共查询到19条相似文献,搜索用时 187 毫秒
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采用脉冲电沉积法,于苯胺、浓硫酸和碳纳米管(CNTs)的混合溶液中,制备得到PANI(聚苯胺)/CNTs复合物,并对所制PANI/CNTs复合材料的微观形貌、结构以及电化学性能进行了研究。结果表明,CNTs的加入增大了PANI/CNTs复合物的比表面积,提高了其导电性。PANI/CNTs复合物用作超级电容器电极材料时,其比容量可达420.7 F/g,经500次循环后衰减幅度为8.9%,表现出优良的电化学性能。 相似文献
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为满足轻薄化、柔性化和可穿戴化电子产品对柔性储能器件的需求,运用静电纺丝技术与滚筒接收方法得到PAN/MnCl2复合纳米纤维膜,再经特定装置加捻、预氧化、碳化生成复合碳纳米纤维束CNFs/MnO2,利用恒电位沉积方法在其表面形成一层聚苯胺PANI,制备了以CNFs/MnO2/PANI为电极材料的线状超级电容器,搭建三电极测试体系平台,运用恒流充放电、循环伏安法测试,数据显示本方法制备的超级电容器比容量可达到 142.31F/g,且具有一定的柔韧性和循环性。 相似文献
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以橄榄石型磷酸亚铁锂(LiFePO4)为正极,活性炭(AC)为负极,制备了LiFePO4/AC混合超级电容器。通过充放电、倍率和漏电流测试,系统研究了所制混合超级电容器的电化学性能。结果表明,在正负极活性物质质量比为0.8∶1.0的条件下,混合超级电容器综合性能最佳:比容量为25.38 mAh.g–1,比能量为3.21 Wh.kg–1,分别是活性炭超级电容器的2.83倍和2.17倍,且在大倍率充放电下循环稳定性好、漏电流小,在1600 s后漏电流为0.25 mA。 相似文献
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《电子元件与材料》2017,(3):31-37
采用湿法球磨制备了锂离子电池用混合正极材料LiNi0.5Co0.2Mn0.3O2/LiFePO4。通过X射线衍射(XRD)和扫描电镜(SEM)表征了材料的结构和形貌,采用恒流充放电测试、循环伏安测试(CV)和电化学阻抗谱测试(EIS)方法研究了混合正极材料LiNi0.5Co0.2Mn0.3O2/LiFePO4的电化学性能。结果表明:混合正极材料LiNi0.5Co0.2Mn0.3O2/LiFePO4的晶体结构完好,碳包覆的纳米LiFePO4颗粒较好地包覆在LiNi0.5Co0.2Mn0.3O2表面。含质量分数15% LiFePO4的混合正极材料LiNi0.5Co0.2Mn0.3O2/LiFePO4电化学性能优良,0.2C首次充放电比容量为181.40 mAh?g–1,首次充放电效率为90.79%;1.0C循环50次后放电比容量为169.89 mAh?g–1,容量保持率为97.80%;3.0C循环5次后的放电比容量为162.22 mAh?g–1,容量保持率仍有89.43%;60 ℃高温存储7 d后,容量保持率和容量恢复率分别为86.48%和97.32%。 相似文献
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MnFe类普鲁士蓝(MnHCF)作为超级电容器电极材料具有高比电容和优良的循环稳定性,但导电性不佳限制了其应用,通过将其与聚苯胺等高电导率材料复合可以极大改善这一问题。传统的两步制备方法工艺繁琐,干扰因素较多。本研究利用MnO_2纳米棒作原材料在室温下一步合成了聚苯胺-MnFe类普鲁士蓝复合材料(PANI-MnHCF)。利用X射线衍射仪(XRD)、傅里叶红外光谱仪(FTIR)、扫描电子显微镜(SEM)对样品进行物理表征,使用循环伏安法(CV)、恒电流充放电法以及交流阻抗法(EIS)对样品电化学性能进行测试。结果表明:成功合成了堆砌为规则块状结构的PANI-MnHCF。在0.5 mol/L中性Na_2SO_4电解液中,1 A/g电流密度下,比电容达276.4 F/g;电流密度增大至5 A/g后,比电容仍能保持225.2 F/g;2000次充放电循环测试后,容量保持率为70.2%。 相似文献
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聚苯胺混杂型电化学电容器研究 总被引:4,自引:1,他引:3
采用聚苯胺在改性活性炭表面原位聚合方法,制备了聚苯胺活性炭复合物。研究了活性炭与苯胺在不同配比下制得的复合物的比容量,结果表明:当活性炭占复合材料的质量比为14.9%时,复合物的比容量为191.8F/g,比相同条件下制得聚苯胺的比容量提高了56%。以该复合物为电化学电容器的正极材料,以改性活性炭为其负极材料,电解液为6mol/L的氢氧化钠水溶液,组装了原型电化学电容器。该电容器的比能量可达8.7Wh/kg,比功率可达878W/kg。 相似文献
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Xueying Chang Maher F. El-Kady Ailun Huang Cheng-Wei Lin Stephanie Aguilar Mackenzie Anderson Jason Zi Jie Zhu Richard B. Kaner 《Advanced functional materials》2021,31(32):2102397
The conducting polymer polyaniline (PANI) has been considered to be a promising pseudocapacitive electrode material for supercapacitors due to its high specific capacitance, low cost, and environmental friendliness. However, the poor cycling stability of PANI during the charge–discharge processes limits its widespread practical application. Herein, a facile synthetic method is demonstrated for covalently grafting an aniline tetramer (TANI), the basic building block of PANI, onto 3D graphene networks via perfluorophenylazide coupling chemistry to create a hybrid electrode material for ultralong-life supercapacitors. The design, which substitutes long-chain PANI with short-chain TANI and introduces covalent linkages between TANI and 3D graphene, greatly enhances the charge–discharge cycling stability of PANI-based supercapacitors. The electrode material, as well as the fabricated symmetric all-solid-state supercapacitors, exhibit extraordinary long cycle life (>85% capacitance retention after 30 000 charge–discharge cycles). The capacitance can be further boosted through fast and reversible redox reactions on the electrode surface using a redox-active electrolyte while maintaining outstanding cycling stability (82% capacitance retention after 100 000 cycles for a symmetric all-solid-state device). While conducting polymers are known to be limited by their poor cycling stability, this work provides an effective strategy to achieve enhanced cycle life for conducting polymer-based energy storage devices. 相似文献
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有机双电层电容器用活性炭电极的修饰 总被引:5,自引:2,他引:3
利用石墨、炭黑、碳纳米管三种导电碳材料,对高比表面积活性炭进行掺杂修饰,制备有机电解液双电层电容器用薄膜电极。经电化学测试发现,在 1 mol/L 的 LiPF6/EC-DEC(体积比 1∶1)溶液中,经不同导电材料修饰后的活性炭电极,其单电极比容量和大电流充放电性能均有较大改善。其中,掺杂 10%(质量分数)碳纳米管的活性炭电极,在 330 mA/g 电流密度下的单电极比容量可达 81 F/g,比未掺杂活性炭电极 60 F/g 的比容量提高了 35%;电流密度从 60 mA/g 增至 330 mA/g,该电极的容量保持率为 79.4%。 相似文献
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电荷泵中浮置电容是影响输出特性的关键因素,针对大容量浮置电容难以集成的问题,提出利用电流传输器构成有源电容倍增器代替浮置电容的方法,可使等效的浮置电容容量提高1~3个数量级.利用PSPICE软件对反压及倍压电荷泵分别在采用有源电容倍增器和理想电容的情况下进行仿真,对比分析的结果说明采用有源电容倍增器的电荷泵电路仅需要很小的电容就能得到与外加大容量浮置电容电荷泵电路相同的输出特性(实例中100pF可等效50nF),从而基于有源电容倍增器的电荷泵将更易于全单片集成. 相似文献
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Soumen Giri Debasis Ghosh Asish Malas Chapal Kumar Das 《Journal of Electronic Materials》2013,42(8):2595-2605
Supercapacitors have evolved as the premier choice of the era for storing huge amounts of charge in the field of energy storage devices, but it is still necessary to enhance their performance to meet the increasing requirements of future systems. This could be achieved either through advancing the interfaces of the material at the nanoscale or by using novel material compositions. We report a high-performance material composition prepared by combining a transition metal (palladium)-doped conductive polymer with multiwalled carbon nanotubes (MWCNTs). MWCNTs/palladium-doped polyaniline (MWCNTs/Pd/PANI) composites and multiwalled carbon nanotube/polyaniline (MWCNTs/PANI) composites (for comparison) were prepared via in situ oxidative polymerization of aniline monomer. The reported composites were characterized by Fourier-transform infrared (FTIR), x-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) studies. FESEM and TEM studies indicated the narrow size distribution of the π-conjugated polymer-protected palladium nanoparticles on the surface of the carbon nanotubes. All the electrochemical characterizations were executed using a three-electrode system in 1 M H2SO4 electrolyte. Cyclic voltammetry (CV) analysis was performed to observe the capacitive performance and redox behavior of the composites. The ion transfer behavior and cyclic stability of the composites were investigated by electrochemical impedance spectroscopy (EIS) analysis and cyclic charge–discharge (CCD) testing, respectively. The MWCNTs/Pd/PANI composite was found to exhibit an especially high specific capacitance value of 920 F/g at scan rate of 2 mV/s. 相似文献
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In this paper, the author presents a new methodology for measuring the gate drain capacitance of CMOS devices using an accelerated dc measurement scheme. The gate-drain capacitance was measured using a floating gate MOS transistor, i.e., an MOS transistor with an additional capacitor placed in series with the gate oxide capacitance. This was implemented within a standard p-well CMOS process using two matched transistors. The top capacitance couples charge onto the gate oxide capacitor and the gate-drain capacitor. The amount of coupling is determined by the ratio of these two capacitors 相似文献