SAS对镍铝水滑石材料超级电容性能的影响

减小电极活性物质晶粒和颗粒尺寸对提高电化学性能具有重要作用.采用共沉淀法通过控制十二烷基磺酸钠(SAS)的添加量合成镍铝水滑石(NiAl-LDHs)电极材料,通过X射线衍射仪、扫描电镜表征电极材料的晶粒尺寸和颗粒尺寸形态,通过电化学工作站测试电化学性能,研究发现:随着SAS添加量增大,镍铝水滑石晶粒尺寸逐渐减小,SAS添加8 mmol时最小,达到2.2 nm;颗粒随着SAS增加更为疏松,尺寸逐渐减小,团聚趋势减小.比电容随着SAS加入量增大逐渐增大.添加SAS 8 mmol的样品在电流密度1 A/g时具有最大比电容953 F/g,在5 A/g电流密度下循环1000圈后比电容仍保持初始值的45.8％,表现出较好的电化学性能.     

纤维状介孔碳材料的制备及超级电容性能的研究

以间苯二酚-甲醛树脂为碳源,十六烷基三甲基溴化铵为表面活性剂,九水硅酸钠为助剂,制备纤维状介孔碳材料。采用扫描和透射电子显微镜对样品进行表征,表明样品具有纤维状形貌并存在无序介孔结构;氮气吸附脱附测试结果表明,样品具有较高的比表面积(1 257 m~2/g),均一的介孔(4.0 nm);电化学测试结果表明,当电流密度为1 A/g时,其比电容为158.5 F/g,具有良好的电容性能和循环稳定性,可作为电极材料应用于超级电容器中。     

片状与颗粒状CoMn2O4电极材料的制备及电化学性能

分别以纯水、50%(体积分数,下同)纯水与50%乙醇混合溶液、乙醇为溶剂制备了CoMn_2O_4纳米电极材料,研究了溶剂对CoMn_2O_4材料形貌、微观结构及电化学性能的影响。结果表明:采用纯水为溶剂制备的CoMn_2O_4材料具有片状结构,在电流密度为1 A/g时,比电容为446 F/g,在电流密度为5 A/g条件下,1 000次充放电循环后电容保持率为77%;50%纯水加50%乙醇为溶剂制备的CoMn_2O_4材料具有颗粒与片状混合结构,在电流密度为1 A/g时,比电容为684 F/g,在电流密度为5 A/g条件下,1 000次充放电循环后电容保持率为81%;采用乙醇为溶剂制备CoMn_2O_4材料具有颗粒状多孔结构,在电流密度1 A/g条件下,比电容为850 F/g,在电流密度为5 A/g条件下,1 000次充放电循环后电容保持率达86%,乙醇为溶剂制备的颗粒状多孔的CoMn_2O_4材料表现出更为优异的超电容性能。     

氧化镍/还原氧化石墨烯复合物的制备及其在超级电容器中的应用

通过正负纳米片之间的静电吸引并热处理,有效合成了NiO/还原氧化石墨烯复合物,对样品进行了形貌、结构表征以及相应的电化学性能测试。研究结果表明,合成NiO/rGO的最佳质量比为m(NiO)∶m(rGO)=85∶15;复合物与纯NiO相比片状变薄,团聚现象有了明显改善。对样品进行循环伏安以及放电测试:最佳质量比的复合物在1 A/g时,比电容达到670 F/g,与纯材料相比比电容有了很大的提高。并且该复合材料在15 A/g时产物的比电容为486 F/g,其比电容是电流密度为1 A/g时的72.5%,具有良好的电化学性能。     

乙二醇辅助合成镍钴氢氧化物及其电化学性能研究

本文一步溶剂热法合成纳米镍钴氢氧化物电极材料,利用乙二醇、CTAB辅助自组装纳米结构的生成。采用扫描电镜(SEM)、红外光谱(FT-IR)、X射线衍射(XRD)技术手段对样品进行表征。在6 mol/L KOH电解液中,利用三电极体系中利用循环伏安法、计时电位法测试检测电化学性能,在1 A/g电流密度下比电容达1384 F/g。     

一种独特玫瑰花形貌N掺杂的CNTs/MoS2材料的制备及电化学性能探究

用简单的水热反应合成一种形貌独特的玫瑰花状的N-CNTs/MoS2纳米复合材料.通过一系列的表征手段和化学工作站分析该材料的组成和结构并得出其电化学性能.结果表明:该材料作为电极材料时,在电流密度为1 A/g时,比电容为642 F/g;在电流密度为10 A/g时,比电容为280 F/g,且在5000次循环之后比电容仍能保持在85.8％,而MoS2材料在同等条件下仅有56.2％的电容保持率,因此N-CNTs/MoS2纳米复合材料具有优良的电化学性能.     

纤维状介孔碳材料的制备及超级电容性能的研究

以间苯二酚-甲醛树脂为碳源,十六烷基三甲基溴化铵为表面活性剂,九水硅酸钠为助剂,制备纤维状介孔碳材料。采用扫描和透射电子显微镜对样品进行表征,表明样品具有纤维状形貌并存在无序介孔结构;氮气吸附脱附测试结果表明,样品具有较高的比表面积(1 257 m²/g),均一的介孔(4.0 nm);电化学测试结果表明,当电流密度为1 A/g时,其比电容为158.5 F/g,具有良好的电容性能和循环稳定性,可作为电极材料应用于超级电容器中。     

普鲁士蓝镶嵌聚吡咯薄膜电极的制备及其电化学电容性质的研究

为提高聚吡咯电极材料电化学性能，研制出一种普鲁士蓝(PB)镶嵌聚吡咯(PPy)薄膜电化学电容器电极。采用化学沉淀法结合气相聚合(VPP)法将同步合成的PB引入PPy薄膜中，制备了自支撑聚吡咯/普鲁士蓝(PPy/PB)复合电极材料。利用扫描电子显微镜、拉曼光谱、X射线粉末衍射技术等对复合材料的形貌及结构进行表征。在三电极体系和对称超级电容器中研究PPy/PB复合材料的电化学表现，研究结果表明，PPy/PB复合材料组装的超级电容器比电容高达447.6 F/g。不同电流密度下充放电性能研究表明，电流密度从1.0 A/g增大到10.0 A/g时，PPy/PB比容量保持率为70.8%,具有优异的倍率性能。通过4 000次恒流充放电后PPy/PB电容保持率为76.9%,高于纯PPy电极材料，显示出较好的电容性能。     

KCl模板法制备煤沥青基活性炭及其电化学性能

以煤沥青为前驱体,以KCl为模板剂,采用KOH直接活化法制备了超级电容器用活性炭。研究了KCl添加量对活性炭比表面积、孔径分布及电化学性能的影响。结果表明:适当的KCl添加量有利于改善活性炭的孔径分布,而且有利于提高活性炭的微孔比例,活性炭的微孔比例最高达到81.19%;KCl与沥青、KOH添加比例为1∶1∶4时,所制备的活性炭具有最佳的电化学性能,充放电电流密度为0.5 A/g时,比电容达到220.6 F/g,电流密度增加到5 A/g时,比电容保持率为82.15%。     

CoNiO_(2)/Ti_(3)C_(2)Tx复合材料的制备及其电化学性能EI北大核心CSCD

采用共沉淀方法并结合热处理技术制备了CoNi O_(2)/Ti_(3)C_(2)Tx复合材料。使用扫描电子显微镜、X射线衍射、X射线光电子能谱、氮气吸脱附测试、循环伏安法、恒流充放电法和电化学阻抗测试对所制备样品进行表征。结果表明:CoNiO_(2)/Ti_(3)C_(2)Tx质量比为30:1的复合材料具有最佳的电化学性能,在1 A/g的电流密度下具有389 F/g的比电容,约为Ti_(3)C_(2)Tx比电容的6倍;当电流密度为20 A/g时,其比电容为309 F/g;在电流密度为10 A/g时,经过1500次充放电循环后,电容保持率为82%。     

氢氧化钾活化烟杆制造活性炭及表征

以烟杆为原料,氢氧化钾为活化剂,采用一步炭化法制备了活性炭。采用正交实验研究了对活性炭得率和吸附性能的影响的主要因素,得到了最佳工艺条件,所制活性炭碘吸附值为1198.27 mg/g,亚甲基蓝吸附值为国家一级品标准的3倍。还测定了该活性炭的氮吸附等温线,通过H-K方程和密度函数理论表征了活性炭的孔结构,其结果与电子探针和透射电镜分析的活性炭微观结构相一致。     

工艺参数对天然沸石模板多孔炭结构的影响

以内蒙古赤峰市的天然沸石矿为模板，以蔗糖为炭的前驱体，制备了具有较窄中孔孔径分布的模板多孔炭。利用SEM、XRD及N2吸附等方法对模板炭进行了表征。采用BJH法分析了模板炭的孔径分布特征。研究了制备工艺中催化剂H2SO4的用量和炭化温度对所得模板多孔炭结构的影响。结果表明，硫酸用置和炭化温度对模板多孔炭的表面形貌、微晶结构和孔结构都有一定的影响。催化剂H2SO4用置过多时模板炭表面结构粗糙、致密，杂质较多，比表面积和总孔容较小；炭化温度越高，模板炭的结构收缩越严重，总孔容和中孔孔容越大，中孔率越高。     

Template Synthesis of Three-Dimensional Cubic Ordered Mesoporous Carbon With Tunable Pore Sizes

Three-dimensional cubic ordered mesoporous carbons with tunable pore sizes have been synthesized by using cubic Ia3d mesoporous KIT-6 silica as the hard template and boric acid as the pore expanding agent. The prepared ordered mesoporous carbons were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption analysis. The results show that the pore sizes of the prepared ordered mesoporous carbons with three-dimensional cubic structure can be regulated in the range of 3.9–9.4 nm. A simplified model was proposed to analyze the tailored pore sizes of the prepared ordered mesoporous carbons on the basis of the structural parameters of the silica template.     

Co-gelation synthesis of porous graphitic carbons with high surface area and their applications

An easy co-gelation route has been developed to synthesize porous graphitic carbons with high surface areas by using teraethylorthosilicate (TEOS), furfuryl alcohol (FA), and metal nitrates as precursors. Using a one-pot co-gelation process, a polyfurfuryl alcohol–silica interpenetrating framework with metal ions uniformly dispersed was formed during the polymerization of FA and the hydrolysis of TEOS within an ethanol solution of the three precursors. This synthesis process is simple and time-saving in comparison with the conventional preparation methods. During the heat treatment, Fe₇Co₃ alloy nanoparticles were produced by carbothermal reduction and they then catalyzed the graphitization of the amorphous carbon. The graphitic carbons obtained have a high crystallinity as shown by X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy analysis. The degree of graphitization can be controlled by the varying the loading amount of catalyst. The porous texture of the carbons combines miropores and bimodal mesopores, mainly originating from the silica template formed with different sizes and the loose packing of the graphite sheets. The carbons have large surface areas (up to 909 m²/g) and exhibit excellent electrochemical performance.     

Synthesis of nanostructured SiC by magnesiothermal reduction of silica from zeolite ZSM-5 and carbon: The effect of carbons from different sources

Nanostructured SiC was synthesized by magnesiothermal reduction of silica derived from zeolite ZSM-5 with a Si/Al ratio of about 80 and four carbons from different sources. The carbons were carbon black and three carbons synthesized by impregnating furfuryl alcohol or sucrose into three porous templates (ZSM-5, clinoptilolite and MCM-48). Magnesiothermal reduction was carried out by reacting mixtures of silica, carbon and magnesium powder at 600–800 °C in a flowing argon atmosphere. The starting materials and final products were characterized by X-Ray diffraction, thermogravimetric analysis, scanning electron microscopy and BET analysis. The results indicated that the synthesis of nanostructured SiC is influenced by the chemical nature of the carbon and its surface area.     

Preparation of macroporous carbons from phase-inversion membranes

Preparation of porous carbons from phase-inversion membranes was investigated as a control method of pore structure in carbon materials. The structure in carbon films was estimated by means of electron microscopy, mercury porosimetry, and gas-adsorption methods. When phase-inversion membranes of Kapton-type polyimide were carbonized, they maintained the film form and gave macroporous carbon films having high porosity. However, micro- and mesopore structures in the carbon films were not influenced by phase inversion in the polymer stage, and, thus, the macroporous carbons had a molecular sieve property similar to that of carbons prepared from nonporous polyimide films. A macroporous structure in cellulose membranes was similarly maintained through the carbonization step, but some of these were fractured or deformed owing to the large shrinkage. Polymer membranes have a capability as porous carbon precursors if they satisfy two requirements: solid-state carbonization and relatively high carbon yield. A composite membrane of a macroporous carbon with a dense carbon having an impervious ability was readily produced by shaping at the precursor stage. © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of microporous carbons templated by ammonium-form zeolite Y

Emerging applications such as gas storage require porous carbon materials with tailored structural and surface properties. Template synthesis approach to porous carbons offers opportunities for tailoring these properties. In this study, ammonium-form zeolite Y (NH₄Y) was used as a template and furfuryl alcohol (FA) was employed as a carbon precursor to prepare microporous carbons by simple impregnation method. The effects of synthesis conditions such as carbonization temperatures and heating rates on the pore structure of the microporous carbons were investigated. The thermal behaviors of FA-NH₄Y mixtures and zeolite/carbon composites were studied by thermogravimetric analysis (TGA). The physical, structural, and surface properties of the microporous carbons were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), elemental analysis, and physical adsorption of nitrogen. Microporous carbons with high surface areas, pore volumes and nitrogen-containing surface functional groups can be readily synthesized.     

珊瑚状氮掺杂多孔碳的制备及其超电容性能

在三聚氰胺为氮源、碳酸钾为活化剂的条件下,由菜籽饼制得了珊瑚状氮掺杂分级多孔碳(CNPCs)。采用场发射扫描电子显微镜、透射电子显微镜、X射线光电子能谱、氮吸脱附等表征手段,研究了三聚氰胺的用量对CNPCs微观形貌、组成及孔隙结构的影响。结果表明,当三聚氰胺的用量为2 g时,所得CNPC2的比表面积达2050 m2·g-1。以6 mol·L-1KOH为电解液,在0.05 A·g-1的电流密度下,CNPCs的比容可达274 F·g-1;当电流密度为50 A·g-1时,CNPCs的比容为169 F·g-1,显示了优异的倍率性能。经过10000次充放电测试后,比容保持率达96%,展现了良好的循环稳定性。此工作为从生物质大规模生产高性能储能用多孔碳材料提供了一种简单、绿色的方法。     

Porous carbon/carbon composites produced from carbon black and petroleum pitch

Granular porous carbon/carbon composites were prepared by mixing carbon black, petroleum pitch and a solvent, followed by granulating the mixture and carbonization of the resulting pellets in an inert atmosphere. The pore structure of this material is studied by mercury porosimetry and scanning electron microscopy. Based on the obtained results, a model for it is proposed. The effects of carbon black type used, filler/binder ratio, heat treatment temperature and mixing time on surface area, total pore volume and strength of the finished pellets were investigated. Comparison with activated carbons indicates that the investigated material can find industrial applications as a catalyst support and as an adsorbent for adsorption of large molecules due to the meso- and macroporous structure and low ash content.     

Pore size-controlled synthesis of 3D hierarchical porous carbon materials for lithium-ion batteries

3D hierarchical porous carbons (3DCs) with different pore size distributions are prepared by using Ni(OH)₂ as template. The morphology, crystalline features, pore structure and surface composition of the hierarchical porous carbons are characterized using various analytic techniques including scanning electron microscopy, transmission electron microscopy, N₂ physical adsorption, powder X-ray diffraction and X-ray photoelectron spectroscopy. It is found that the pore size distributions of the 3DCs play an important role in the lithium-storage capacity when they are used as anode materials for rechargeable lithium-ion batteries. The typical sample 3DC-20 has a specific reversible capacity of 630 mAh g^??1 in the first cycle and and 363 mAh g^??1 after 50 cycles. The high capacity of 3DC-20 can be attributed to the existence of the largest amount of micropores with 0.6–0.9 nm pore width, which increase the lithium storage capacity; in addition, the existence of mesoporous and macroporous effectively shortens the distance for charge diffusion, the turbostratic graphite structure low resistance for electron conduction.