(181n) Synthesis of Supercapacitor Electrodes Based on Polyaniline Microfibers Using a Novel Electrospinning Architecture

Electrospinning is a simple and versatile method for producing nano- or micro- scale fibers from a wide variety of materials that includes polymers, composites, and ceramics. Electrospinning is favored over other methods to produce nanocomposites because of its ability to synthesize fibers with high surface area to volume ratio and its ease of use in various applications. In this work, we report on the successful formation of highly aligned and conductive, electrospun polyaniline fibers using ‘secondary dopants’. We also report the electrospinning of polymers from high boiling point solvents (202 °C) at a relatively low voltage (20-25 kV) using a novel rotating drum system. This represents an inexpensive and scalable method to produce highly conductive fibers in one-step. Low-volatility solvents, such as m-cresol (one of the highest boiling point solvent to be electrospun from thus far), can act as a secondary dopant of polyaniline and was used to test the effectiveness of this technique, enabling the production of polyaniline micro fibers with conductivities of 1.7 ± 0.3 S/cm. This value is two-orders of magnitude higher than the average value of polyaniline nanofibers reported in literature. This polymer is stable at temperatures up to 200˚C. These conductive fibers are also being tested as electrodes for supercapacitors. The ease of making these electrodes with just the elctrospun fibers without any addition of porous carbon or binder makes this approach both flexible and versatile. In the preliminary experiments, the specific capacitance of the electrospun fibers was found to be as high as 450 F/g at a scanning speed of 0.01 V/s. Detailed work has also been carried out to find out the band gap and absorbance change using UV-VIS spectroscopy on application of different potential to study the electrochromic properties of these fibers.