Nitrogen and sulfur dual-doped hierarchical porous carbon derived from bacterial cellulose for high performance supercapacitor

Abstract

Improving the energy density of carbon-based supercapacitor is very attractive, but still a big challenge. Herein, we report a convenient way for the construction of nitrogen and sulfur dual-doped hierarchical porous carbon derived from bacterial cellulose using thiacetamide as nitrogen/sulfur source and ZnCl2 as activating agent. The obtained porous carbon displays unique porous structure with micrometer sized macropores between carbon skeleton serve as ion-buffering reservoirs to shorten ion diffusion distance, nanometer sized macropores and mesopores in the surface of carbon framework serve as high-speed channel to facilitate ion rapid transfer. Benefiting from the unique hierarchical porous structure, large specific surface area, and rich heteroatoms, the optimized samples (NSPC-700) display a large specific capacitance of 360 F g−1 at 1.0 A g−1, excellent rate characteristic and superior cycling durability. Significantly, the assembled symmetrical supercapacitor displays an energy density of 26.8 Wh kg−1 and superior electrochemical stabilization in 1 M Na2SO4 aqueous electrolyte.