Hierarchical porous carbon obtained from directly carbonizing carex meyeriana for high-performance supercapacitors

Hierarchical porous carbon materials with high surface area are facilely prepared by directly carbonizing carex meyeriana without any extra activation procedure. The as-prepared porous carbon samples possess high Brunauer-Emmett-Teller (BET) surface areas (in the similar to 518-742 m(2) g(-1) range) and unique hierarchical porous structure containing macropore channels and mesopores and micropores developed in the wall of macropores. These intriguing characteristics make the as-prepared hierarchical porous carbon samples a promising electrode material for supercapacitors. The capacitive performance was measured in the three-electrode system with 6 M KOH electrolyte. The hierarchical porous carbon prepared at the carbonization temperature of 1000 degrees C presents a high specific capacitance of 178.6 F g(-1) at a current density of 0.5 A g(-1), a good rate performance (about 65.2% retention ratio at the current density of 20 A g(-1)), and an excellent cycling stability (no obvious performance fading after 10,000 cycles). In addition, the fabricated two-electrode device achieves an energy density of 4.33 Wh kg(-1) at a high power density of 5 kW kg(-1). These results provide a green and facile method to synthesize the electrode material from biomass for high-performance supercapacitors.

Automated summary

Carbon materials derived from carex meyeriana show high surface area and unique hierarchical porous structure, making them promising electrode materials for supercapacitors. These materials exhibit excellent capacitive performance, energy density, and power density in a KOH electrolyte, providing a green and facile method for high-performance supercapacitors.