Flour food waste derived activated carbon for high-performance supercapacitors

It is of great importance to develop electrode materials at a low cost for constructing high-performance electrochemical energy storage systems. Herein, we employed flour food waste residue as a raw material to prepare porous carbon based supercapacitor electrodes through the carbonization and subsequent KOH activation process. The as-prepared biomass-derived activated carbon exhibits an interconnected porous network with numberous open micropores and appropriate mesopores. Meanwhile, its moderate total pore volume results in a high mass density of 0.86 g cm^-3. When used as supercapacitor electrodes in an aqueous solution of KOH (6 mol L^-1), the porous carbon material shows a high specific capacitance (278 F g^-1, 241 F cm^-3) and good cycling stability with 95% capacitance retention over 3000 cycles at a current density of 2 A g^-1. Furthermore, even at an ultrahigh current density of 100 A g^-1 (charge/discharge completed within 3 s), it still maintains a high specific capacitance of 142 F g^-1 (122 F cm^-3).