Economic prosperity of developing flixweed seeds-derived porous carbon for ultrahigh-performance supercapacitors

The fabrication of carbon materials with low cost and high performance is the main challenge in wide appli-cations of supercapacitors. In this work, facile carbonization and chemical activation processes are developed to convert flixweed seeds to hierarchical porous carbon with large specific surface area and self-doped ample heteroatoms (e.g., nitrogen, sulfur and oxygen). The obtained carbon material demonstrates several advantages in supercapacitors, such as ultrahigh specific capacitance of 662.4 F g-1 at 0.5 A g-1 and long cycling life > 12,000 cycles at 20 A g-1. A symmetric supercapacitor based on the resulting carbon delivers a high energy density of 34 W h kg-1 at 1000 W kg-1 in 1 M Na2SO4. Therefore, flixweed seeds can be economically utilized for large-scale production of porous carbon with excellent supercapacitance performance.