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1.
中孔活性炭电极储电影响因素研究   总被引:2,自引:1,他引:1  
选用树脂基中孔活性炭作为双电层电容器的电极材料 ,通过水蒸气活化提高活性炭的比表面积 .实验发现 ,随着活化时间的延长 ,活性炭收率降低 ,活化 2 h烧失率高达 73.5 % ,比表面积从原来的 761 m2 g增加到 1 480 m2 g.孔结构分析表明 ,随活化时间的延长 ,在 2 nm附近孔容分布强度增强 .活性炭电极的放电时间和比电容随活化时间的延长而增加 ,但增速变缓 ,活化 2 h活性炭的比电容最高为 1 85 .84F/ g,增加了 2 8.9% .  相似文献   

2.
以无灰煤(HPC)为原料,KOH为活化剂,采用直接活化法制备无灰煤基活性炭(HAC),并在不同活化温度下探究HAC孔结构的衍化规律。结果表明:活化温度较低时,活化过程表现为无规则碳的烧失,同时微晶单元参与反应,片层明显减小,主要形成0.5 nm以下的微孔,以开孔作用为主。随活化温度的升高,KOH刻蚀微晶结构加剧,以扩孔作用为主,孔径大于0.5 nm的孔居多,同时发展超微孔和中孔。将HAC作为电极材料应用于水系双电层电容器(EDLC)时,其显示出优异的电化学性能,在电流密度为50 mA/g时的比电容达258.2 F/g,在电流密度为5000 mA/g时的比电容保持率在80%以上。研究还发现,EDLC的比电容随HAC电极中0.5 nm^1.5 nm微孔的增加而增大。  相似文献   

3.
    
Cellulose has a wide range of applications in many fields due to their naturally degradable and low-cost characteristics, but few studies can achieve cellulose-nanofibers by conventional electrospinning. Herein, we demonstrate that the freestanding cellulose-based carbon nanofibers are successfully obtained by a special design of electrospinning firstly, pre-oxidation and high-temperature carbonization (1600 °C), which display a superior electrical conductivity of 31.2 S·cm–1 and larger specific surface area of 35.61 m2·g–1 than that of the polyacrylonitrile-based carbon nanofibers (electrical conductivity of 18.5 S·cm–1, specific surface area of 12 m2·g–1). The NiCo2O4 nanoflake arrays are grown uniformly on the cellulose-based carbon nanofibers successfully by a facile one-step solvothermal and calcination method. The as-prepared cellulose-based carbon nanofibers/NiCo2O4 nanoflake arrays are directly used as electrodes to achieve a high specific capacitance of 1010 F·g–1 at 1 A·g–1 and a good cycling stability with 90.84% capacitance retention after 3000 times at 10 A·g–1. Furthermore, the all-solid-state symmetric supercapacitors assembled from the cellulose-based carbon nanofibers/NiCo2O4 deliver a high energy density of 62 W·h·kg–1 at a power density of 1200 W·kg–1. Six all-solid-state symmetric supercapacitors in series can also power a ‘DHU’ logo consisted of 36 light emitting diodes, confirming that the cellulose-based carbon nanofiber is a promising carbon matrix material for energy storage devices.  相似文献   

4.
活性炭纤维制备双电层电容器   总被引:6,自引:2,他引:6  
研究了不同材料、比表面积和电解液对比电容的影响,不同比表面积,电解液对循环充电稳定性的影响。结果表明,作为制备双电层电容器的电极材料,活性炭纤维明显好于活性炭,同样基质的活性炭纤维,比表面积大的,比电容不一定大。  相似文献   

5.
陈再华  王正郁 《炭素》2010,(1):18-23
以酚醛树脂(PF)为原料,利用氢氧化钾(KOH)活化法制备900m^2/g~2300m^2/g的活性炭,明确了活性炭的比表面积与堆比重、总孔容等的关系。以该系列的活性炭作为电极材料,通过水溶液系(40%的H2SO4水溶液)和有机溶液系(电解液:1MEt4NBF4/PC溶液)双电接电容器的充放电实验,论述了EDLC对活性炭性能的要求。结果表明,用于水系的活性炭的最适比表面积为1000m^2/g左右,用于有机系的最适比表面积为2000m^2/g左右。  相似文献   

6.
李兵红  梁逵  庄凯  胡军 《炭素》2006,(1):32-35
以煤为原料,KOH为活化荆,采用微波加热法制备出双电层电容器用活性炭。研究了KOH与煤比例:微波功率和辐射时间对活性炭比电容量的影响,并考察了煤基活性炭双电层电容器的充放电特性。结果表明:在KOH与煤比例为3:1、微波功率为640瓦和辐射时间为7分钟时,制备出的活性炭比电容量迭286.28F/g,而且稳定性很好。  相似文献   

7.
Activated carbon fiber cloth (ACFC) electrodes with high double layer capacitance and good rate capability were prepared from polyacrylonitrile (PAN) fabrics by optimizing the carbonization temperature prior to CO2 activation. The carbonization temperature has a marked effect on both the pore structure and the electrochemical performances of the ACFCs. Moderate carbonization at 600 °C results in higher specific surface area and larger pore size, and hence higher capacitance and better rate capability. The specific capacitance of the ACFCs in 6 mol L−1 KOH aqueous solution can be as high as 208 F g−1. It remains 129 F g−1 as the current density increases to 10 000 mA g−1.  相似文献   

8.
陈再华 《炭素》2009,(4):3-8
以回收聚酯(PET)为原料,通过微波的内部和外部的混合加热,结合氢氧化钾(KOH)活化法制备高纯度、高比表面积活性炭,介绍了制备方法和炭化、活化工艺条件。采用这种方法可制得比表面积在3200m^2/g以上、最频孔径在1~3nm的活性炭。通过电镜等结果,从构造观点阐明了活性炭的比表面积、细孔结构等性质,通过氢气还原处理,可降低活性炭的表面含氧官能团浓度。该活性炭作为有机溶液系(电解液:1MEt4NBF4/PC溶液)双电层电容器的电极材料,具有48F/g以上的比电容量。  相似文献   

9.
碳(炭)材料与超级电容器   总被引:4,自引:0,他引:4  
多孔碳(炭)材料是用来制造超级电容器电极的理想材料之一.特别是中孔(≥nm)丰富的多孔碳(炭)材料,最适合制造超级电容器的电极.  相似文献   

10.
Electrochemical parameters of the nanoporous carbide-derived carbon|organic electrolyte have been studied by cyclic voltammetry and electrochemical impedance spectroscopy. The gas adsorption measurements have been used for evaluating the specific surface area, pore size distribution and porosity as the essential parameters influencing the double layer performance of carbon. The region of ideal polarizability, values of series and parallel resistance, capacitance and other important electrical double layer parameters were established. It was shown that specific capacitance of typical nanoporous carbon derived from titanium carbide is in the range of 70-90 F cm−3 or 100-130 F g−1 and it depends on the synthesis conditions. The influence of the electrolyte solvent to the capacitance was insignificant, although acetonitrile was advantageous with respect of smaller viscosity.  相似文献   

11.
采用共沉降法制备了以Ni为载体的NiCo2O4/Ni的电催化剂,分别用TG、XRD、SEM对NiCo2O4粉末的结构和形貌进行了表征,研究了不同温度下NiCo2O4/Ni复合电极在碱性水溶液中的催化性能.结果表明,热处理温度对NiCo2O4粉末的结构、电催化性能有重要的影响,当热处理温度为300%时NiCo2O4/Ni...  相似文献   

12.
Increasing number of CNG vehicles on road emits considerable amount of CO, a poisonous gas and CH4, a greenhouse‐gas. Highly active and oxygen‐deficient NiCo2O4‐δ spinel and its individual metal‐oxides were synthesized by calcination of precipitated/co‐precipitated basic‐carbonates followed by calcination under different strategies of stagnant air(s), flowing air(f) and reactive calcination(RC) for total oxidation of CO‐CH4 mixture. The catalysts were characterized by XRD, XPS, BET surface‐area, SEM‐EDX and TEM. The performance order of the catalysts for the oxidation of CO‐CH4 mixture was as follows: NiCoRC>NiCof>NiCos>CoRC>Cof>Cos>NiRC> Nif>Nis. The pairing of Ni and Co in spinel‐structure together with RC produced catalyst was oxygen‐deficient highly active for total oxidation of the mixture at the lowest temperature of 350°C. The NiCoRC was found stable under reaction‐conditions for 50h at 350°C and after four successive heating (350°C)‐cooling (35°C) cycles besides accelerated‐aging tests up to 600°C. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2632–2646, 2018  相似文献   

13.
竹炭基高比表面积活性炭电极材料的研究   总被引:19,自引:0,他引:19  
以竹节为原料,在隔绝空气的条件下,经不同温度炭化处理后与KOH混合,制取竹炭基高比表面积活性炭。考察了炭化温度、KOH与竹炭的质量比、活化温度和活化时间等工艺因素对活性炭收率、微孔结构和吸附性能的影响,探讨了竹炭基高比表面积活性炭作双电层电容器电极时的充放电特性及其比电容与各种因素的关系。研究结果表明,控制适宜的炭化、活化工艺条件可制得双电极比电容达55F/g的竹炭基高比表面积活性炭,由它组装的双电层电容器具有良好的充放电性能和循环性能,但内阻过高,大电流下充放电时电容量下降过大。  相似文献   

14.
酚醛树脂基活性炭的制备及双电层电容特性   总被引:1,自引:0,他引:1  
以热固性酚醛树脂为原料,采用CO2物理活化法制备双电层电容器用高比表面积活性炭。由氮气吸附法测定活性炭的比表面积和孔结构,采用循环伏安、交流阻抗和恒电流充放电考察其在30%KOH水溶液中的电容特性。结果表明,随着活化温度的升高,所得活性炭收率下降,比表面积、总孔孔容和质量比电容不断增加;具有高比表面积和宽孔径分布的试样APF953,具有最高的质量比电容值,电流密度由50mA·g^-1提高到500mA·g^-1时,其放电比电容由183.36F·g^-1降低到175.68F·g^-1,容量保持率达到96%,显示出良好的电容特性。  相似文献   

15.
串联碳纳米管双电层电容器电容特性的研究   总被引:6,自引:1,他引:5  
研究了在38%的硫酸电解液中加入电压调节剂HBr后碳纳米管单元电容器和串联电容器容量和漏电流的变化,以及电压调节剂在串联器中平衡分压的作用。  相似文献   

16.
Increasing the available cell voltage for electrochemical double layer capacitors (EDLC) is one route to simultaneously increase energy density and power density of the EDLC. Increased cell voltage may, however, introduce faradaic reactions such as ion insertion and electrolyte decomposition, which potentially limit the lifetime of the device. Using a purpose designed pressure cell, we have, for the first time, measured the pressure increase in capacitor cells based on real EDLC electrode coils in 1 M (C2H5)4NBF4/propylene carbonate electrolyte during cycling between 0 and 2.5 V and for constant cell voltages up to 3 V. During cycling a reversible pressure decrease was observed upon charging. An irreversible pressure increase was monitored during load tests at constant cell voltages above 2.5 V. The absolute amount of gases evolved could be determined by means of simultaneous compressibility monitoring.  相似文献   

17.
Porous carbons with high-volumetric capacitance in aqueous electric double layer capacitors (EDLCs) were simply prepared by poly(vinylidene chloride) (PVDC) carbonization at high temperature without activation or any other additional processes. The PVDC-derived carbon is microporous with Brunauer-Emmett-Teller (BET) surface area about 1200 m2 g−1. As it possesses not only high-gravimetric capacitance (262 F g−1) but also high-electrode density (0.815 g cm−3), the PVDC-derived carbon present an outstanding high-volumetric capacitance of 214 F cm−3, twice over of the commercial carbon Maxsorb-3 with a high-surface area of 3200 m2 g−1. The PVDC-derived carbon also exhibit good rate performance, indicating that it is a promising electrode material for EDLCs.  相似文献   

18.
文章介绍了中微双孔活性炭的制备方法,综述了用作双电层电容器的最新应用研究,为中微双孔活性炭在双电层电容器中的应用提供参考。  相似文献   

19.
溶胶凝胶法制备V2O5,采用球磨法将V2O5与石墨进行固相混合,经扫描电镜(SEM)、X射线衍射(XRD)、循环伏安、交流阻抗等测试手段分析,得出石墨可改变V2O5电极的微结构和组成;由20%V2O5/C复合材料和石墨组成的非对称电化学电容器,以1 mol/L LiClO4(EC:DEC=1:1)有机溶液为电解液,比能量可达到18.3 W.h/kg,比纯V2O5提高56.8%,循环400次后复合材料的容量衰减为25.68%,比容量和循环性能较掺杂前得到显著提高。  相似文献   

20.
双电层电容器用多孔炭材料的研究与开发   总被引:4,自引:3,他引:4  
阐述了双电层电容器的工作原理,探讨了多孔炭材料的比表面积、孔径分布、表面官能团、表面石墨微晶取向、体积密度和电导率以及电化学稳定性等微孔结构与物理化学性质对其电容特性的影响,介绍了近年来用作双电层电容器电极的几种新型多孔炭材料的研究进展。  相似文献   

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