LAUSR

Nitrogen-doped hierarchical porous electrospun carbon nanofibers (HPECNFs) were successfully prepared via electrospinning using ball-milled SBA-15 [well-ordered hexagonal mesoporous silica structures (Zhao et al., in Science 279(5350):548)] as hard template. As expected, ball milling enhances the dispersion of the SBA-15 template in the precursor of electrospinning, which makes the obtained HPECNFs to have a well-balanced distribution of the micro-, meso- and marco-pores. The HPECNFs exhibit free-standing structures, high specific surfaces and rich nitrogen-containing groups derived from pyrolysis of polyacrylonitrile (PAN), which boost the electrochemical performance of HPECNFs considerably. As a binder-free electrode material, the HPECNFs display a high capacitance of 250 F g−1 at the current density of 0.5 A g−1 as well as excellent rate capability (132.5 F g−1 at 50 A g−1) and super cycling stability (negligible loss after 5000 cycles). Moreover, in a symmetric device, the supercapacitor device shows the highest energy density of 12.91 Wh kg−1 at the power density of 325 W kg−1.