Improving the electrochemical and physical properties of nickel cobaltite /polyacrylonitrile nanocomposites for supercapacitor applications

Abstract

Nanocomposite films composed of polyacrylonitrile (PAN) doped with nickel cobaltite (NCO) nanoparticles (NPs) with different weight ratios have been prepared and characterized. Field emission scanning electron microscopy (FE-SEM) confirmed that the NCO NPs were successfully incorporated into the PAN matrix. The x-ray diffraction (XRD) studies showed that the PAN degree of crystallinity was lowered by the incorporation of NCO NPs in the polymer matrix. Other various characterization techniques including energy dispersive x-ray (EDX), Fourier transform infrared (FTIR), and thermal analysis were used. In addition, the effect of NCO NPs on the dielectric permittivity and ac-conductivity exhibits that the ac conductivity of PAN is enhanced from 0.06 ×10− 4 to 3.19 ×10− 4 S m−1 by doping with 10 wt% NCO NPs at room temperature (RT) and 1.0 MHz. Moreover, the optical properties showed that the NCO/PAN nanocomposites revealed lower transmittance and narrowed the optical bandgap (E g) of the PAN from 3.92 to 3.37 eV. Cyclic voltammetry (CV), and galvanostatic charge–discharge (GCD) tests were performed to investigate the electrochemical behavior of the studied nanocomposites. It was found that PAN loaded with 10 wt% NCO NPS attains an excellent specific capacitance of 1241 F g−1 at a current density of 0.5 A/g. Also, the cycling stability is significantly enhanced, and the capacitance retention rate approaches 93.2% after 5000 cycles, which provides the possibility of using the studied nanocomposite films for supercapacitor applications.