Strawberry-like carbonized cotton Cloth@Polyaniline nanocomposite for high-performance symmetric supercapacitors

In order to control the microstructure of polyaniline (PANI) and enhance the interfacial bonding between PANI and carbon substrate, a vacuum infiltration method is put forward to prepare functionalized carbonized cotton cloth (FCC)@PANI nanocomposite. In which, FCC is soaked in dilute PANI solution under vacuum to achieve the permeation adsorption of PANI. After the solvent evaporated, strawberry-like FCC@PANI nanocomposite is produced with PANI nanoparticles embedding on the fiber surface. This novel method effectively avoids the generation of PANI nanofibers and their agglomeration, even at a high PANI loading of 28.1 wt%. Serving as electrodes in symmetric supercapacitors, the optimum FCC@PANI composite exhibits the maximum capacitance of 350.8 F g⁻¹ (1859.2 mF cm⁻²) at 1 A g⁻¹, and a high capacitance retention of 90.8% for 10,000 cycles. The performance is much better than that of optimized FCC/PANI composite synthesized by in-situ polymerization, due to the low internal resistance, fast transfer of electrons/ions and a strong interfacial bonding interaction. In view of the easy operation and scalability, vacuum infiltration method has a promising prospect for preparing carbon fabrics/PANI composite electrodes in large scale.