Tuning N/O-doped carbon materials for supercapacitors by direct pyrolysis of imidazolinium polymer

Abstract

Using structurally adjustable polymer to develop pseudocapacitive carbon materials with rich faradaic-active functionalities in the readily accessible skeleton for supercapacitors is important and still challenging. In this paper, using the “aromatic aldehydes ammonia condensation” idea and starting from the terephthalaldehyde and ammonium, highly pseudocapacitive active porous carbon materials were fabricated by simple “one pot method” and pyrolysis. The iodine-modified imidazolinium network polymer synthesized carbon at 700 °C (INP-I-700) shows a high specific surface area (606 m2 g−1) and pore volume of 0.30 cm3 g−1. Thanks to the hierarchically microporous, mesoporous and macroporous structure and diverse pseudocapacitive active N,O species, the ammonium iodide synthesized imidazolinium polymer derived INP-I-700 porous carbon material demonstrates a high specific capacitance of 199.1 F g−1 at 1 A g−1, along with superior cycling stability for symmetric supercapacitor configure with 99 % capacity retention after 10,000 cycles in 1 M Na2SO4 aqueous electrolyte. Furthermore, an attractive energy density of 27.7 Wh/kg at power density of 496.5 W/kg in Na2SO4 electrolyte in the voltage range of 0–2.0 V for the assembled symmetric system can be reached. The outcome of this paper can provide guidance for the construction of functionalized carbon-based materials with large specific surface area.