SnO2/石墨纳米片复合电极及其在超级电容器中的应用

在电场的作用下对石墨棒进行电化学剥离, 使其表面形成相互平行排列, 且垂直于石墨棒基底的二维(2D)石墨纳米片阵列(GNSA). 然后通过阴极还原电沉积法制备SnO₂/石墨纳米片阵列(SnO₂/GNSA)复合电极.采用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)和傅里叶变换红外(FT-IR)光谱对其形貌和结构进行了表征.电化学测试表明该复合电极具有优异的超电容性能, 在0.5 mol·L^-1 LiNO₃电解质中, 扫描速率为5 mV·s^-1, 电位窗口为1.4 V时, 比电容达4015 F·m^-2. 由SnO₂/GNSA复合电极和相同电解质组装成的对称型超级电容器, 在扫描速率为5 mV·s^-1时, 其电位窗口可增至1.8 V, 能量密度达到0.41 Wh·m^-2, 循环5000 圈后其比电容仍保持为初始比电容的81%.     

氧化钌/石墨纳米片复合阵列电极的制备及其电容性能

通过电化学剥离法在石墨棒表面构筑了层数不等、彼此平行且垂直于基底的二维石墨纳米片(GNS)阵列, 而后采用阴极还原电沉积法在GNSs 表面均匀地包覆了一层氧化钌(RuO₂·xH₂O)薄膜, 形成了RuO₂·xH₂O/GNS 复合阵列电极. 电化学测试表明, RuO₂·xH₂O/GNS 复合阵列电极具有优良的超电容性能, 在0.5mol·L^-1 H₂SO₄电解质溶液中, 扫描速率为5 mV·s^-1, 电位窗口为0.9 V时, 其比电容高达4226 F·m^-2, 并且具有优异的循环性能, 经过20000圈充放电循环后, 电容保持率高达94.18%.     

超级电容器电极材料MnO_2纳米棒的制备及其电化学性能(英文)

以洋葱碳为还原剂,KMnO4为氧化剂,稀硫酸溶液为溶剂,采用水热法一步制备MnO2纳米棒.利用X射线衍射仪和透射电子显微镜分析了MnO2纳米棒的物相、结构、形貌;将MnO2纳米棒作为电极材料组装了超级电容器,采用电池测试系统测定了超级电容器的电化学性能.结果表明,所得到的产物为α-MnO2,其直径为5~10nm,长度为50~100nm;以MnO2纳米棒作为电极材料组装的超级电容器具有较高的比容量和稳定性,有望在超级电容器的研究和应用中得到推广.     

TiO_2纳米管阵列的多重改性及其在超级电容器中应用的最新进展

阳极氧化法制备的TiO_2纳米管阵列因其简单的制备方法、可控的形貌以及环境友好等优点而成为超级电容器领域重点研究的电极材料之一。本文介绍了TiO_2纳米管的多重改性方法,包括引入氧空位、金属或非金属修饰或掺杂、金属化合物(氧化物、氢氧化物、硫化物、氮化物)以及导电聚合物修饰等,以进一步提高TiO_2纳米管的电化学性能。介绍了近年来阳极氧化法制备的TiO_2纳米管阵列在超级电容器中应用的研究进展,为进一步拓展TiO_2纳米管阵列的实际应用提供参考。     

镍掺杂花状纳米碳片的制备及其在超级电容器中的应用

本文通过溶剂热法"一锅"制备了镍掺杂的花状纳米碳片(Ni/FCNAs)。借助X射线衍射仪(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)对该复合材料的表面形貌和结构进行了分析。循环伏安和恒流充/放电测试结果表明,Ni/FCNAs具有较大的比电容值且电化学稳定性良好。在电流密度为0.1 A.g-1时,Ni/FCNAs电极的比电容可达176 F.g-1。本文同时也提出了Ni/FCNAs可能的形成机理。     

石墨—聚四氟乙烯复合涂层电极的研制及应用

由导电相与绝缘相构成的复合电极在流动体系中具有高的响应电流和高的信噪比．聚多氯乙烯类高分子材料具有高的化学稳定性和憎水及憎油性，是理想的构成复合电极的材料．多年来已有一些文献［’－’j报道了用这类材料制作复合电极的方法，但均为模压成型法，制得的电权均为尺寸较大的盘状或块状电极，将此电极用于流通体系往往需要精密设计和加工流通池，很不方便．我们曾用复合镀的方法制备过铜“‘和钻［’怕9聚四氟乙烯复合电极，但这种方法不适用于以石墨为导电相的聚四氟乙烯复合电极的制备．本文报道了采用涂层的方法制备此种电极的技…     

Sn掺杂二氧化锰超级电容器电极材料

用化学液相法制备了超级电容器用的Sn掺杂二氧化锰电极材料. 采用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)光谱对电极材料的形貌和物相进行表征. 结果表明, 所得样品由直径约10 nm, 长约100 nm的棒状物粘结成200-500 nm的球状物, 晶型为δ-MnO2. 循环伏安、电化学交流阻抗和恒流充放电测试表明, 化学掺杂的比例对材料的电化学性能有较大的影响. 当Mn:Sn的摩尔比为50:1时, 电极材料的比电容达到293 F·g-1, 比未掺杂的提高了64.6%. 600次充放电循环后, 比电容稳定在275 F·g-1, 表现出良好的容量保持能力.     

基于NiCo2O4纳米片电极的非对称混合电容器

The looming global energy crisis and ever-increasing energy demands have catalyzed the development of renewable energy storage systems. In this regard, supercapacitors (SCs) have attracted widespread attention because of their advantageous attributes such as high power density, excellent cycle stability, and environmental friendliness. However, SCs exhibit low energy density and it is important to optimize electrode materials to improve the overall performance of these devices. Among the various electrode materials available, spinel nickel cobaltate (NiCo₂O₄) is particularly interesting because of its excellent theoretical capacitance. Based on the understanding that the performances of the electrode materials strongly depend on their morphologies and structures, in this study, we successfully synthesized NiCo₂O₄ nanosheets on Ni foam via a simple hydrothermal route followed by calcination. The structures and morphologies of the as-synthesized products were characterized by X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller (BET) surface area analysis, and the results showed that they were uniformly distributed on the Ni foam support. The surface chemical states of the elements in the samples were identified by X-ray photoelectron spectroscopy. The as-synthesized NiCo₂O₄ products were then tested as cathode materials for supercapacitors in a traditional three-electrode system. The electrochemical performances of the NiCo₂O₄ electrode materials were studied and the area capacitance was found to be 1.26 C·cm^-2 at a current density of 1 mA·cm^-2. Furthermore, outstanding cycling stability with 97.6% retention of the initial discharge capacitance after 10000 cycles and excellent rate performance (67.5% capacitance retention with the current density from 1 to 14 mA·cm^-2) were achieved. It was found that the Ni foam supporting the NiCo₂O₄ nanosheets increased the conductivity of the electrode materials. However, it is worth noting that the contribution of nickel foam to the areal capacitance of the electrode materials was almost zero during the charge and discharge processes. To further investigate the practical application of the as-synthesized NiCo₂O₄ nanosheets-based electrode, a device was assembled with the as-prepared samples as the positive electrode and active carbon (AC) as the negative electrode. The assembled supercapacitor showed energy densities of 0.14 and 0.09 Wh·cm^-3 at 1.56 and 4.5 W·cm^-3, respectively. Furthermore, it was able to maintain 95% of its initial specific capacitance after 10000 cycles. The excellent electrochemical performance of the NiCo₂O₄ nanosheets could be ascribed to their unique spatial structure composed of interconnected ultrathin nanosheets, which facilitated electron transportation and ion penetration, suggesting their potential applications as electrode materials for high performance supercapacitors. The present synthetic route can be extended to other ternary transition metal oxides/sulfides for future energy storage devices and systems.     

NiS2纳米片的制备及其在非对称超级电容器中的应用

本文采用牺牲模板法,以Ni(OH)₂作为前驱体制备NiS₂. 通过对NiS₂进行XRD、EDS、BET、SEM及TEM等表征来研究NiS₂的元素组成及结构形貌. SEM及TEM结果显示前驱体及NiS₂均为纳米片结构. 电化学测试结果表明NiS₂存在着优秀的电容性能,在电流密度为1 A·g^-1时,NiS₂比电容能够达到1067.3 F·g^-1,同时具有高的倍率特性. 为了进一步探究NiS₂作为电活性材料的实用性,以NiS₂作为阳极材料,活性炭（AC）作为阴极组装成非对称超级电容器,在功率密度为0.8 kW·kg^-1,能量密度高达38.4 Wh·kg^-1,并且在3000次恒流充放电后,比电容依然保持93.7%.     

柔性超级电容器电极材料与器件研究进展

超级电容器,也称电化学电容器,它具有比锂离子电池更高的功率密度和更长的循环寿命,与此同时,其能量密度也高于传统的电介质电容器,因此成为了一类具有很大应用前景的能量储存设备。随着人们对智能电子设备性能要求的提高,各类柔性可穿戴电子设备相继出现,柔性超级电容器作为一类便携式能量储存设备也受到了许多研究者的关注。在持续的研究中,二维平面结构的柔性超级电容器得到较大发展并日益成熟,与此同时,随着对柔性电子设备可穿戴性能要求的提高,一维纤维结构的柔性超级电容器应运而生,并且得到了初步发展。本文首先介绍了超级电容器的储能原理和重要性能的评估方法;接着,重点概述了二维平面结构和一维纤维结构两类柔性超级电容器器件结构和电极材料的研究进展;最后,总结了两类柔性超级电容器仍然存在并亟待解决的问题以及未来发展所面临的关键技术挑战,期望能为柔性超级电容器的研究提供参考和借鉴。     

纳米结构SnO_2/碳纳米管复合电极的制备及其储锂性能

在含有十二烷基硫酸钠和SnCl2.2H2O的乙二醇溶液中加入纯化的碳纳米管,于160℃加热制备SnO2/CNTs复合材料,并以XRD,HRTEM,SEM等方法表征该材料的物相结构和表面形貌.结果表明SnO2纳米粒子均匀地覆盖在碳纳米管上,粒径小于10 nm.以其作为电极材料与锂片组装成扣式电池,恒流充放电测试.显示以该材料作为锂离子电池负极材料具有较高的比容量和良好的循环性能.     

二氧化锰/球形活性炭复合材料在有机系超级电容器中的应用

以Mn(NO3)2和中间相炭微球基球形活性炭（MSAC）为原料,采用热分解的方法成功制备了一种新型超级电容器用MnO2/MSAC球形复合材料。 通过X射线衍射、扫描电子显微镜和透射电子显微镜对比分析了该复合材料的结构和形貌,并采用循环伏安、恒流充放电、电化学阻抗（EIS）、循环充放电研究了电极的电化学性能。 结果表明,MnO2/MSAC球形复合物中的MnO2粒径为100~160 nm;在1 mol/L的LiPF6/(DMC+EC)（EC：乙烯碳酸酯;DMC：碳酸二甲酯) 有机电解液中MnO2/MSAC复合材料所组装的电容器的工作电压可达3.0 V,在0.002 A/cm2电流密度下,MnO2/MSAC球形复合材料的电容器和单纯MSAC材料的电容器的首次循环比容量分别为186和167 F/g,在循环过程中,MnO2/MSAC球形复合材料的电容器循环200次后充放电的库仑效率基本保持在95%以上。 此外,MnO2/MSAC球形复合材料的充放电曲线表现出典型的电容行为;循环伏安曲线也表现出良好矩型特征,同时具有较高的能量密度和良好的功率性能。     

复合纳米粒子SnO2/CdS的制备及性能研究

由湿化学方法制备了包覆型SnO2 /CdS复合纳米粒子 .用ICP、XRD及TEM测定了样品的组成和平均晶粒尺寸 ,并通过HRTEM直接观察到样品的包覆结构 .与纯SnO2 纳米粒子相比较 ,SnO2 /CdS复合纳米粒子在波长为 36 0 - 5 80nm范围内有更强的吸收 ;由该复合纳米粒子制得的电极呈现出良好的光电转换特性 ,其最大IPCE值达 40 .9% ,远大于纯SnO2 纳米电极的IPCE( 0 .6 5 % ) ,而且光响应范围也从纯SnO2 的 30 0 - 4 0 0nm拓展到 30 0 - 5 5 0nm .     

Amperometric Detection of 4‐Chlorophenol on Two Types of Expanded Graphite Based Composite Electrodes

The assessment of an expanded graphite‐Ag‐zeolite‐epoxy composite (EG‐Z‐Ag‐Epoxy) electrode for the determination of 4‐chlorophenol (4‐CP) is described and compared to the corresponding expanded graphite‐epoxy composite (EG‐Epoxy) electrode. Cyclic voltammetry was used to characterize the electrochemical behavior and determination of 4‐CP at both electrodes in 0.1 M Na₂SO₄ and 0.1 M NaOH supporting electrolytes. A substantial enhancement of sensitivity for the determination of 4‐CP at the EG‐Z‐Ag‐Epoxy electrode was reached by applying a chemical preconcentration step prior to voltammetric quantification. Also, under these last conditions the lowest limit of detection of 1 μM illustrates the analytical versatility of this electrode in a concentration range where aquatic 4‐chlorophenol pollution is known to occur.     

Composite Electrode SnO2／TiO2 for Dye-Sensitized Solar Cells

Composite nanoporous electrode SnO2/TiO2 was fabricated for the dye sensitized solar cell (DSSC) with N3 (Cis-Ru). After introducing of TiO2, the open-circuit photovoltage (Voc) was higher than that of the pure SnO2 electrode, while short-circuit photocurrent (Isc) was varied with the ratio of the TiO2. Appropriate content of the TiO2 can be beneficial to the efficiency of the solar cell, and it gives negative impact on the composite electrode when the content of TiO2 is higher.     

Copper Oxide – Graphite Composite Electrodes: Application to Nitrite Sensing

A simple method for the modification of carbon powder with copper oxides is presented. Carbon powder is impregnated with copper(II) nitrate by stirring carbon powder in copper(II) nitrate solution for 1 hour and subsequently thermally treated at 823 K. The modified carbon powder was characterized using electrochemical and spectroscopic techniques. The existence of both copper(I) and copper(II) oxides have been established. The copper oxide modified carbon powder was used for preparation of composite electrodes, and the electrochemical and electrocatalytic behavior of the resulting composite electrodes was studied. The copper oxide modified carbon powder – epoxy composite electrodes showed a high electrocatalytic activity for the nitrite detection in aqueous media, with the detection limit comparable or lower than detection limits obtained with other electrochemical sensors.     

Green synthesis of graphene nanosheets/ZnO composites and electrochemical properties

A green and facile approach was demonstrated to prepare graphene nanosheets/ZnO (GNS/ZnO) composites for supercapacitor materials. Glucose, as a reducing agent, and exfoliated graphite oxide (GO), as precursor, were used to synthesize GNS, then ZnO directly grew onto conducting graphene nanosheets as electrode materials. The small ZnO particles successfully anchored onto graphene sheets as spacers to keep the neighboring sheets separate. The electrochemical performances of these electrodes were analyzed by cyclic voltammetry, electrochemical impedance spectrometry and chronopotentiometry. Results showed that the GNS/ZnO composites displayed superior capacitive performance with large capacitance (62.2 F/g), excellent cyclic performance, and maximum power density (8.1 kW/kg) as compared with pure graphene electrodes. Our investigation highlight the importance of anchoring of small ZnO particles on graphene sheets for maximum utilization of electrochemically active ZnO and graphene for energy storage application in supercapacitors.