A cheese-shaped bio-carbon for high performance supercapacitors prepared from Juncus effuses. L.

Biomass-derived carbon materials have received intensive attention, particularly in energy storage areas. A facile method for synthesis of cheese-shaped porous carbon using Juncus effuses. L. (JEL) as raw material was reported in this work. The JEL was activated by K2CO3 for 24h and then carbonized in N-2 atmosphere at 800 degrees C for 2h. By this means, a porous bio-carbon with a large specific surface area (2338 m(2) g(-1)) was obtained. When evaluated in a three-electrode system with 6M KOH solution as electrolyte, the as-prepared sample exhibited a high specific capacitance of 357 F g(-1) at 1 A g(-1) and a good rate performance with a capacitance of 280 F g(-1) at 20 A g(-1). It is expected that this green and facile technique could serve as an effective and scalable method to prepare porous structures from biomass for electrochemical energy storage applications.