Free standing hollow carbon nanofiber mats for supercapacitor electrodes
Free standing hollow carbon nanofiber mats for supercapacitor electrodes
复制标题
DOI：
10.1039/c6ra17014e
复制
发表时间：
2016-08
期刊：
影响因子：
3.9
通讯作者：
Shilpa;Ashutosh Sharma
中科院分区：
文献类型：
--
作者：
Shilpa;Ashutosh Sharma
通过同轴静电纺丝和高温热解制备了高石墨含量的自支撑中空碳纤维（CNF）毡。以不同重量比的聚丙烯腈（PAN）和聚（甲基丙烯酸甲酯）（PMMA）的共混物用作壳聚合物，而PMMA用作核聚合物。在碳化过程中去除牺牲PMMA模板，从而在壳中形成沿着具有孔的中空芯。为了建立最佳的基础情况电极，不采用进一步的化学或物理活化程序或添加金属氧化物颗粒。系统研究了中空碳纳米纤维作为超级电容器电极的结构和电化学性能，并与多孔碳纳米纤维（PAN：PMMA重量比为2：1，1：1，1：2，1：5）和实心碳纳米纤维进行了比较。由于其良好的导电性和机械稳定性，该导电毡已被直接用作电极而不需要粘合剂和导电添加剂。壳中前体聚合物比例为1：5（PAN：PMMA）的中空CNF表现出最高的比表面积812.6 m2 g-1，具有大百分比的中孔，在5 mV s-1下提供10185 F g-1的电容，这几乎比固体CNF（1.2 F g-1）高两个数量级。此外，中空CNF表现出优异的充/放电能力，在2A g-1的电流密度下提供105 F g-1的电容，在3000次循环后电容保持率为1080%。这项研究建立了电纺中空CNFs作为潜在的超级电容器电极，可以很容易地通过添加功能材料进一步修饰。
Free standing hollow carbon nanofiber (CNF) mats with high graphitic content have been fabricated through co-axial electrospinning followed by high temperature pyrolysis. A blend of polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) in different weight ratios is used as the shell polymer whereas PMMA is used as the core polymer. The sacrificial PMMA template is removed during carbonization, creating a hollow core along with pores in the shell. In order to establish the best base case electrode, no further chemical or physical activation procedures or addition of metal oxide particles were employed. The structural and electrochemical properties of hollow CNFs as supercapacitor electrodes are systematically studied and compared with those of porous (PAN : PMMA weight ratios 2 : 1, 1 : 1, 1 : 2, 1 : 5) and solid CNFs. The nanofiber mats have been used directly as electrodes without binder and conductive additives owing to their good conductivity and mechanical stability. The hollow CNFs with the precursor polymer ratio of 1 : 5 (PAN : PMMA) in the shell, exhibited the highest specific surface area of 812.6 m2 g−1 with a large percentage of mesopores, delivering a capacitance of ∼185 F g−1 at 5 mV s−1, which was almost two orders of magnitude higher than the solid CNFs (1.2 F g−1). In addition, the hollow CNFs exhibited an excellent charge/discharge capability delivering a capacitance of ∼105 F g−1 at a current density of 2 A g−1, with a capacitance retention of ∼80% after 3000 cycles. This study establishes the electrospun hollow CNFs as potential supercapacitor electrodes that can be easily modified further with the addition of functional materials.