Nabil Karim, Abdelmonem Nabil, Masanobu Nogami, Ismail Ibrahim
Zewail City of Science and Technology, Giza 12578, Egypt.
Chemical Engineering Department, Cairo University, Giza 12613, Egypt.
Materials (Basel). 2020 Feb 1;13(3):655. doi: 10.3390/ma13030655.
In this work a composite monolith was prepared from widely available and cost effective raw materials, textile-grade polyacrylonitrile (PAN) fibers and phenolic resin. Two activation procedures (physical and chemical) were used to increase the surface area of the produced carbon electrode. Characterization of the thermally stabilized fibers produced was made using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and Carbon-Hydrogen-Nitrogen(CHN) elemental analysis, in order to choose the optimum conditions of producing the stabilized fibers. Characterization of the produced composite monolith electrode was performed using physical adsorption of nitrogen at 77 °K, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrical resistivity in order to evaluate its performance. All the electrodes prepared had a mixture of micropores and mesopores. Pressing the green monolith during the curing process was found to reduce largely the specific surface area and to some degree the electrical resistivity of the chemically activated composite electrode. Physical activation was more suitable than chemical activation, where it resulted in an electrode with specific capacity 29 F/g, good capacitive behavior and the stability of the electrical resistivity over the temperature range -130 to 80 °C. Chemical activation resulted in a very poor electrode with resistive rather than capacitive properties.
在这项工作中，由广泛可得且成本效益高的原材料——纺织级聚丙烯腈（PAN）纤维和酚醛树脂制备了一种复合整体材料。采用两种活化程序（物理和化学）来增加所制备碳电极的表面积。使用差示扫描量热法（DSC）、热重分析（TGA）和碳 - 氢 - 氮（CHN）元素分析对所制备的热稳定纤维进行表征，以便选择生产稳定纤维的最佳条件。使用77 K下氮气的物理吸附、循环伏安法（CV）、恒电流充放电（GCD）和电阻率对所制备的复合整体电极进行表征，以评估其性能。所有制备的电极都具有微孔和中孔的混合物。发现在固化过程中对生坯整体材料进行压制会大大降低比表面积，并在一定程度上降低化学活化复合电极 的电阻率。物理活化比化学活化更合适，物理活化得到的电极比电容为29 F/g，具有良好的电容行为，并且在-130至80°C的温度范围内电阻率稳定。化学活化得到的电极性能很差，具有电阻特性而非电容特性。
