高性能超级电容器用高载量N掺杂层状多孔炭电极

在保持快速充/放电特性的同时,提高超级电容器的能量密度将极大地扩展其应用领域.本文以野生箩藦壳为碳源、ZnCl2为活化剂、NH4Cl)为氮源,通过一步法制备了氮掺杂层状多孔炭(NPCM)作为高性能超级电容器电极材料.该NPCM材料具有高的电导率、较高的离子可接触比表面积和快速的离子传输通道,显示出高质量比容量(457 ...     

活性泡沫炭用于超级电容器电极材料

以酚醛树脂、煤沥青泡沫炭为原料,经水蒸气活化制得比表面积分别为961和953m2/g的活性泡沫炭。采用扫描电镜、BET吸附仪、恒流充放电法和循环伏安法对两种活性泡沫炭的结构进行了表征并研究其充放电性能。结果表明,酚醛树脂泡沫炭在1.0nm以下的孔较煤沥青泡沫炭丰富。在1.0mA充放电时,两者的充放电容量分别为106.28和105.1F/g,相差不大,当充放电电流增大到50mA时,前者容量为41.94F/g,后者为17.23F/g。可见,微孔的孔径分布对充放电性能具有很大影响,增大微孔的孔径有利于提高活性炭电极的充放电容量和功率。循环伏安法测试表明在100mV/min扫描速率下酚醛树脂泡沫炭粉的电化学窗口大于煤沥青泡沫炭粉。     

超级电容器电极用N-掺杂多孔碳材料的研究进展

多孔碳材料作为双电层电容器的主要电极材料,已成功应用于商业化超级电容器。但作为电极材料,纯碳材料表面疏水、内阻较大、电容较低等缺点使其进一步发展受到制约。近年来,随着超级电容器的迅速发展,氮掺杂多孔碳材料作为其电极材料引起研究人员的广泛关注,并采用不同的制备方法成功合成了一系列结构不同、性能优异的氮掺杂碳材料。基于超级电容器氮掺杂多孔碳电极材料的最新研究进展,首先介绍了氮在碳材料中的基本存在形式及对碳电极材料性能的影响,然后重点评述了氮掺杂碳电极材料的制备,最后总结了超级电容器氮掺杂碳材料的发展趋势。     

超级电容器用中孔炭的研究

以石油焦为原料,运用化学活化法制备了超级电容器用高比表面积中孔活性炭。利用XRD、SEM和BET对实验制备的中孔炭进行了分析和表征。以实验制备的活性炭为超级电容器电极材料,利用恒流充放电测试对其电容特性进行了研究。结果表明,实验研制的活性炭的比表面积为1733m^2／g,中孔含量达到60．6％,在150mA／g的电流密度下其比容达到180F／g,而且基于实验研制的活性炭的超级电容器具有低内阻和良好的功率特性。     

多孔炭对超级电容器电荷存储的影响

由于具有良好的物理化学稳定性、高比表面积、可调的孔结构及优良的导电性,多孔炭广泛应用于超级电容器电极材料.它的电容性能与其比表面积、孔结构、表面杂原子、结构缺陷及电极结构密切相关.离子及表面积(有效表面)能够提供丰富的活性位点,而合适的孔结构有利于离子的传输和存储,因而共同影响着炭基电极材料的比电容和倍率性能.具有合适...     

超级电容器用含氮多孔炭电极材料的研究进展

概述了表面改性和本体富氮两种负载氮原子的方法及其优缺点,总结了经高温处理后炭材料表面含氮官能团(N-6、N-5、N-Q、N-X)的转化机制:氮原子最终以化学性质稳定的六圆环的形式出现(如N-6、N-Q、N-X),温度高于600℃时,N-5(Pyrrolic-N)通过扩环作用转变为N-6、N-Q、N-X。最后从法拉第氧化还原反应(产生赝电容)和电极的湿润性两方面归纳了表面含氮官能团对超级电容器电化学性能的影响,并展望了今后的研究方向。     

有序介孔炭材料表面电活性氧基团的构造及其超级电容器性能

以酚醛树脂为前体,表面活性剂F127为软模板,通过蒸发诱导自组装法制备了有序介孔聚合物,将其水热负载氢氧化镁并在高温下进行碳化得到具有有序介孔结构和丰富活性氧基团的有序介孔炭材料。系统研究了水热浸渍温度对所得材料表面积、孔体积及超级电容器性能的影响。结果表明:随着温度的升高,氢氧化镁负载量升高,但其表面积下降,最佳的水热浸渍温度为150℃,在该温度下水热浸渍的氢氧化镁的负载质量为3.3%,所得材料的表面积为326m~2/g,其作为电极用于超级电容器的容量为212F/g。     

自生模板法制备多孔炭材料及其超级电容器性能

以柠檬酸锌为前体,利用碳化过程中产生的ZnO作为模板,制备了具有高比表面积和丰富孔道结构的多孔炭材料,系统研究了碳化温度对所得材料比表面积、孔体积及超级电容器性能的影响。结果表明:随着温度的升高,比表面积增大,孔容增大,多孔炭材料的电容性能也相应提高,在碳化温度为1273K时,所得炭材料(Zn C1273)的比表面积高达1763m2/g,孔容为3. 08cm3/g。利用1. 0mol/L四乙基四氟硼酸铵的乙腈溶液为电解质,所得炭材料作为电极应用于超级电容器,在0. 5～20A/g高电流密度下的容量保持率为93. 2%。     

超级电容器电极材料

本文综述了碳基材料、金属氧化物及水合物材料和导电聚合物材料作为超级电容器电极材料的最新研究进展。     

超级电容器用生物质基多孔炭的研究进展

在最近的几十年中,超级电容器(SC)已在电化学能量存储设备中获得了更为重要的地位.SC为使用寿命长的能量存储设备提供了可观的功率密度和令人满意的能量密度,适用于多种应用.因此,这些装置的进一步发展依赖于提供合适,低成本,环境友好和丰富的材料作为SC的电极活性材料.在用于SC的电极材料中,活性炭表现出优异的性能.它们具有...     

On the use of mesophase pitch for the preparation of hierarchical porous carbon monoliths by nanocasting

Abstract

A detailed study is given on the synthesis of a hierarchical porous carbon, possessing both meso- and macropores, using a mesophase pitch (MP) as the carbon precursor. This carbon material is prepared by the nanocasting approach involving the replication of a porous silica monolith (hard templating). While this carbon material has already been tested in energy storage applications, various detailed aspects of its formation and structure are addressed in this study. Scanning electron microscopy (SEM), Hg porosimetry and N₂ physisorption are used to characterize the morphology and porosity of the carbon replica. A novel approach for the detailed analysis of wide-angle x-ray scattering (WAXS) from non-graphitic carbons is applied to quantitatively compare the graphene microstructures of carbons prepared using MP and furfuryl alcohol (FA). This WAXS analysis underlines the importance of the carbon precursor in the synthesis of templated porous carbon materials via the nanocasting route. Our study demonstrates that a mesophase pitch is a superior precursor whenever a high-purity, low-micropore-content and well-developed graphene structure is desired.     

含氮多孔炭的制备及其在二氧化碳吸附中的应用

以甲醛(F)和间苯二酚(R)为炭源,赖氨酸为催化剂,采用快速溶胶凝胶法所制含氮多孔炭(RFL)对CO2具有较高的吸附能力;为增加RFL的氮含量,引入适量的三聚氰胺(M),制得的多孔炭(RFLM)含N量增加,比表面积和孔体积也有所增加;在合成体系中进一步引入谷氨酸(G),可使聚合反应速率得到控制,且多孔炭(RFLMG)的织构性质也得到进一步优化。RFLM和RFLMG对CO2的吸附能力较RFL弱,说明多孔炭的含N量与其对CO2的吸附能力没有明确的线性关系,而含氮官能团的存在形式会影响多孔炭对CO2的吸附能力。     

Graphene-based carbon nano-fibers grown on thin-sheet sinter-locked Ni-fiber as self-supported electrodes for supercapacitors

A promising thin-sheet graphene-based carbon/Ni-fiber hybrid structure has been developed by the catalytic chemical vapor deposition of ethanol on a sinter-locked 3-dimensional network consisting of 5 vol.% 8-μm-nickel fibers. It is revealed that the graphene nano-sheets consisting of tens of graphene single-layers are stacked in one line to form mesopore-rich carbon nano-fibers (CNFs). One of the most promising is its use as electrodes in electrochemical devices. When employed in an electrochemical capacitor, this hybrid shows excellent capacitive behavior and delivers pleasing specific capacitance at high current density (e.g., 87-100 F/g @ 100-500 mA/g).     

纳米结构的炭钌复合物-一种提高超级电容器性能的电极材料

报道了一种利用氧化硅模板,裂解简单易得的含钌有机物制备纳米结构炭/钌复合物的方法.在该复合物中,钌纳米颗粒均匀地分布在多孔的炭基体中.该复合物被电氧化所得炭/RuO2·xH2O的超级电容性质明显提高(10 mV/s 时229 F/g ).     

Nitrogen-doped hierarchical porous carbon materials derived from diethylenetriaminepentaacetic acid (DTPA) for supercapacitors

Nitrogen-doped porous carbon materials (NPCs) have been successfully fabricated by a simple one-step pyrolysis of diethylenetriaminepentaacetic acid (DTPA) in the presence of KOH. The as-synthesized NPCs displayed a high specific surface area (3214?m²?g^?1) and a well-defined porous structure when the annealing temperature reached 800?°C, which showed superior electrochemical performance as supercapacitor electrode materials. Electrochemical tests showed that the NPCs achieved an impressive specific capacitance of 323?F?g^?1 at a current density of 0.5?A?g^?1 in 6?M KOH aqueous solution and an outstanding cycle stability, negligible specific capacitance decay after 5000 cycles at 10?A?g^?1. This strategy offered a new insight into the preparation of novel carbon materials for the advanced energy storage devices, such as supercapacitors, fuel cells and lithium ion batteries.     

Modified nano-CaCO3 hard template method for hierarchical porous carbon powder with enhanced electrochemical performance in lithium-sulfur battery

Lithium-sulfur (Li-S) battery was the most promising energy storage devices with ultrahigh energy density (2600 Wh kg⁻¹). But it was impeded by poor electronic conductivity, serious shuttle effect, and enormous volume expansion. Herein, hierarchical porous carbons were simply prepared by a modified nano-CaCO₃ hard-template method from glucose. The template-removal step was modified from HCl washing to HCl soaking. This allowed the microstructure of carbon product significantly involved. Furthermore, the mass ratio of CaCO₃ nanoparticles and glucose played an important role in booming of hierarchical porous and specific surface area. When integrated with S, functioned as cathode in Li-S battery, improved electrochemical performances were exhibited, such as high initial discharge capacity and good capacity retention. This modified hard-template method suggested a promising way to fabricate hierarchical porous carbon matrix available to apply in advanced Li-S battery.     

Flower-like hierarchical porous nitrogen-doped carbon spheres from a facile one-step carbonization method for supercapacitors

A facile one-step carbonization method was developed to fabricate flower-like hierarchical porous nitrogen-doped carbon sphere (FHPNCS) from polyimide using polyurethane foam as macroporous scaffold. The FHPNCS possessed flower-like spherical morphology, well-developed hierarchical porous structure, high specific surface area and nitrogen-containing functional groups. These advantages led to excellent electrochemical performance. The FHPNCS electrode exhibited a high specific capacitance of 251.6 F g^?1 at 1 A g^?1, a high rate capability of 76% capacitance retention at 5 A g^?1, and an outstanding cycling stability of only 4.4% loss in specific capacitance after 2000 cycles. Compared with previously reported multi-step templating methods, the present method only involves a facile thermal treatment procedure and avoids the use of hard templates and toxic raw materials, thus exhibiting great potential for large scale production of nitrogen-doped carbon materials for practical applications in supercapacitors.     

Hierarchically porous carbon derived from renewable Chingma Abutilon Seeds for high-energy supercapacitors

The cost-effectively biomass-derived porous carbon is highly promising for usage in electrochemical energy storage as the electrode materials. Herein, a series of hierarchically porous carbons with biomass Chingma Abutilon Seeds as the renewable precursor were synthesized via KOH activation and high-temperature carbonization technique. The resulting carbon material possessed an interconnected structure, high specific surface area (120–3566 m² g^?1), hierarchical pores as well as the heteroatom-substituted functional groups. Based on the synergistic effect of the above-mentioned merits, the optimized material exhibited the remarkably electrochemical performance with high specific capacitance (389 F g^?1 at 0.5 A g^?1) and excellent rate stability (72% capacitance retention at 20 A g^?1) in the three-electrode configuration. More significantly, the symmetric two-electrode device assembled in 6 M KOH delivered a high energy density of 39.2 Wh kg^?1 and excellent chemical stability (90% capacitance retention after 10,000 cycles at 5 A g^?1). Such prominent results might provide a new perspective on the value-added application of the renewable biomass resources in the electrochemical field.     

Bismuth oxide/nitrogen-doped carbon dots hollow and porous hierarchitectures for high-performance asymmetric supercapacitors

The development of high-performance anode materials is critical for next-generation asymmetric supercapacitor devices. Herein, an advanced anode of bismuth oxide/nitrogen-doped carbon dots (Bi₂O₃/NCDs) hollow and porous hierarchitecture was successfully developed by a facile two-step strategy. It is revealed that the presence of NCDs can not only induce the assembly of Bi₂O₃ porous nanosheets to hollow microspheres, but also remarkably improve the specific capacitances of them. Attributing to the intriguing properties of NCDs and the unique structure of Bi₂O₃/NCDs composites, the Bi₂O₃/NCDs hierarchitectures deliver an enhanced specific capacitance of approximately 1046 F g⁻¹ at a current density of 1 A g⁻¹. In particularly, an asymmetric supercapacitor was constructed by using the Bi₂O₃/NCDs hierarchical microspheres as anode and Ni(OH)₂/NCDs nanosheets as cathode, which exhibits an ultrahigh energy density of about 79.9 Wh kg⁻¹ at 770.9 W kg⁻¹. These results indicate that the Bi₂O₃/NCDs hollow and porous hierarchitectures hold great potential as novel anode materials for energy storage.     

Mn2O3/carbon aerogel microbead composites synthesized by in situ coating method for supercapacitors

A series of Mn₂O₃/carbon aerogel microbead (Mn₂O₃/CAMB) composites for supercapacitor electrodes have been synthesized by in situ encapsulation method. The structure and morphology of Mn₂O₃/CAMB are characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectrum and scanning electron microscopy (SEM). Electrochemical performances of the synthesized composites are evaluated by cyclic voltammetry and galvanostatic charge/discharge measurement. All the composites with different Mn₂O₃ contents show higher specific capacitance than pure CAMB due to the pseudo-capacitance of the Mn₂O₃ particles dispersed on the surface of CAMB. The highest specific capacitance is up to 368.01 F g⁻¹ when 10 wt% Mn₂O₃ is coated on the surface of CAMB. Besides, 10%-Mn₂O₃/CAMB supercapacitor exhibits excellent cyclic stability, the specific capacitance still retains 90% of initial capacitance over 5000 cycles.