Supercapacitor Electrodes Based on High Purity Electrospun Polyaniline and Polyaniline Carbon Nanotube Nanofibers.
Freestanding, binder free supercapacitor electrodes based on high purity polyaniline (PANI) nanofibers were fabricated via a single step electrospinning process. The successful electrospinning of nanofibers with an unprecedentedly high composition of PANI (93 wt was made possible due to blending ultrahigh molecular weight poly(ethylene oxide) (PEO) with PANI in solution to impart adequate chain entanglements, a critical requirement for electrospinning. To further enhance the conductivity and stability of the electrodes, a small concentration of carbon nanotubes (CNTs) was added to the PANI/PEO solution prior to electrospinning to generate PANI/CNT/PEO nanofibers (12 wt CNTs) Scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) porosimetry were conducted to characterize the external morphology of the nanofibers. The electrospun nanofibers were further probed by transmission electron microscopy (TEM) X ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT IR) The electroactivity of the freestanding PANI and PANI/CNT nanofiber electrodes was examined using cyclic voltammetry, galvanostatic charge discharge, and electrochemical impedance spectroscopy. Competitive specific capacitances of 308 and 385 F g( 1) were achieved for PANI and PANI CNT based electrodes, respectively, at a current density of 0.5 A g( 1) Moreover, specific capacitance retentions of 70 and 81.4% were observed for PANI and PANI CNT based electrodes, respectively, after 1000 cycles. The promising electrochemical performance of the fabricated electrodes, we believe, stems from the porous 3 D electrode structure characteristic of the nonwoven interconnected nanostructures. The interconnected nanofiber network facilitates efficient electron conduction while the inter and intrafiber porosity enable excellent electrolyte penetration within the polymer matrix, allowing fast ion transport to the active sites.
ACS applied materials interfaces