3D stack tubular mesoporous carbon derived from discarded sesame capsule shells for high-performance supercapacitors

As one of the main electrode materials of supercapacitors, biomass carbon material has attracted wide attention, on account of its low price, wide source and green environmental protection. In this work, we used the discarded sesame capsule shells as the source material and treated it simply with KOH activation, finally obtained the target products TMCK (KOH-activated derived tubular mesoporous carbon) by one-step carbonization. The TMCK represented high specific capacitances of 222.7 F g−1 at 1 A g−1 over a potential window of −1–0 V in 2 M KOH electrolyte. Besides, the capacitance retention reaches 92.9 % after 20,000 cycles at 5 A g−1, indicating excellent cycle stabilization of TMCK. Moreover, a symmetric supercapacitor showed an energy density of 6.9 Wh kg−1 at a power density of 600 W kg−1. What's more, it provides an inexpensive, uncomplicated and effective preparation programme for the design of porous carbon electrode derived from discarded sesame capsule shells for supercapacitors.