The electrochemical enhancement due to the aligned structural effect of carbon nanofibers in a supercapacitor electrode

Aligned carbon nanofibers (ACNFs) were fabricated by electrospinning using a high speed of rotary collector (2000 rpm). To achieve a synergy effect of the electron double layer and redox faradaic reaction, NiCo 2 O 4 was deposited on the surface of the ACNFs using an electrodeposition method. The improved electrochemical performance of the electrodes was investigated by cyclic voltammetry, galvanostatic charge-discharge testing, and electrochemical impedance analysis. Among the prepared electrodes, which were deposited for different times (5, 10, 20, and 30 s), the sample deposited by NiCo 2 O 4 for 10 s had the highest specific capacitance (90.1 F g −1 at 5 mV s −1 ), good rate capability (64.7%), and cycle stability (85.2% after 1000 cycles). In addition, to examine the effects of the alignment and redox faradaic reaction of NiCo 2 O 4, the ACNFs covered with NiCo 2 O 4 for 10 s (NC-ACNFs) were compared with the ACNFs deposited by Co 3 O 4 (C-ACNFs) and randomly oriented carbon nanofibers covered with NiCo 2 O 4 (NC-RCNFs) . The NC-ACNFs had a 15.8% and 11.3% higher specific capacitance than that of the C-ACNFs and NC-RCNFs, respectively. These results suggested that the electrochemical properties of carbon nanofibers could be improved through the structural effects of aligned nanofibers and a redox faradaic reaction of NiCo 2 O 4 .