聚苯胺纳米纤维@还原氧化石墨烯纳米卷复合材料的制备及其在超级电容器中的应用

Preparation of polyaniline nanofiber@reduced graphene oxide nanoscroll composite and its application in supercapacitors

针对聚苯胺作为赝电容超级电容器电极材料时存在循环稳定性差的问题,设计利用还原氧化石墨烯纳米卷包裹聚苯胺纳米纤维.采用高沸点有机溶剂辅助冷冻干燥法制备了聚苯胺纳米纤维@还原氧化石墨烯纳米卷复合材料,利用扫描电子显微镜、透射电子显微镜、能谱分析仪、傅里叶变换红外光谱以及X-射线衍射等对该复合材料的形貌、组成和结构进行表征,并采用循环伏安、恒流充放电、电化学阻抗等方法对其电容性能进行研究.结果表明,利用高沸点有机溶剂辅助冷冻干燥法能够成功将聚苯胺纳米纤维包裹进氧化石墨烯纳米卷中,最终将氧化石墨烯还原后得到聚苯胺纳米纤维@还原氧化石墨烯纳米卷复合材料;该复合材料经过5000次循环充放电后电容量保持率达到75%;当复合材料中的聚苯胺纳米纤维质量分数为67%时,该复合材料在2.2 A/g的电流密度下,质量比电容达到639 F/g,表现出优异的电容性能.

In order to improve the cycling stability of polyaniline as pseudocapacitance electrode material,we design a new material that utilizes reduced graphene oxide nanoscroll to encapsulate polyaniline nanofiber.The polyaniline nanofiber@reduced graphene oxide nanoscroll composite are prepared using an organic solvent-assisted lyophilization method.The morphology,composition,and structure of polyaniline nanofiber@reduced graphene oxide nanoscroll composite are characterized using scanning electron microscopy,transmission electron microscopy,energy dispersive spectroscopy,Fourier transform infrared spectroscopy,and X-ray diffraction.Cyclic voltammetry,galvanostatic charge/discharge,and electrochemical impedance spectroscopy are used to investigate the supercapacitance performance of polyaniline nanofiber@reduced graphene oxide nanoscroll composite.The results show that the organic solvent-assisted lyophilization method can successfully encapsulate polyaniline nanofiber into the graphene oxide nanoscroll,and polyaniline nanofiber@reduced graphene oxide nanoscroll composite materials are obtained after graphene oxide is reduced.The capacitance retention of the composite material with nanoscroll structure reaches 75%after 5000 cycles of charge and discharge.When the content of polyaniline nanofiber in the composite is 67%,the composite has a specific capacitance of 639 F/g at a current density of 2.2 A/g,indicating excellent supercapacitance performance.