基于聚多巴胺的氮掺杂碳材料的制备及其电化学性能

多孔碳材料由于高的比表面积、优异的电子传导率、良好的化学稳定性等优点在超级电容器电极材料领域被广泛研究。 碳材料的组成及表面孔结构直接影响其电化学性能,为进一步提高碳材料的电容性能,本文首次以聚多巴胺球为前体,KOH为活化剂,通过高温碳化成功制备了良好电化学性能的氮掺杂多孔碳材料。 通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、 X射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)和Raman光谱等对所制备的氮掺杂多孔碳材料进行了形貌及结构组成的表征。 在6 mol/L KOH电解液中, 采用循环伏安、恒电流充放电对多孔碳材料的电化学性能进行了研究。 结果表明,由于双电层电容和赝电容的协同作用,在电流密度为1 A/g时,材料的比电容可达269 F/g,充放电循环1000圈后电容仍可保留初始值的93.5%。     

锂离子电池负极材料纳米多孔硅/石墨/碳复合微球的制备与性能

以硅藻土为原料, 通过镁热还原反应得到多孔硅, 进一步利用砂磨得到纳米多孔硅, 然后通过球磨将其与片状石墨和沥青均匀混合, 采用喷雾干燥技术造粒, 高温煅烧后制备了纳米多孔硅/石墨/碳复合微球. 对所得复合微球的结构和理化性质进行了表征. 纳米多孔硅/石墨/碳复合微球作为锂离子电池负极材料展示出较高的可逆容量、 优异的循环稳定性(100次循环后容量仍为790 mA·h/g, 容量保持率可达96.7%)及较好的倍率性能.     

纳米锡/硬碳复合材料作为嵌锂负极的研究

利用金属铁和钴纳米颗粒的催化活化作用,制备了多孔硬碳球.应用聚焦离子束切割技术,观察到扩孔后的硬碳球中充满彼此连通的发达中孔.在此多孔硬碳球中填入纳米锡(Sn)颗粒,对复合材料的电化学性能进行了测试.     

氢氧化钾活化制备超级电容器多孔碳电极材料

具有高比表面积、良好导电性的多孔碳材料在超级电容器中有着广泛的应用前景. 大量的研究工作致力于通过物理或者化学手段合成并调控多孔材料的微观结构. 在众多多孔碳材料的制备方式中,氢氧化钾作为一种高效的活化剂,常用于制备具有良好孔径分布和高比表面积多孔碳电极材料. 本文主要结合作者课题组的研究工作,着重概述利用氢氧化钾活化sp²碳纳米材料制备多孔碳材料的机理过程、结构形貌的转变以及所得材料的电化学性能,希望对发展新型的高性能基多孔碳材料的超级电容器电极材料有所帮助.     

用金属生物大分子配合物前驱体制备多孔碳球及其电化学性能

以天然生物大分子鞣花酸(EA)为有机配体,Zn(CH_3COO)_2·2H_2O为锌源,N-甲基吡咯烷酮为溶剂,在室温下经超分子自组装形成金属生物大分子配合物(Zn EA)前驱体,再经碳化制备了分级多孔碳球.研究了不同碳化温度和酸洗处理过程对多孔碳球的结构、形貌、比表面积和电化学储能的影响.结果表明,在惰性气氛下,1000℃下碳化制备的多孔碳材料(C-Zn EA-1000)的比表面积高达1238 m~2/g,最可几孔径分布约为4 nm;在6 mol/L KOH电解液中,扫描速率为5 m V/s时比电容为216 F/g.当扫描速率由5 m V/s增加到100 m V/s时,其比电容保持率为84.67%,显示了优异的倍率特性.在1 A/g的电流密度下,经过5000周充放电循环后比电容的损失仅为3%,具有优异的循环稳定性.     

混合盐活化胖大海基多孔炭的制备及超级电容器电极材料性能

利用浸泡后的胖大海为碳源, 氯化锌和氯化锂混合盐作为活化剂, 采用炭化胖大海(PC-1)、添加氯化锌(PC-2)或添加氯化锌/氯化锂(PC-3)的胖大海的方法制备了3种多孔碳材料, 并通过三电极体系测试电极材料的电化学性能。结果表明, 3种碳材料在电流密度为0.5 A/g的比电容分别为69、132和228 F/g; 当电流密度增加至10 A/g时, PC-3的比电容仍高达166 F/g, 具有良好的倍率性能。该实验表明, 通过氯化锌/氯化锂复合盐活化胖大海分级多孔碳可作为高性能超级电容器电极材料。     

自活化乌拉草基多孔碳的制备和电化学性质

以乌拉草为原料,采用直接碳化方法,通过热解过程中前驱体自活化(即利用自身包含的活化剂实现分子内的化学活化),并经过必要的除杂过程制备了多孔碳材料Ula C-950-HF.测试了该多孔碳的电化学性质,并与以几种常见的生物质为原料制备的多孔碳材料及商用活性炭的电化学性质进行对比.结果表明,乌拉草基多孔碳材料Ula C-950-HF的电容值为113 F/g,经过4000次循环后,材料的电容值仅降低了4 F/g,显示出用作超级电容器电极材料的潜力.     

硫在不同碳载体材料中的电化学性能研究

为了探索碳载体材料结构对于硫的电化学性能的影响,本文通过高温固相法将升华硫与石墨烯、导电炭黑、多孔碳等三种不同结构的碳载体材料复合,制备得到硫含量相近的三种硫碳复合材料. 通过电镜扫描、低温氮吸附、X射线衍射等方法,对所制备的硫碳复合材料的结构和硫的分布状态进行了表征和分析. 并进一步对三种复合材料进行了电化学性能测试,结果表明,硫负载到多孔碳中的电化学性能最好,其初始放电比容量达到了1623.2 mA·h·g^-1,循环100周之后,其放电比容量仍能保持在845 mA·h·g^-1. 这主要因为相比于石墨烯的层状结构和导电炭黑的链状结构,多孔碳材料中含有大量的微孔和介孔,负载硫后,与硫分子的接触面积大,活性物质的利用率高,从而提高了硫的电化学性能.     

一步碳化多孔有机材料制备多孔碳及其性能的研究

开发并利用清洁的、可再生的能源是解决环境污染问题和能源短缺的有效方法.碳化含碳量较高的多孔有机材料制备的多孔碳,具有较高的比表面积,良好的物化稳定性,优良的机械性能等优点,在清洁能源的存储、分离、能量的存储与转化领域有广泛的应用.常见的由多孔有机材料制备多孔碳的方法主要是非活化碳化法和活化碳化法.不同的制备方法得到的多孔碳形貌,孔结构各不形同.多孔碳材料自身的结构性质可以影响其应用.合理的设计并调控多孔碳的“孔”,发挥孔尺寸的“筛分效应”可以有效地对气体进行存储和分离.在锂电等能量转化领域,“限域效应”是影响锂电性能的重要因素.多孔碳材料中较小的孔可以限域活性成分,而较大的孔可以快速传输,两种孔的协同效应可以使锂电性能大大提升.本综述系统地归纳了一步碳化多孔有机材料制备多孔碳的方法及其优势,详细地介绍了其在气体吸附、存储、分离以及电化学等领域的应用.最后,结合多孔碳材料的研究现状,提出由多孔有机材料制备多孔碳材料所面临的挑战,同时也展望了多孔碳材料的应用前景.     

空心碳半球锂离子电池负极的高倍率性能研究

以聚苯乙烯球为模板,通过水热法包裹硬碳层,又用微波法迅速引发聚苯乙烯核裂解的两步反应,制备了高比表面的空心碳半球.采用扫描电镜和透射电镜观察材料形貌,并测试该负极的电化学性能.在高倍率充放电条件下,与石墨、中间相碳微球电极相比,空心碳半球显现出了更高的容量和优异的寿命.     

Hierarchical porous carbon derived from rice straw for lithium ion batteries with high-rate performance

Porous carbons with a high surface area have been prepared from rice straw. The hierarchical porous network with large macroporous channels and micropores within the channel walls enable the porous carbons to provide the pathways for easy accessibility of electrolytes and fast transportation of lithium ions. These porous carbons which show a particular large reversible capacity are proved to be promising anode materials for high-rate and high-capacity lithium ion batteries.     

Li-ion charge storage performance of wood-derived carbon fibers@MnO as a battery anode

Wood-derived carbons have been demonstrated to have large specific capacities as the anode materials of lithium-ion batteries(LIBs). However, these carbons generally show low tap density and minor volumetric capacity because of high specific surface area and pore volume. Combination with metal oxide is one of the expected methods to alleviate the obstacles of wood-derived carbons. In this work, the composites of Mn O loaded wood-derived carbon fibers(CF@Mn O) were prepared via a simple and envir...     

由微孔棒状羟基磷灰石为模板合成的新型层次孔炭材料的电化学电容性能

电化学电容器已经成为极具潜力的可满足高功率需求的储能系统器件. 多孔炭具有大比表面积、高导电性、化学惰性、廉价及可调孔结构等优势, 因此成为电化学电容器最为常用的电极材料. 本文报道由微孔棒状羟基磷灰石为模板及蔗糖为碳源合成的新型具有层次孔道结构的孔炭材料的电化学电容器的性能. 采用X射线衍射分析仪、扫描电子显微镜、透射电子显微镜、X射线光电子能谱及BET表面分析仪表征了合成的多孔炭的形貌及表面特性. 采用循环伏安法、交流阻抗图谱分析及恒流充放电评价多孔炭材料在1 mol·L^-1硫酸中的电化学电容性能. 多孔炭具有高的比表面积(719.7 m²·g^-1)和大的孔容(1.32 cm³·g^-1), 其无序的孔道由任意分布的微孔、坍塌的中孔及类模板形状的相互交织的棒状中孔组成. 随着炭化温度的增加, 微孔及棒状中孔的密度随之降低, 在炭化温度高达900℃时, 孔径分布图上出现了三个峰. 正是由于这些特殊的结构特征, 由900℃炭化得到的多孔炭制成的电极展示出很好的电化学电容性能.     

Effects of raw material texture and activation manner on surface area of porous carbons derived from biomass resources

Porous carbons have been prepared from biomass resources, such as cornstalks, rice straws, pine needles and pinecone hulls, through a simple carbonization and KOH solution activation process. The pore sizes of the obtained porous carbons are mainly distributed in the range of 1-2 nm, whereas the surface areas of the materials vary from 1000 to more than 3000 m(2) g(-1) depending on the raw materials and preparation conditions. It is found that the biomass texture and the activation manner play key roles in determination of surface areas of the porous carbons. In addition, the amount of activation agent, the activation temperature and the activation time also affect the surface area of the porous carbons but to a less extent. The obtained porous carbons with high surface areas show good performance when used as Pt-catalyst supports for cinanamaldehyde hydrogenation.     

Characterization of Microporous Activated Carbon Electrodes for Electric Double-layer Capacitors

IntroductionElectric double layer capacitors( EDLCs) witha high power density can be used as memory back-up devices or electric vehicles.EDLCs store energyin the electric double layer by charge accumulationon the interface between the electrode and the elec-trolyte. In order to obtain reasonable energies andpower densities,the more suitable material forEDLCs musthave a high surface area with a signif-icant value of specific double layer capacitance,better pore size distribution and electro…     

稻壳多孔碳材料的电容性能及模型计算

采用NaOH和H₃PO₄化学活化法, 由廉价的稻壳制备了2种高比表面积的介孔活性碳, 测试了其比表面积和平均孔径, 利用循环伏安、 恒流充放电和交流阻抗测试了其电化学性能, 其比电容分别达到145.8和168.5 F/g. 利用一种多分支的三级孔道模型对其进行交流阻抗谱拟合, 拟合结果符合度较高, 表明该模型对分析活性碳电极结构有一定指导意义.     

New phosphorus-containing spherical carbon adsorbents as promising materials in drug adsorption and release

A simple method of preparation of new high surface area spherical carbon adsorbents is presented. The phosphoric acid activation upon hydrothermally formed spherules was employed to produce carbons having controlled high specific surface area (over 2100m(2)/g), large volumes of pores (1.2cm(3)/g), and high acidity. Prepared from sucrose materials show high adsorption capacities (i.e. 220mg/g(C)) toward paracetamol. It is proved that for these materials the contents of surface phosphorus are responsible for the reversibility of drug adsorption/release process.     

Modification of Activated Carbon Fibers and Their Characterizes of Adsorption for Xenon

Activated carbon fibers (ACFs) are characterizes by their highly developed internal surface area and porosity. Especially the development of micro- and mesopores is of great importance because it allows the carbons to adsorb large amounts and various types of chemicals from gases or liquids. Due to such a valuable feature, activated carbon fibers have been in use for many years. Porous carbon materials have now become extremely versatile adsorbents of major industrial significance. The high surface area and porosity of activated carbon fibers are the result of the activation process; physical or chemical activation. However, the complexity of the carbon structure, although voluminous research has been done and great effort has been made toward the control of pore size and its distribution^[1-3]. The recent development of industrial technology provides new application fields for porous carbons and,at the same time, requires the carbon to have a desired pore structure. To meet such a requirement, many novel approaches to control pore structure have been proposed.