共查询到17条相似文献,搜索用时 46 毫秒
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采用循环伏安法在活性炭电极(AC)表面合成导电聚苯胺,得到聚苯胺修饰活性炭复合电极(PAn/AC),通过循环伏安(CV)、恒流充放电技术研究了电极的电容特性,并计算了其等效串联电阻。结果表明,在硫酸溶液中,复合电极呈现较好的电容特性,复合电极的比电容能达到545F/g,比纯活性炭电极的306F/g提高了78%,不同放电电流密度下求出的比电容比纯活性炭电极平均提高了89%,且复合电极的ESR比AC电极稍小。 相似文献
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超级电容器用活性炭的制备与电化学表征 总被引:1,自引:0,他引:1
以煤焦油沥青为前驱体,采用化学活化法制备了超级电容器用高比表面活性炭和活性炭电极.考察了活化温度对活性炭电极比电容量的影响,研究了活性炭材料的比表面积和孔结构与活性炭电极的充放电性能之间的关系,并对活性碳电极进行了电化学表征.结果表明,在500~700℃,随着活化温度的提高,活性炭电极的比电容量显著增大,当活化温度超过700℃时,活性炭电极材料的比电容量变化不明显.700℃活化温度下所制备的活性炭材料呈现明显的多孔结构,孔容为1.038cm3/g,比表面积为1959m2/g;所制成的活性炭电极比电容量为210F/g,等效内阻为0.9Ω/cm2,10mA/cm2充放电500次后保持90%以上电容量,交流阻抗谱在频率低于转化点时表现出纯粹的电容行为,循环伏安曲线显示出良好的可逆特性. 相似文献
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超级电容器用沥青焦基活性炭的制备及其电化学性能 总被引:14,自引:9,他引:14
采用沥青焦为原料,制备了系列高比表面积活性炭作为超级电容器电极材料。用直流循环充放电、循环伏安及交流阻抗等表征方法比较了沥青焦基超级活性炭和日本可乐丽公司YPl5活性炭的电化学性能。实验结果表明在KOH、H2SO4、(C2H5)4NBF4/碳酸丙烯酯(Propylenecarbonate PC)及(C2H5)4NBF4/乙腈(Acetonitrile)体系中,沥青焦基活性炭的比电容随比表面积增加,其最高值分别为257F/g、228F/g、140F/g、142F/g,均超过了日本活性炭。沥青焦基活性炭电极在KOH体系中的等效串联电阻的体积电阻率与日本炭相差不大;在H2SO4体系中的电阻率均小于日本活性炭;在碳酸丙烯酯体系中的电阻率均大于日本活性炭;在乙腈体系中,活化剂KOH与沥青焦比例为4:l、经800℃活化3h制备的活性炭的电阻率小于日本活性炭。 相似文献
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用醋酸锰和高锰酸钾制备二氧化锰粉末;用氯化钌和氢氧化钠制备水合二氧化钌粉末。以二氧化钌和二氧化锰作为电极材料的活性物质,以活性碳粉末为电极的基础原料制备复合电极,并组装超级电容器单元。用x射线衍射仪和扫描电镜对电极材料进行表征,可得复合电极具有明显的电容特征。在浓度为38%的硫酸电解质溶液中,对复合电极进行电化学性能测试,循环伏安曲线、充放电曲线和交流阻抗特性显示了复合电极材料具有良好的电化学性能。碳,锰复合电极的比容量为128F/g,碳/锰/钌复合电极的比容量为266F/g。当二氧化钌和二氧化锰在电极中质量比各占20%时,更能发挥活性物质的作用,由该电极材料组成的超级电容器具有理想的电容特性。 相似文献
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超级电容器聚苯胺/活性中间相炭微球复合电极材料的研究 总被引:1,自引:0,他引:1
以具有高比表面积的活性中间相活性碳微球(a-MCMB)、苯胺(ANI)为主要原料,过硫酸铵为氧化剂,通过原位化学聚合法在a-MCMB表面沉积聚苯胺(PANI),首次制得纳米PANI/a-MCMB新型复合材料,通过XRD、SEM对样品的晶型结构和表面形貌进行表征,并将得到的复合材料组装成超级电容器,用循环伏安、交流阻抗、恒流充放电以及循环性能测试技术对该材料进行电化学测试。结果显示,在1MH2SO4溶液中,复合材料的比容量达到288.46F/g。 相似文献
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超级电容器作为一种新兴储能设备,具有充电速度快、功率密度高、使用寿命长、工作温度范围广且绿色环保等优点,弥补了以锂电池为代表的传统化学电池和其他普通电容器在生产使用方面的不足。本工作以生活废弃物柚子皮为碳源,利用生物质热解炭化技术,在氮气保护下高温碳化柚子皮得到活性炭材料,然后采用最优质量比1∶1原位聚合制备活性炭/聚苯胺纳米复合材料,经高温再碳化获得活性炭材料,并将获得的活性炭材料制成电极,研究其电化学性能。结果表明,活性炭/聚苯胺复合材料经碳化后获得的活性炭材料比电容量可达358 F/g,电极经过2 000次的充放电循环后,电容量仍可保持初始值的95%,具有优良的循环稳定性。 相似文献
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通过原位化学聚合制备了不同形貌的纳米炭材料(炭黑,碳纳米管及石墨烯纳米片)/聚苯胺复合电极材料.分析表明:石墨烯/聚苯胺复合材料相比于炭黑/聚苯胺、碳纳米管/聚苯胺复合物及纯聚苯胺,具有产率和比容量高,内阻低及明显提高的循环稳定性和倍率性能.石墨烯/聚苯胺复合材料更好的电化学性能归因于:(a)二维平面结构石墨烯有利于大量聚苯胺在其表面均匀沉积及更多的活性位使聚苯胺和电解液离子接触,从而有利于聚苯胺得失电子促使氧化还原反应的顺利进行;(b)石墨烯间的面接触有利于构建电子的快速传输网络使电极材料具有更低的电阻;(c)石墨烯及聚苯胺层层堆叠结构具有柔性包覆限制作用,可有效防止聚苯胺在充放电过程中因膨胀和收缩而从石墨烯表面脱离. 相似文献
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Valter Bavastrello Tercio Bezerra Correia TerencioLuca Belmonte Pierluigi CossariClaudio Nicolini 《Thin solid films》2012,520(18):5877-5883
Poly(o-methoxyaniline) and poly(o-methylaniline) were synthesized by oxidative polymerization in the presence of multi-walled carbon nanotubes (MWNT) for the fabrication of chloroform processable nanocomposites obtained by embedding MWNT in the polymer matrix without the formation of covalent bonds. The study of pressure-area isotherms highlighted different substituents along the aromatic rings affected the packing grade of macromolecules when spreading on different subphases in relation to the associated sterical hindrance. The presence of MWNT inside the polymer matrix showed to favor a more stretched conformation of macromolecules with a subsequent increment of area/molecule values with respect to the corresponding pure conducting polymers. Furthermore, the sterical hindrance affected the nanocomposite electrochemical properties and conducting polymers containing less hindering substituents along the aromatic rings turned out to be faster electrochemical systems. Less hindering substituents were also able to enhance the conducting properties of nanocomposite materials in association with MWNT. 相似文献
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Polyaniline (PANI)/activated carbon (AC) composites were prepared by a chemical oxidation polymerization. To find an optimum ratio between PANI and AC which shows superior electrochemical properties, the preparation was carried out in changing the amount of added aniline monomers. The morphology of prepared composites was investigated by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The structural and thermal properties were investigated by Fourier transform infrared spectra (FT-IR) and thermal gravimetric analysis (TGA), respectively. The electrochemical properties were characterized by cyclic voltammetry (CV). Composites showed a summation of capacitances that consisted of two origins. One is double-layer capacitance by ACs and the other is faradic capacitance by redox reaction of PANI. Fiber-like PANIs are coated on the surface of ACs and they contribute to the large surface for redox reaction. The vacancy among fibers provided the better diffusion and accessibility of ion. High capacitances of composites were originated from the network structure having vacancy made by PANI fibers. It was found that the composite prepared with 5 ml of aniline monomer and 0.25 g of AC showed the highest capacitance. Capacitance of 771 F/g was obtained at a scan rate of 5 mV/s. 相似文献
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We demonstrated a simple and environment-friendly method in thepreparation of N-doped carbon/PANI(NCP)composite without binder.The structureand the property of NCP have been characterized by XPS,IR,XRD,SEM,CV,GCD and EIS.The results reveal that NCP has high capacitance performance of up to 615 F·g-1at 0.6A·g-1.Additionally,the asymmetric NCP300/lcarbon supercapacitor delivers a highcapacitance(111 F·g-1at 1A·g-1)and a capacity retention rate of 82%after 1200 cyclesat 2A·g-1.The ASC cell could deliver a high energy density of 39.1 W·h·kg-1at a powerdensity of 792.6 W·kg-1. 相似文献
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Rose M Korenblit Y Kockrick E Borchardt L Oschatz M Kaskel S Yushin G 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(8):1108-1117
Ordered mesoporous carbide-derived carbon (OM-CDC) materials produced by nanocasting of ordered mesoporous silica templates are characterized by a bimodal pore size distribution with a high ratio of micropores. The micropores result in outstanding adsorption capacities and the well-defined mesopores facilitate enhanced kinetics in adsorption processes. Here, for the first time, a systematic study is presented, in which the effects of synthesis temperature on the electrochemical performance of these materials in supercapacitors based on a 1 M aqueous solution of sulfuric acid and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid are reported. Cyclic voltammetry shows the specific capacitance of the OM-CDC materials exceeds 200 F g(-1) in the aqueous electrolyte and 185 F g(-1) in the ionic liquid, when measured in a symmetric configuration in voltage ranges of up to 0.6 and 2 V, respectively. The ordered mesoporous channels in the produced OM-CDC materials serve as ion-highways and allow for very fast ionic transport into the bulk of the OM-CDC particles. At room temperature the enhanced ion transport leads to 75% and 90% of the capacitance retention at current densities in excess of ~10 A g(-1) in ionic liquid and aqueous electrolytes, respectively. The supercapacitors based on 250-300 μm OM-CDC electrodes demonstrate an operating frequency of up to 7 Hz in aqueous electrolyte. The combination of high specific capacitance and outstanding rate capabilities of the OM-CDC materials is unmatched by state-of-the art activated carbons and strictly microporous CDC materials. 相似文献
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无定型氧化锰超级电容器电极材料 总被引:9,自引:0,他引:9
采用化学共沉淀法制备超级电容器用氧化锰电极材料,借助X射线衍射(XRD)、扫描电子显微镜(SEM)、红外光谱(FT-IR)和BET比表面积分析手段对样品进行表征。结果表明,产物为无定型结构,粒径分布较均匀,约在40~50nm,BET比表面积达到160.5m^2/g。在0.5mol/LK2SO4水溶液中,电位窗口为0~0.8V(vs.SCE)内,通过循环伏安和恒流充放电测试,显示该材料制备的电极具有良好的电容行为和功率特性。在扫描速度为4mV/s时,单电极的比容量达到140F/g。 相似文献