煤基石墨烯/炭纳米纤维复合材料的制备及其电化学性能

Preparation and electrochemical performance of carbon nanofiber/coal based graphene composites

作为一种高性能新型储能器件,超级电容器具有功率密度高、充电时间短、绿色环保等诸多优点,决定超级电容器性能的关键因素是电极材料的性能。以煤为原料,通过高温热处理、化学氧化及等离子体还原技术制备得到煤基石墨烯;进一步将煤基石墨烯与聚丙烯腈(PAN)通过静电纺丝技术复合制备得到煤基石墨烯/炭纳米纤维(PM-CG)复合材料,以期借助于石墨烯所具备的高导电性、电子迁移率等性能获得具有优良电化学性能的电极材料。采用物理吸附仪、扫描电镜以及透射电镜等仪器对所制备的炭纳米纤维进行了表征,并通过电化学工作站研究了其作为超级电容器电极材料的电化学性能。结果表明,煤基石墨烯成功掺杂到炭纳米纤维中,所制备的PM-CG复合材料在6 mol/L KOH电解液中的比电容值可达225.1 F·g^(-1),是同样条件下纯PAN炭纳米纤维比电容值的2.57倍。

As a novel energy storage device with high performance, supercapacitors have lots of excellent properties including high power density, short charging time and environmental friendliness, etc. The electrode materials were considered as the key factor for the performances of supercapacitor. The coal based graphene was prepared by high temperature treatment combined with chemical oxidation and plasma technology with a coal as the raw material. With the aid of high conductivity, electron mobility and other prop- erties of graphene, the carbon nanofibers/graphene composites （PM-CG） were obtained by using graphene and polyacrylonitrile（PAN） as precursors through the electrospinning method. Then PM-CG was characterized by physical adsorption analysis, SEM and TEM measurements. The results showed that the coal based graphene has been doped into carbon nanofiber. The as-made PM-CG com- posites exhibit good capacitive behavior with a high specific capacitance of 225.1 F·g^-1 at a current density of 1 A·g^-1 in 6 mol/L KOH electrolyte, which is 2.57 times higher than that of the pristine carbon nanofibers.