Electrospun NiO/C nanofibers as electrode materials for hybrid supercapacitors with superior electrochemical performance

In this work, the porous NiO/C nanofibers (NFs) were rationally designed and prepared by a convenient electrospinning method, and followed with a calcination conversion of the precursor in air. The NiO/C composite exhibited a net-like structure that was composed of many intertwined NFs with an average diameter of about 200 nm. The electrochemical measurements demonstrated that the porous NiO/C NFs exhibited an electrochemical feature of battery-type electrode material, and delivered a specific capacity as high as 461.26 C g−1 under 1 A g−1 and an excellent rate capability with 82.7% capacity retention at 10 A g−1. A hybrid supercapacitor (NiO/C NFs//AC HSC) was assembled with NiO/C NFs as positive electrode and activated carbon (AC) as negative electrode, which delivered an energy density of 31.82 W h kg−1 under a power density of 816.36 W kg−1 along with an outstanding cyclic stability of 90.9% capacity retention over 5000 cycles at 5 A g−1. This simple synthetic method can be extended to the fabrication of other transition metal oxides (TMOs)-based NFs for their further applications in high-performance electrochemical energy storage devices such as hybrid supercapacitors, batteries, and so on.