3D nitrogen and sulfur co-doped hierarchical porous carbon derived from mung bean jelly for high performance supercapacitors

Abstract Design and preparation of biomass derived heteroatom-doped hierarchical porous carbons with excellent capacitive performances draw extensive research attention for supercapacitors. Herein, 3D nitrogen and sulfur co-doped hierarchical porous carbon (NSHPC) derived from mung bean jelly with mung bean starch as carbon source and thiourea as both nitrogen source and sulfur source is successfully prepared. By virtue of manipulating the preparation method, the obtained NSHPC possesses a high specific surface area of 2420 m2 g-1 and a large total pore volume of 1.64 cm3 g-1. The NSHPC electrode displays a high specific capacitance of 330.2 F g−1 at the current density of 0.5 A g−1 and still maintains 66.2% of its original specific at the high current density of 20 A g−1 in three-electrode system. In addition, a symmetric device based on NSHPC electrodes delivers an energy density of 8.3 W h kg−1 at the power density of 101.6 W kg−1, and more than 70.6% of energy density is kept even under the high power density of 19.3 kW kg−1. This study provides a facile and efficient method of applying biomass as a precursor to obtain heteroatom-doped hierarchical porous carbons for high performance supercapacitors.