(554b) Interfacial Polymerized Polyaniline Nanofibers/Graphite Oxide Composites Toward Electrochemical Capacitors

Polyaniline nanofibers (PANI-NFs)/graphite oxide (GO) nanocomposites with excellent interfacial interaction and elongated fiber structure were synthesized via a facile interfacial polymerization method. This polymerization method efficiently exfoliates the expanded layer structure of GO into individual sheet and thus significantly enhances the specific surface area. Direct evidence of a strong interaction between PANI-NFs and GO was observed from TEM. The reduced diameter of PANI-NFs in PANI-NFs/GO than that of pure PANI-NFs can shorten the diffusion distance and enhance the electro-active sites. The PANI-NFs/GO hybrid materials showed orders of magnitude enhancement in capacitance and energy density than those of individual GO and PANI-NFs. The higher PANI-NFs fraction in composites generates larger energy density, which can be as high as 25.4 Wh/kg at the power density of 288 W/kg. The enlarged electrochemical capacitance of PANI-NFs/GO is attributed to the increased specific surface area, which improves the accessibility of ions from electrodes to electroactive materials as well as the improved conductivity due to the excellent interfacial interaction. At a same weight loading of PANI in the composites, fibrous PANI shows higher energy density than that of particle-shaped PANI at higher power density. These findings open up a new window of GO-based composites for the capacitor applications with high energy and power densities.