Hierarchically Porous Carbon Cloth–Polyaniline (CC–PANI) Composite Supercapacitor Electrodes with Enhanced Stability

In this work, hierarchically porous composites were prepared in the form of activated carbon cloth (CC) Busofit T–1–055 filled with an electrically conductive polymer, polyaniline (PANI), for use as pseudocapacitive electrodes of electrochemical supercapacitors (SCs). CC fibers have high nanoporosity and specific surface area, so it was possible to deposit (via the chemical oxidative polymerization of aniline) a significant amount of PANI on them in the form of a thin layer mainly located on the inner surface of the pores. Such morphology of the composite made allowed the combining of the high capacitive characteristics of PANI with the reversibility of electrochemical processes, high columbic efficiency and cyclic stability rather typical for carbon materials of double-layer SCs. The highest capacitance of composite electrodes of about 4.54 F/cm2 with high cyclic stability (no more than 8% of capacity loss after 2000 charge–discharge cycles with a current density of 10 A/cm2) and columbic efficiency (up to 98%) was achieved in 3 M H2SO4 electrolyte solution when PANI was synthesized from an aniline hydrochloride solution with a concentration of 0.25 M. Trasatti analysis revealed that 27% of specific capacitance corresponded to pseudocapacitance, and 73% to the double-layer capacitance.