Electrochemical capacitors based on highly porous carbons prepared by KOH activation
Electrochemical capacitors based on highly porous carbons prepared by KOH activation
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DOI：
10.1016/j.electacta.2003.08.026
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发表时间：
2004-02-15
影响因子：
6.6
通讯作者：
Machnikowski, J
中科院分区：
文献类型：
--
作者：
Kierzek, K;Frackowiak, E;Machnikowski, J
各种煤和沥青衍生的含碳材料在800 ℃下使用氢氧化钾和1：4的组分比活化5小时。通过在77 K下的N-2吸附来评估所得活性炭（AC）的孔隙率发展，并使用恒电流、伏安和阻抗谱技术来确定其在双电层中电荷积累的能力。由不同前体生产的活性炭均具有微孔特征，但总孔体积（1.05至1.61 cm（3）g（-1））、BET表面积（1900至3200 m（2）g（-1））和孔径分布不同。这些材料在酸性1 mol-1 H2SO 4电解质溶液中的电容值范围为200 ~ 320 Fg（-1）。的电化学行为（电荷传播，自放电，频率响应）的变化被认为是有关的多孔纹理特性，元素组成，但也可能影响结构排序由于使用的各种前体材料。还对所有电容器进行了循环研究，以比较不同碳材料在后续循环期间的电荷积累能力。(C)2003 Elsevier Ltd.保留所有权利。
Various coal and pitch-derived carbonaceous materials were activated for 5 h at 800 degreesC using potassium hydroxide and 1:4 component ratio. Porosity development of the resultant activated carbons (ACs) was assessed by N-2 sorption at 77 K and their capability of the charge accumulation in electric double layer was determined using galvanostatic, voltammetric and impedance spectroscopy techniques. ACs produced from different precursors are all microporous in character but differ in terms of the total pore volume (from 1.05 to 1.61 cm(3) g(-1)), BET surface area (from 1900 to 3200 m(2) g(-1)) and pore size distribution. Very promising capacitance values, ranging from 200 to 320 Fg(-1), have been found for these materials operating in acidic 1 mol 1(-1) H2SO4 electrolytic solution. The variations in the electrochemical behavior (charge propagation, self-discharge, frequency response) are considered in relation to the porous texture characteristics, elemental composition but also possible effect of structural ordering due to various precursor materials used. Cycling investigation of all the capacitors has been also performed to compare ability of the charge accumulation for different carbon materials during subsequent cycles. (C) 2003 Elsevier Ltd. All rights reserved.