A novel sustainable cornstalk-derived porous carbon composited with in-situ polymerized polyaniline nanowires for high-performance asymmetric supercapacitors

Abstract

In this work, a novel renewable cornstalk-derived porous carbon/polyaniline (PC/PANI) composite used as the electrode material for high-performance asymmetric supercapacitors is synthesized by a facile in-situ polymerization of aniline in the presence of cornstalk-derived PC. The three-dimensional hierarchical PC is successfully prepared by a KOH activation route combined with sodium chloride (NaCl) and potassium chloride (KCl) as the salt templates and cornstalk as carbon source, which the specific surface area reaches 1181.6 m2·g−1. As an electrode material, the PC/PANI possess a high specific capacitance of 1041.2 F·g−1 at 0.5 A g−1 in 1 M H2SO4 electrolyte, compared with the bare PC (234.1 F·g−1) or single PANI (335.6 F·g−1). Moreover, what is noteworthy is that the asymmetric supercapacitor based on PC/PANI electrode exhibits high energy density (31.2 Wh·kg−1) and power density (8135.2 W·kg−1) in a voltage window of 0–1.8 V, as well as an excellent cycling stability (91.2 % capacitance retention over more than 10,000 cycles), revealing that the superior properties of PC/PANI electrode have a substantial promotion for the development of high-performance supercapacitors.