静电纺丝法制备MnO_x掺杂聚丙烯腈碳纤维及其对超级电容性能的影响

MnO_x doped PAN-based carbon fibers prepared by electrospinning method and their influence on supercapacitance

利用静电纺丝技术制备了不同乙酸锰(Mn Ac2)含量的聚丙烯腈(PAN)基复合纤维(Mn Ac2/PAN),经预氧化和高温碳化后得到Mn Ox/C复合纤维;利用X射线衍射(XRD)、扫描电镜(SEM)和热重分析(TGA)等方法对纤维进行结构表征,并利用循环伏安、恒电流充放电和交流阻抗技术对复合纤维进行了电化学性能测试.结果表明:复合纤维表面相互粘连形成三维枝状结构,这种结构有利于碳纤维之间导电性的提高;掺杂Mn Ox后碳纤维的超级电容性能得到显著提高,其中乙酸锰质量分数为2%和4%的Mn Ac2/PAN纤维碳化后的产物在0.05 A/g时的比容量分别高达186.0 F/g和156.4 F/g,而纯PAN碳纤维的比容量仅为90.0 F/g.

Polyacrylonitrile fibers with various contents of MnAc2 were prepared by electrospinning method. The as-preparedMnAc2/PAN composite fibers were subjected to two stages of thermal treatment,i.e. pre -oxidation and hightemperature carbonization to obtain the MnOx /C composite fibers. The carbon composite fibers were characterizedby the X-ray diffractions （XRD）,scanning electron microsope （SEM）and thermogravimmetric analysis （TGA）,and the electrochemical performance was investigated by using the cyclic voltammetry （CV）,galvanostaticcharge-discharge measurement and electrochemical impedance spectroscopy （EIS）. The results indicate that thesurface of composite fibers are interconnected forming a branched 3D network,which is good for enhancedconductivity;the supercapacitance of the carbon fibers is significantly improved by the doping of MnOx. Forinstance,the specific capacitances of the fibers obtained from MnAc2 （2% and 4%）/PAN are 186.0 and 156.4 F/gat 0.05 A/g,respectively,while that of pure PAN carbon fiber is only 90.0 F/g.