Fish gill-derived activated carbon for supercapacitor application

Fish gill-derived porous activated carbon (FGAC) has been successfully prepared by simultaneous carbonization and activation. The FGAC composed of cross-linked thin carbon nanosheets reveals large specific surface area, wide-range hierarchical porous structure and appropriate contents of oxygen and nitrogen functional groups. As a supercapacitor electrode material, the FGAC shows high specific capacitance of 334 F g−1 at 2 A g−1 in 6 M KOH, good electrochemical stability and excellent rate capability (only 7% capacitance fading when the current density is increased by 20 times). These attractive electrochemical performances are ascribed to the multiple synergistic effects of the structure and chemistry of the FGAC, which can not only facilitate ion diffusion, transport and adsorption, but also increase surface area for charge accumulation.