求 10所述的碳负载的纳米硅颗粒结构的制备方法，其特征于，所述纳米 Si0₂同碳的重量比例在 1 : 2到 2: 1之间。 The method for preparing a carbon-loaded nano-silicon particle structure according to claim 10, wherein the weight ratio of the nano-SiO ₂ to carbon is between 1:2 and 2:1.

18.—种不对称超级电容，包括高比表面活性炭阳极、隔离阴极和阳膜、电解液以及阴极，其特征在于：所述的阴极采用权利要求 1 所述碳负载的纳米硅颗粒结构。 18. - Asymmetric supercapacitors, including high specific surface activated carbon anodes, isolated cathodes and anodes The film, the electrolyte, and the cathode are characterized in that: the cathode is a carbon-loaded nano-silicon particle structure according to claim 1.

19.一种锂离子电池，包括复合氧化物阳极、阴极、隔离阴极和阳极的隔膜以及电解液，其特征在于：所述阴极采用权利要求 1 所述碳负载的纳米硅颗粒 A lithium ion battery comprising a composite oxide anode, a cathode, a separator for isolating a cathode and an anode, and an electrolyte, characterized in that: the cathode is a carbon-loaded nano-silicon particle according to claim 1.