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1.
石墨可以在高电势下电化学可逆存储阴离子,有望在高电压储能器件中担当正极材料.本文介绍了基于阴离子-石墨嵌层化合物型正极材料的高比能电容器的研究进展,剖析了影响电容器性能的各方面因素,探讨了一系列表征相关电极材料储能机制的方法和手段,揭示了溶剂化效应对阴离子插嵌石墨正极电化学行为的关键性作用.并进一步概述了该种正极材料近年来在新型储能器件-双离子电池中的发展态势,展望了其应用前景和即将面临的潜在问题.  相似文献   

2.
利用KOH活化制得了酚醛基活性碳纤维(ACF).研磨后形成细颗粒酚醛基活性碳纤维材料(P-ACF).对比研究P-ACF与ACF在6 mol·L-1 KOH溶液中的电化学性能,结果表明:P-ACF电极表现出更佳的电容性质,比电容达200 F·g-1,大电流放电比电容衰减速率较慢,其微孔离子迁移电阻(Rp,2.96Ω)较ACF的(4.65Ω)小.研磨可增加ACF的断面暴露量,降低纤维间接触电阻和微孔内离子迁移电阻.  相似文献   

3.
赵立平  齐力  王宏宇 《应用化学》2013,30(10):1189-1193
以三氧化钼(MoO3)作为负极材料,活性炭(AC)作为正极材料,组成混合型电化学电容器.研究电容器在1 mol/L NaPF6的碳酸丙烯酯(PC)中的电化学性能,其电位窗为0~3V,能量密度和功率密度分达到33.0 W·h/kg和595.6W/kg,经1000次循环后容量为第20次的93.8%,库仑效率在经过20次循环后到95.1%以上.  相似文献   

4.
利用高温氨解还原氧化钒(V2O5)制备了氮化钒(VN)纳米材料. 采用XRD、SEM与TEM观察分析样品的结构和形貌,采用氮气吸附、循环伏安曲线以及恒流充放电曲线测试样品的比表面积、孔径分布和电极电化学性能. 结果表明,VN样品属于立方晶系(Fm3m [225]),其大小均一,近似球形,氨解时间的加长(12 h),小颗粒间相互交联可形成一定的介孔. 50 mA?g-1电流密度下VN-c电极的比电容能达到192 F.g-1,1000周期循环其比电容仍有150 F.g-1,同时具有双电层电容性能和氧化还原反应的准电容性能.  相似文献   

5.
以高性能活性炭作为负极材料, 将颗粒平均粒径为40~60 nm的纳米钴氧化物干凝胶作为正极材料组成电化学电容器, 研究了电容器在7 mol/L的KOH水溶液中的电化学性能, 其充放电电压可以达到1.4~1.6 V, 以材料本身重量计算的比能量和比功率分别达到15.4 W·h/kg和23.5 kW/kg.  相似文献   

6.
电化学电容器中二氧化锰电极材料研究进展   总被引:2,自引:0,他引:2  
本文在简介MnO2电极材料的性质和特点基础上,重点介绍近5年来国内外有关MnO2电极材料在合成及电化学电容器应用领域中的最新进展,及未来可能的发展方向。  相似文献   

7.
8.
采用磷酸活化和磷酸改性制备了不同种类的含磷活性炭,采用元素分析、X射线光电子能谱(XPS)和氮气吸附等手段分析了活性炭的元素含量、表面化学性质和孔隙结构,采用恒电流充放电、循环伏安和交流阻抗分别考察了活性炭在KOH和H2SO4电解质溶液中作为超级电容器电极材料的电化学性能,采用自由截距多元线性回归拟合统计分析研究了活性炭电极比电容量的影响因素,应用三电极体系分析了磷元素对活性炭电化学性能的影响机理。研究结果表明,活性炭掺杂的磷引入了赝电容,提高了活性炭电极的比电容量,磷元素含量为5.88%(w)的活性炭的比电容量在0.1 A·g-1下达到185 F·g-1。统计分析结果显示,活性炭的中孔有利于电解质离子向微孔内的扩散。在6 mol·L-1 KOH电解质溶液中,孔径在1.10-1.61 nm、2.12-2.43nm及3.94-4.37 nm范围内是电解质离子在活性炭孔隙内部形成双电层的主要场所;在1 mol·L-1 H2SO4电解质溶液中,孔径在0.67-0.72 nm范围内有利于双电层电容的形成。  相似文献   

9.
电化学双电层电容器用新型炭材料及其应用前景   总被引:4,自引:0,他引:4  
张浩  曹高萍  杨裕生  徐斌  张文峰 《化学进展》2008,20(10):1495-1500
活性炭是目前使用最为广泛的一种电化学双电层电容器(EDLC)的电极材料,但其固有的缺点制约了EDLC性能的进一步提高。用新型高性能炭电极材料可使EDLC比能量和比功率性能进一步提高。这些新型炭材料包括基于石墨层状结构的纳米门炭,基于碳纳米管阵列结构的毛皮炭,通过高温置换反应制备的骨架炭以及电极可整体成型的纳米孔玻态炭。本文介绍了这些炭材料的电化学特性及其在电化学双电层电容器中的应用,指出用这4种新型炭材料制备EDLC的比能量或比功率性能远高于目前活性炭基EDLC,具有良好的应用前景。  相似文献   

10.
Chemically modified ordered mesoporous carbon CMK-3 materials were prepared by means of an easy wet-oxidative method in 2 mol/L nitric acid aqueous solution. A large amount of oxygen-containing functional groups were introduced onto the CMK-3 surface. Modified CMK-3(m-CMK-3) and aniline monomer were polymerized via an in situ chemical oxidative polymerization method. Morphological characterizations of m-CMK-3/PANI (polyaniline) composites were carried out via field emission scanning electron microscopy(SEM)...  相似文献   

11.
Polyaniline (PA) film was chemically deposited onto the surface of activated carbon (AC) uniformly. Chemical deposition was carried out in 0.1 mol/L aniline plus 0.5 mol/L H2SO4 solution adopting V2O5·nH2O coated on the surface of activated carbon as oxidant. The surface morphologies and structures of the composite materials were characterized by scanning electron microscopy and FT-IR spectra. The electrochemical properties of the composite material electrodes were studied by cyclic voltammetry and constant current charge/discharge tests in 1 molFL H2SO4 solutions. The specific capacitance of composite materials was exhibited as high as 237.5 F/g at a current density of 1.0 A/g compared with a value of 120 F/g for pure carbon electrode. Good power characteristic and good stability of composite electrodes were also demonstrated.  相似文献   

12.
Theoretical and Experimental Chemistry - Modern design approaches to electric energy storage devices based on nanostructured electrode materials, in particular, electrochemical double layer...  相似文献   

13.
超细氧化钌超电容器电极材料的制备   总被引:4,自引:0,他引:4  
本文采用利用氯化钌和碳酸氢氨为反应前驱体,溶胶凝胶方法制备了超细氧化钌材料。将材料在250℃下加热脱水处理后,材料具有良好的表面特性和最大电化学比容量570F·g-1。当脱水温度在300℃以上时,氧化钌材料明显晶化,同时材料比容量迅速降低。本文还测试了不同温度处理后材料的等效串联电阻和法拉第电化学阻抗特性,实验证明250℃条件下处理的电极材料具有最低的等效串联阻抗和良好的功率特性。当制备氧化钌过程中掺加适量碳纳米管形成复合材料时,电极材料的功率特性得到明显的改善。  相似文献   

14.
Novel, porous NiCo2O4 nanotubes (NCO‐NTs) are prepared by a single‐spinneret electrospinning technique followed by calcination in air. The obtained NCO‐NTs display a one‐dimensional architecture with a porous structure and hollow interiors. The effect of precursor concentration on the morphologies of the products is investigated. Due to their unique structure, the prepared NCO‐NT electrode exhibits a high specific capacitance (1647 F g?1 at 1 A g?1), excellent rate capability (77.3 % capacity retention at 25 A g?1), and outstanding cycling stability (6.4 % loss after 3000 cycles), which indicates it has great potential for high‐performance electrochemical capacitors. The desirable enhanced capacitive performance of NCO‐NTs can be attributed to the relatively large specific surface area of these porous and hollow one‐dimensional nanostructures.  相似文献   

15.
合成路径对超级电容器用二氧化锰性质的影响   总被引:2,自引:0,他引:2  
万传云  王利军  沈绍典  朱贤 《化学学报》2009,67(14):1559-1565
研究了不同合成路径对二氧化锰结构及电化学性能的影响. 路径1为将0.15 mol/L醋酸锰溶液加入到0.1 mol/L高锰酸钾溶液中; 路径2中, 物料的加料方式与路径1相反. X射线衍射和扫描电镜测试表明合成的产物均为无定型α-MnO2, 晶粒尺寸为200~300 nm. 氮吸附曲线测试结果表明: 路径1所得的二氧化锰具有较大的比表面积(329 m2/g), 其孔径分布比较均一, 孔径6~12 nm, 孔体积较小(0.45 cm3/g); 路径2所得的二氧化锰比表面积较小(298 m2/g), 具有从微孔到大孔的连续分布孔, 平均孔径11.4 nm, 孔体积较大(0.66 cm3/g). 交流阻抗和循环伏安电化学测试结果显示: 路径2所得样品具有较大的法拉第阻抗, 在较低扫描速度下(2 mV•s-1), 其比电容(203 F•g-1)比路径1所得MnO2高(189 F•g-1), 路径1所得二氧化锰的比电容随扫描速度变化的趋势较小. 恒流充放电测试显示路径1合成的二氧化锰具有较好的功率特性. 在2 A•g-1的电流密度下, 其比容量为0.1 A•g-1电流密度下的96.3%, 而路径1的样品的容量保持率为92.5%. 造成上述结果差异的原因是由于不同合成路径导致二氧化锰存在不同的孔结构特征所致.  相似文献   

16.
High-frequency responsive electrochemical capacitors (ECs), which can directly convert alternating current (AC) to direct current (DC), are getting more essential for the rapid development of electronic devices. In order to satisfy the requirements of ECs with fast rate capability and appreciable capacitance density, numerous efforts have been made towards the preparation and design of the electrode material, which is a decisive factor in the performance of ECs. Carbon-related electrode materials have been widely shown to significantly increase the performance of ECs because of their light weight, high strength, and high processability. In this concept, the latest advances in the rational design and controllable fabrication of carbon-related electrode materials, including planar 2D materials, random 3D, and vertical carbon materials are summarized. Moreover, the state of the art of carbon-based ECs is discussed from the viewpoint of the structure of the electrode and performance of ECs. Finally, this concept presents integrated perspectives on the further design and preparation of carbon related ECs.  相似文献   

17.
Russian Journal of Electrochemistry - Nickel–potassium hexacyanoferrate (KNiHCF) and its analogues (NaKNiHCF) with different Na : K ratio are synthesized by chemical coprecipitation....  相似文献   

18.
以豌豆荚为碳源、ZnCl2或KOH为活化剂制备了活性炭, 并用作双电层电容器的电极材料. 采用比表面及孔隙度分析仪表征了豌豆荚基活性炭的孔结构. 通过KOH或ZnCl2活化后, 活性炭比表面积从1.69 m2·g-1增大到2237或621 m2·g-1. 采用循环伏安法和恒流充放电测试技术表征了豌豆荚基活性炭的电化学特性. 结果表明: 在6 mol·L-1 KOH溶液中经KOH活化处理的活性炭的质量比电容高达297.5 F·g-1, 并具有良好的充放电稳定性, 在5 A·g-1的高电流密度下循环充放电500次后, 质量比电容仅衰减8.6%.  相似文献   

19.
李娟  崔利 《应用化学》2011,28(3):297-301
在聚苯胺(PANI)和二氧化锰(MnO2)存在的条件下,以FeCl3/甲基橙为模板,通过化学氧化法聚合吡咯(Py)单体,制备MnO2/PPy/PANI纳米管复合材料。 利用X射线衍射、透射电子显微镜、红外光谱和电化学测试等多种测试技术对复合材料进行物性表征和电化学电容性能测试,并讨论了不同含量的PANI对复合物材料的结构和性能的影响。 结果表明,由于PANI、MnO2与PPy三者的相互协同作用,以及材料管状结构的大比表面积,使三元复合材料具有比二元复合材料要大的电化学活性。 所合成的三元复合材料最大比容量达到458.4 F/g。  相似文献   

20.
Partially reduced graphite oxide was prepared from graphite oxide by using synthetic graphite as precursor. The reduction of graphite oxide with a layer distance of 0.57 nm resulted in a reduction of the layer distance depending on the degree of reduction. Simultaneously the amount of oxygen functionalities in the graphite oxide was reduced, which was corroborated by elemental analysis and EDX. The electrochemical activation of the partially reduced graphite oxide was investigated for tetraethylammonium tetrafluoroborate in acetonitrile and in propylene carbonate. The activation potential depends significantly on the degree of reduction, that is, on the graphene‐layer distance and on the solvent used. The activation potential decreased with increasing layer distance for both positive and negative activation. The resulting capacitance after activation was found to be affected by the layer distance, the oxygen functionalities and the used electrolyte. For a layer distance of 0.43 nm and with acetonitrile as the solvent, a differential capacitance of 220 Fg?1 was achieved for the discharge of the positive electrode near the open‐circuit potential and 195 Fg?1 in a symmetric full‐cell assembly.  相似文献   

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