High Performance Symmetric Supercapacitor Based on Sunflower Marrow Carbon Electrode Material

In this study, sunflower marrow is used as raw material to prepare porous carbon via a simple carbonization method activated by ZnCl 2 and FeCl 3 mixture. The as-prepared porous sunflower marrow carbons (PSMCs) show large number of mesoporous and masoporous, maximum specific surface area of 1628.5 m 2 g -1 and large pore volume of 2.34 cm 3 g -1 . As an electrode material for supercapacitor, the PSMCs possess high specific capacitance of 252.5 F g -1 at 0.5 A g -1 . A symmetric supercapacitor used PSMCs as electrodes exhibits energies density of 12.4 Wh kg -1 at a power density of 817 W kg -1 operated in the voltage range of 0-2.0 V in 0.5 mol L -1 Na 2 SO 4 aqueous electrolyte. Also, the carbon material shows excellent cycleability retains about 97% initial capacitance after 5000 cycles.