螺旋炭纤维的微观结构与储能特性

The microstructure and energy storage characteristics of micro-coiled carbon fibers

采用扫描电镜、激光Raman光谱、X射线衍射(XRD)、热失重分析(TG)、低温氮吸附等研究手段,以平直炭纤维为参照,对比研究了碳氢化合物催化分解法制备的螺旋型炭纤维的微观结构特征。实验结果表明:整体上,螺旋炭纤维的微观结构要比平直炭纤维的结构更加无序;但螺旋炭纤维的外层结构较为有序。与中孔分布广、孔容低的平直炭纤维不同,螺旋炭纤维的中孔主要分布在3nm～4nm范围内,且有着较高的孔容,其比表面积几乎是平直炭纤维的10倍。这些结构特性使得螺旋炭纤维在抗氧化性、储氢、电化学电容等方面都体现出超越平直炭纤维的优势和应用潜力。

The microstructure of micro-coiled carbon fibers synthesized by the catalytic decomposition of acetylene was analyzed using scanning electron microscopy, Raman spectroscopy, X-ray diffraction, thermogravimetry and nitrogen cryo-adsorption and compared with those of straight carbon fibers with a similar diameter. The crystalline sizes of the graphitic domains of the straight carbon fibers are larger than those of the micro-coiled fibers, but the outer layers of the micro-coiled carbon fibers are more ordered than that of the straight carbon fibers. The pore size distribution of straight carbon fibers is broad, while the pore size of the micro-coiled carbon fibers is narrowly distributed between 3 urn and 4 nm. The pore volume of micro-coiled carbon fibers is much higher than that of straight carbon fibers, and its BET surface area is almost ten times as much as that of straight carbon fibers. Results show that the oxidation resistance, hydrogen storage and electrochemical capacitance of the micro-coiled carbon fibers are superior to those of straight carbon fibers.