Soybean meal-derived heteroatoms-doped porous carbons for supercapacitor electrodes

The precursor (soybean meal) was directly pyrolyzed to fabricate N, O co-doped hierarchical porous carbons (HPCs) through NaCl/KCl/KHCO3 molten salt method. The obtained HPCs possess a well-developed 3D hierarchical porous structure with a maximum specific surface area of 1945 m2 g-1. Such a phenomenon is conducive to ion storage and transmission. In addition, abundant heteroatoms had been successfully incorporated into the HPCs, endowing additional pseudocapacitance to the carbon materials. Hence, HPC-3 could achieve a maximum specific capacitance of 507 F g-1 in 1 M H2SO4 electrolyte when the current density was 0.2 A g-1. Moreover, the supercapacitor cell assembled from two identical HPC-3 electrodes can achieve a reasonably high energy density of 12.4 Wh kg-1 at a power density of 50 W kg-1. Consequently, KHCO3 is a good pore-forming agent, and the obtained high-performance electrode material has broad prospects for supercapacitor application.

Automated summary

In this study, N, O co-doped hierarchical porous carbons (HPCs) were fabricated directly from soybean meal through the molten salt method. The resulting HPCs exhibited a well-developed 3D hierarchical porous structure with a high specific surface area, facilitating ion storage and transmission. By incorporating abundant heteroatoms into the carbon materials, additional pseudocapacitance was achieved. The HPC-3 electrode demonstrated a maximum specific capacitance of 507 F g-1 in 1 M H2SO4 electrolyte and the supercapacitor cell assembled from HPC-3 electrodes exhibited a relatively high energy density of 12.4 Wh kg-1 at a power density of 50 W kg-1. This research highlights the potential application of KHCO3 as a pore-forming agent and the obtained high-performance electrode material for supercapacitors.