Silk-derived nitrogen-doped porous carbon electrodes with enhanced ionic conductivity for high-performance supercapacitors

Supercapacitors are attracting extensive attention in energy storage fields thanks to their high safety, costeffectiveness, and environmental friendliness. The carbon materials, especially for the porous carbon materials derived from renewable biomass materials, are important electrode materials with cost-effective feature for supercapacitors. However, the inferior ionic conductivity of biomass materials inhibits their electrochemical performance in energy storage devices. Herein, an immiscible liquid-mediated method is provided to improve the ionic conductivity of silk-derived nitrogen-doped porous carbon (NPC) electrodes. Natural Bombyx mori (silkworm) silk is used as a carbon source for the preparation of electrode of supercapacitor. Further introducing immiscible organic liquid into the NPCs promotes the ion transport in the inner pores of the electrodes. With the assistance of organic liquid, the supercapacitor presents a specific capacitance of 565.3 F g-1 at a current density