The synthesis of mechanically stable polybenzoxazine-based porous carbon and its application as high-performance supercapacitor electrodes

Abstract

Nitrogen self-doped mesoporous carbon is synthesized from a novel polybenzoxazine and used as an electrode for supercapacitor applications. Two different types of carbon are derived from the same polybenzoxazine, which is synthesized from apigenin, furfuryl amine, and formaldehyde. Carbon derived from calcination is denoted as APFC-N and the other carbon type derived from an aerogel is denoted as APFC-G. The surface areas of APFC-N and APFC-G are found to be 248 and 635 m² g⁻¹, respectively. The pore size of APFC-G carbon is in the range of 2–5 nm, which is a suitable pore size for use as an electrode in electrochemical applications. The electrochemical properties of carbon obtained from the aerogel method (APFC-G) show good performance for supercapacitor applications with a specific capacitance of 120 F g⁻¹ at a current density of 0.5 A g⁻¹. At a low voltage scanning rate of <50 mV s⁻¹, a better rectangular shape is observed in the cyclic voltammogram of APFC-G. The impedance spectra of both carbon types agree well with the results of capacitance and the cyclic voltammogram analyses. Also, good cycling stability is retained, even after 25 000 continuous charge–discharge cycles.