Hierarchical porous carbon materials derived from N, O, S-Containing Bio-Based polybenzoxazine for Supercapacitors

Abstract

Supercapacitors (SCs) play a crucial role in modern society due to their energy storage capabilities, but their widespread use is limited by their low energy density. To address this challenge, we developed a simple and sustainable synthesis method using a soft template and mild activation strategy (g-C3N4 and KHCO3) to produce N, O, and S-doped hierarchical porous carbons (NOSHPCs) made from a new bio-based polybenzoxazine. The resulting NOSHPCs exhibit a large specific surface area of 1,888 m2/g, a large pore volume of 1.53 cm2/g with a micro-, meso-, and macro- porous structure, and introduce more nitrogen atom in carbon surface by in-situ and ex-situ methods, the maximum content of N atom can reach 10.52 at%. The best electrode material (NOSHPCs-1:2:2) in a three-electrode system showed a specific capacitance of 216.5F/g at 0.5 A/g, attributed to the combination of active function groups and a rich porous structure. The symmetrical SCs exhibit an energy density of 5.67 Wh kg−1 at 275 W kg−1 using a KOH electrolyte, and exhibit excellent cycling stability (capacitance retention rate reach 90.38 % after 5000 cycles). This research not only provides an efficient way to synthesize hierarchical porous carbons, but also introduces a new bio-based polybenzoxazine material.