Strong interaction between polyaniline and carbon fibers for flexible supercapacitor electrode materials

Abstract

In this paper, we synthesize a polyaniline (PANI) grafted with carbon fiber (CF) composite (PANI-g-CF) linked by amide group (–NH–CO) covalent bond for flexible supercapacitor (SC) electrode material. The –NH–CO covalent bond enhances the interaction between the PANI and CF, which is confirmed by infrared spectroscopy, Raman spectrum, and X-ray photoelectron spectroscopy. The PANI-g-CF also extends π-conjugated electrons from CF to PANI, which is revealed by Ultraviolet and visible spectrum and nuclearmagnetic resonance spectroscopy. Due to the strong interaction and π-conjugated electrons, the PANI-g-CF exhibits highly electronically conductivity and benefits rapid charge transfer for charge storage. As a SC electrode material, the PANI-g-CF exhibits specific capacitance of 441F g−1at 1 A g−1with rate capability of 75.43% from 1 A g−1 to 10 A g−1. Especially, PANI in PANI-g-CF possesses high specific capacitance of 1178 F g−1, suggesting the ultra-utilization of PANI for SCs. Due to the ultra-intimate contact of the PANI and CF, The assembled flexible SC using PANI-g-CF as electrode materials shows highly stability in long-term cycle with 88.80% and 92.9% of the initial capacitance after 10,000 cycles and mechanical folding 2000 times, respectively.