One-step synthesis of polymer based N-doped porous carbon with enriched nitrogen content and its enhanced electrochemical properties in supercapacitors

作者：Zhang, Yude; Deng, Fuyao; Zhang, Qian^*; Xing, Baolin; Shang, Jinli; Lin, Jia

来源：Journal of Energy Storage, 2022, 55: 105494.

DOI：10.1016/j.est.2022.105494

• N-doped porous carbon
• One-step strategy
• Co-pyrolysis
• Polymer
• Supercapacitor

N-doped porous carbon (N-PC) is considered as a promising candidate for electrochemical energy storage. However, the complicated multistep process is the biggest bottleneck. Here, a facile one-step strategy was employed to fabricate the N-doped porous carbon via the co-pyrolysis of urea and poly(acrylic acid-co-maleic acid) sodium salt (PAMS) without the protection of inert gas at 550 degrees C. When the mass ratio of urea to PAMS is 4:1, the microstructure and electrochemical properties of the as-prepared sample (N-4PC) are obviously improved compared with that of the direct carbonization of PAMS (PC). N-4PC presents salient peculiarities with much more mesopores, higher specific surface area of 181.5 m(2) g(-1) far more than PC (23.6 m(2) g(-1)), and its nitrogen content is up to 10.61 at. %. In a three-electrode configuration using 6 M KOH, owing to the synergistic effect of pyridinic N, pyrrolic N and graphitic N atoms, N-4PC shows an outstanding specific capacity of 210 F g(-1) far more than that of PC (93 F g(-1)) at 1 A g(-1), and a significant capacity retention rate of 79 % much higher than PC (47 %) at 20 A g(-1). Furthermore, the symmetric supercapacitor fabricated by N-4PC delivers an attractive specific capacitance of 140 F g(-1) at 1 A g (-1), and 4.9 Wh kg(-1) energy density when the power density is 265 W kg(-1) in 6 M KOH. The equipment achieves superior cycle stability with capacity retention of 97 % after 7000 cycles at 1 A g(-1). Additionally, N-4PC also achieves great energy densities of 6.7 Wh kg(-1) at the power density of 372.3 W kg(-1) in 1 M H2SO4 and 12.5 Wh kg(-1) at the power density of 521.5 W kg(-1) in 1 M Li2SO4. The fabricated nitrogen-doped porous carbon material has a great potential application prospect in energy storage equipment.